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Purpose: To investigate the effects of transcranial direct-current stimulation (tDCS) applied over the primary motor cortex (M1) and cerebellum on balance control and shooting accuracy in elite ice hockey players. Methods: Twenty-one elite ice hockey players underwent anodal tDCS over the M1 (a-tDCSM1), anodal tDCS over the cerebellum (a-tDCSCB), concurrent dual-site anodal tDCS over the M1 and the cerebellum (a-tDCSM1+CB), and sham stimulation (tDCSSHAM). Before and after receiving tDCS (2 mA for 15 min), participants completed an ice hockey shooting-accuracy test, Pro-Kin balance test (includes stance test and proprioceptive assessment), and Y-balance test in randomized order. Results: For static balance performance, the ellipse area in the 2-legged stance with eyes open and the 1-legged stance with the dominant leg significantly improved following a-tDCSM1, a-tDCSCB, and concurrent dual-site a-tDCSM1+CB, compared with tDCSSHAM (all P <.05, Cohen d = 0.64–1.06). In dynamic balance performance, the average trace error of the proprioceptive assessment and the composite score of the Y-balance test with the dominant leg significantly improved following a-tDCSM1 and concurrent dual-site a-tDCSM1+CB (all P <.05, Cohen d = 0.77–1.00). For the ice hockey shooting-accuracy test, shooting-accuracy while standing on the unstable platform significantly increased following a-tDCSM1 (P =.010, Cohen d = 0.81) and a-tDCSCB (P =.010, Cohen d = 0.92) compared with tDCSSHAM. Conclusion: tDCS could potentially be a valuable tool in enhancing static and dynamic balance and shooting accuracy on unstable platforms in elite ice hockey players. [ABSTRACT FROM AUTHOR]

Objectives: The static and dynamic correlations of postural stability to its three potential contributors, namely, proprioception, tactile sensation, and strength remain unclear among people with chronic ankle instability (CAI). This study aimed to compare static and dynamic postural stability, along with proprioception, tactile sensation, and strength between people with and without CAI and explore their correlations. Methods: Sixty-seven participants with CAI and 67 participants without CAI were enrolled in this study. Ankle proprioception, plantar tactile sensation, and lower limb strength were measured by a proprioception test device, a set of monofilaments, and a strength testing system, respectively. Static and dynamic postural stability were measured during standing and jump landing on a force plate and indicated by the root mean square of center of pressure and time to stability. Results: Compared to people without CAI, people with CAI had poorer postural stability, proprioception, tactile sensation, and strength. Both groups demonstrated correlation between proprioception and static postural stability, but only people without CAI showed correlation between proprioception and dynamic postural stability. Both groups demonstrated a correlation between tactile sensation and static postural stability, but not with dynamic stability. Both groups demonstrated a correlation between strength and both static and dynamic postural stability. Conclusions: People with CAI had deficits in static and dynamic postural stability, proprioception, tactile sensation, and strength. Among people with CAI, proprioception, tactile sensation, and strength can help maintain static postural stability; strength can help maintain dynamic postural stability, whereas proprioception may not provide sufficient information for dynamic postural stability. [ABSTRACT FROM AUTHOR]

Falls are very serious health concerns among older adults. Providing additional cutaneous and proprioceptive feedback to older adults may enhance their balance control and therefore reduce the incidents of falls. This study aimed to investigate the acute and acclimated effect of wearing waist-to-above-ankle compression garments (CGs) on balance control in community-dwelling older adults. Thirty-one older adults participated in the study. The Timed Up and Go, Berg Balance Scale, and the Fall Risk Test of the Biodex Balance System were used in a random order to examine balance control in three testing sessions 1 week apart. Results indicated wearing CGs had a significant impact on the Timed Up and Go test (p <.001), Berg Balance Scale (p =.001), and the Fall Risk Test (p =.001). For the Timed Up and Go test, participants exhibited significant improvement in both the acute (8.68 vs. 7.91 s) and acclimated effect (7.91 vs. 7.41 s) of wearing CGs. For the Berg Balance Scale, participants showed significant improvement after wearing CGs for 1 week in comparison to the no CGs condition (55.77 vs. 55.39 points). For the Fall Risk Test, participants showed a significant improvement in the acute effect of wearing CGs in comparison to the no CGs condition (1.55° vs. 1.31°). This exploratory study showed that wearing waist-to-above-ankle CGs provided a positive impact on balance control in healthy community-dwelling older adults. It lays the foundation for future studies with a larger sample size to investigate the potential benefits of wearing CGs in individuals with balance control deficits and/or other comorbidities. [ABSTRACT FROM AUTHOR]

We have previously shown evidence that some individuals seem to consistently minimize low back loads when lifting. while others do not. However, it is unknown why. Individual differences in ability to perceive relevant sensory information may explain differences in minimization of low back loads during lifting, consistent with considering load reduction in one's movement objective in an optimal feedback control theory framework. The purpose of this study was to investigate whether individuals' ability to perceive proprioceptive information (both force- and posture-senses) at the low back was associated with peak low back loads when performing generic or occupation-specific lifts. Seventy-two participants were recruited to perform 10 barbell (generic) and backboard (occupation-specific) lifts, while whole-body kinematics and ground reaction forces were collected. Peak low back compression and anteroposterior shear forces normalized to body mass were calculated as dependent variables. Both posture matching ability and force matching ability at the heavier force targets were associated with lower means and variability of peak low-back loads in both lift types, albeit with small effect sizes (R² 5.17). These findings support the utility of an optimal feedback control theory framework to explore factors explaining interindividual differences in low back loads during lifting. Further, this evidence suggests improving proprioceptive ability may be a useful strategy in lift training programs designed for workplace injury prevention. [ABSTRACT FROM AUTHOR]

Proprioception is essential for precise movement as it helps the body transmit important data about its surroundings to the central nervous system for maintaining body posture and position. This study aimed to investigate the effect of direction and joint angle on upper limb proprioception. Thirty individuals (all males) completed a position reproduction activity in 13 directions and three joint angles. It was discovered that upper limb proprioception is dependent on joint angle, direction, and range of motion. The position reproduction error was found to be dependent on the direction, which had a significantly lower accuracy in the direction with a larger range of motion. In addition, upper limb repositioning errors increased at greater limb elevation angles. Our findings also showed that the joint angle did not significantly affect the absolute error of elbow flexion. With an increase in the elbow flexion, the increase of the gravitational moment of the upper arm and hand coupled with the increase of the muscle arm of the biceps brachii possibly causes slight changes in muscle length perceived by spindles or muscular force perceived by Golgi tendon organs. [ABSTRACT FROM AUTHOR]

Background: Individuals with visual impairment have balance deficits; therefore, this systematic review aimed to provide comprehensive insights into the balance control of individuals with visual impairments when compared with individuals with full vision. Methods: Primary sources were obtained from eight databases including PubMed. LILACS, Science Direct, SCOPUS, CINAHL. PEDro, CENTRAL. and Web of Science. The search period covered years from inception to January 10, 2022. Results: A total of 20 studies with 29 trials with 1,280 participants were included in the systematic review. The results showed that individuals with sight had better static and dynamic balance than individuals with visual impairment (p = .001). However, individuals with visual impairment had significantly better static balance with visual perturbation and stronger static balance with visual and proprioception perturbation (p = .001). Furthermore. individuals with sight had better balance control than individuals with visual impairment who participated in sports (p = .001). Finally, individuals with visual impairment who participated in sports had better balance control than sedentary people with visual impairment (p = .001). Conclusion: individuals with visual impairment have defects in both dynamic and static balance when compared to individuals with sight. In addition. balance improved with increasing age in individuals with visual impairment while balance control was dependent on the proprioception and vestibular systems. Also, individuals with sight had better balance than individuals with visual impairment who participated in sports and individuals with visual impairment who participated in sports compared with sedentary people with visual impairment. [ABSTRACT FROM AUTHOR]

Mechanical metamaterials have recently been exploited as an interesting platform for information storing, retrieval and processing, analogous to electronic devices. In this work, we describe the design and fabrication a two-dimensional (2D) multistable metamaterial consisting of building blocks that can be switched between two distinct stable phases, and which are capable of storing binary information analogous to digital bits. By changing the spatial distribution of the phases, we can achieve a variety of different configurations and tunable mechanical properties (both static and dynamic). Moreover, we demonstrate the ability to determine the phase distribution via simple probing of the dynamic properties, to which we refer as mechanical proprioception. Finally, as a simple demonstration of feasibility, we illustrate a strategy for building autonomous kirigami systems that can receive inputs from their environment. This work could bring new insights for the design of mechanical metamaterials with information processing and computing functionalities. This article is part of the theme issue 'Origami/Kirigami-inspired structures: from fundamentals to applications'. [ABSTRACT FROM AUTHOR]

[Display omitted] • EEG can track modulation of cortical proprioceptive processing to joint rotations. • Volitional muscle activation intensifies the cortical proprioceptive processing. • Cortical inhibition is enhanced during passive joint-rotation stimulation. • Mechanisms likely at muscle, spinal, sub-cortical and cortical levels. Cortical proprioceptive processing of intermittent, passive movements can be assessed by extracting evoked and induced electroencephalographic (EEG) responses to somatosensory stimuli. Although the existent prior research on somatosensory stimulations, it remains unknown to what extent ongoing volitional muscle activation modulates the proprioceptive cortical processing of passive ankle-joint rotations. Twenty-five healthy volunteers (28.8 ± 7 yr, 14 males) underwent a total of 100 right ankle-joint passive rotations (4° dorsiflexions, 4 ± 0.25 s inter-stimulus interval, 30°/s peak angular velocity) evoked by a movement actuator during passive condition with relaxed ankle and active condition with a constant plantarflexion torque of 5 ± 2.5 Nm. Simultaneously, EEG, electromyographic (EMG) and kinematic signals were collected. Spatiotemporal features of evoked and induced EEG responses to the stimuli were extracted to estimate the modulation of the cortical proprioceptive processing between the active and passive conditions. Proprioceptive stimuli during the active condition elicited robustly ∼26 % larger evoked response and ∼38 % larger beta suppression amplitudes, but ∼42 % weaker beta rebound amplitude over the primary sensorimotor cortex than the passive condition, with no differences in terms of response latencies. These findings indicate that the active volitional motor task during naturalistic proprioceptive stimulation of the ankle joint enhances related cortical activation and reduces related cortical inhibition with respect to the passive condition. Possible factors explaining these results include mechanisms occurring at several levels of the proprioceptive processing from the peripheral muscle (i.e. mechanical, muscle spindle status, etc.) to the different central (i.e. spinal, sub-cortical and cortical) levels. [ABSTRACT FROM AUTHOR]

Alpine skiing poses significant risks for anterior cruciate ligament (ACL) injury at both recreational and professional levels, which is compounded by high rates of re-injury. Despite the existence of return to sport (RTS) and return to snow protocols, the frequency of ACL re-injury has not been mitigated, raising doubts about protocol effectiveness. Current RTS protocols primarily focus on biomechanical and neuromuscular factors in isolation, neglecting the important perceptual-motor-cognitive changes associated with ACL injuries and the high cognitive demands of skiing. The purpose of this clinical commentary is to address the perceptual-motor-cognitive demands specific to alpine skiing, evaluate RTS testing for skiers, and propose updated standards for testing and return to snow progressions that incorporate these considerations. [ABSTRACT FROM AUTHOR]

Background Dynamic postural control (DPC) describes an individual's ability to maintain balance within their base of support in both anticipatory and reactive balance situations and has been measured using center of pressure (COP) velocity. Common standardized DPC assessments for active adults include the modified Star Excursion Balance Test (MSEBT) and the Y-Balance Test (YBT). Hypothesis/Purpose The purpose of this study was to explore DPC during performance of the MSEBT, the YBT, and a modified version of the YBT, the MYBT. It was hypothesized that feedback from the YBT/MYBT reach indicator would enhance DPC. Study Design Cross-sectional study Methods Twenty-one participants (9 females, 12 males, mean age 24.5±1.2 years) performed three trials in each direction (anterior-AN, posteromedial-PM, and posterolateral-PL) on each balance test during one session. The YBT frame was placed atop a force plate for all testing. Frontal and sagittal plane COP velocities (COPx and COPy, respectively) were recorded throughout each trial and resultant COP (COPr) velocities were calculated. Results Significant main effects were present for test (F=4.485, p<0.001) and reach direction (F=61.594, p<0.001). Post hoc analyses for test indicated significant differences in COPy between YBT and MSEBT (p=0.034) and between MYBT and MSEBT (p<0.001), as well as significant differences in COPr between MYBT and MSEBT (p=0.002). Post hoc analyses for reach direction revealed significant differences in COPx between AN and both PM (p<0.001) and PL (p<0.001) directions, in COPy between AN and PM (p<0.001) and PL (p<0.001) directions, and COPr between AN and PL (p=0.043) directions only. Conclusion External proprioceptive feedback from the reach indicator improved DPC during the YBT and MYBT when compared to the MSEBT. Sagittal plane COP velocities were reduced when external proprioceptive feedback from the reach indicator was present, while frontal plane COP velocities were not affected in this group of participants. [ABSTRACT FROM AUTHOR]

This study aimed to systematically review and summarise the evidence about the effect of muscle fatigue on the knee proprioception of trained and non-trained individuals. A search in PubMed, Scopus, Web of Science and EBSCO databases and Google Scholar was conducted using the expression: "fatigue" AND ("proprioception" OR "position sense" OR "repositioning" OR "kinesthesia" OR "detection of passive motion" OR "force sense" OR "sense of resistance") AND "knee". Forty-two studies were included. Regarding joint-position sense, higher repositioning errors were reported after local and general protocols. Kinesthesia seems to be more affected when fatigue is induced locally, and force sense when assessed at higher target forces and after eccentric protocols. Muscle fatigue, both induced locally or generally, has a negative impact on the knee proprioception. [ABSTRACT FROM AUTHOR]

This study aimed to investigate whether patients with low back pain (LBP) had impaired lower limb proprioception and its association with somatosensory acuity. Thirty patients with LBP and 30 asymptomatic people volunteered, using Sway Discrimination Apparatus tests to assess somatosensory acuity during voluntary anteroposterior and mediolateral postural sway. Results showed significantly reduced somatosensory acuity in mediolateral sway in LBP patients (p = 0.005) with ankle, knee, and hip proprioception showing significantly impairment compared to asymptomatic controls (all p ≤ 0.012). Regression analysis showed that ankle and hip proprioception were significantly associated with somatosensory perception (0.001 ≤ p ≤ 0.026, 0.067 ≤ R2≤ 0.235). Overall, findings suggested a global deterioration of lower limb proprioception in LBP patients, with ankle and hip proprioception playing crucial role in somatosensory perception. [ABSTRACT FROM AUTHOR]

Poor postural control during jump landing may increase ankle sprain incidences among people with chronic ankle instability (CAI). The effects of anticipation on it and its relationship with proprioception need further examination. Fifteen participants with CAI and 15 healthy controls were recruited to perform single-leg jump landings when knowing the landing side before (planned) or after (unplanned) take-off respectively, along with a step-down proprioception test differentiating four inclination platforms (inverted 12°, 14°, 16° and 18°). Ground reaction force data (peak force, loading rate and time of stabilisation) during landings and proprioception scores were collected and analysed. The CAI group exhibited a higher loading rate (59.6 ± 7.6 vs 49.4 ± 6.7 N/kg*seconds, p = 0.011) and longer medial-lateral time to stabilisation (4.82 ± 0.69 vs 4.11 ± 0.47 seconds, p = 0.023) compared to the control group during an unplanned landing. Furthermore, the above variables were negatively correlated with the step-down proprioception score only in the unplanned condition but not in the planned condition. CAI participants had inferior medial-lateral time-to-stabilisation and loading attenuation during unplanned jump landing than healthy controls, which were associated with decreased proprioception, highlighting the importance of addressing proprioception to improve balance control during unpredictable landing situations. [ABSTRACT FROM AUTHOR]

Introduction: Proprioceptive error of estimated fingertip position in twodimensional space is reduced with the addition of tactile stimulation applied at the fingertip. Tactile input does not disrupt the participants' estimation strategy, as the individual error vector maps maintain their overall structure. This relationship suggests integration of proprioception and tactile information improves proprioceptive estimation, which can also be improved with trained mental focus and attention. Task attention and arousal are physiologically regulated by the reticular activating system (RAS), a brainstem circuit including the locus coeruleus (LC). There is direct and indirect evidence that these structures can be modulated by non-invasive trigeminal nerve stimulation (nTNS), providing an opportunity to examine nTNS effect on the integrative relationship of proprioceptive and tactile information. Methods: Fifteen right-handed participants performed a simple right-handed proprioceptive estimation task with tactile feedback (touch) and no tactile (hover) feedback. Participants repeated the task after nTNS administration. Stimulation was delivered for 10 min, and stimulation parameters were 3,000 Hz, 50 µs pulse width, with a mean of 7 mA. Error maps across the workspace are generated using polynomial models of the participants' target responses. Results: Error maps did not demonstrate significant vector direction changes between conditions for any participant, indicating that nTNS does not disrupt spatial proprioception estimation strategies. A linear mixed model regression with nTNS epoch, tactile condition, and the interaction as factors demonstrated that nTNS reduced proprioceptive error under the hover condition only. Discussion: We argue that nTNS does not disrupt spatial proprioceptive error maps but can improve proprioceptive estimation in the absence of tactile feedback. However, we observe no evidence that nTNS enhances tactileproprioceptive integration as the touch condition does not exhibit significantly reduced error after nTNS. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine the differences between tennis players and untrained peers in the development of upper limb proprioception in 10–15-year-olds. A group of 67 girls (12.75 ± 1.46 years old), including 33 tennis players and 34 age-matched untrained controls, was divided into three age groups: A1, 10–11-years-old; A2, 12–13-years-old; and A3, 14–15-years-old. Joint position sense (JPS) and force sense (FS) were assessed by reproducing memorized target angle or torque value of three joints: glenohumeral, elbow, and radiocarpal. The JPS error for the elbow joint in group A1 was 71% and 80% higher (p < 0.01) than that in groups A2 and A3, respectively, and the performance of all tennis players was 27.5% (p = 0.01) better than that of untrained controls. For FS, proprioception of only the more demanding task tested (reproduction of 50% maximal voluntary contraction) and specific function (elbow and radiocarpal extension, and glenohumeral internal rotation) showed development with age. The error values for elbow extension (A1, A2) and the glenohumeral joint (A3) of tennis players were lower than those of age-matched controls. We conclude that the development of FS in the upper limb varied and was related to the specific functions and joints. The 10–13-year-old tennis players showed elbow extensor FS performance at the level of the older participants, while the 14–15-year-old tennis players were characterized with superior FS internal rotation performance in the glenohumeral joint. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Objective Methods Results Conclusion Temporomandibular dysfunctions (TMDs) have the potential to cause changes in cervical muscle strength, muscle endurance and position sense by changing muscle activation patterns, especially as a result of forward head posture. The effects of TMDs on cervical joint position sense (CJPS) and head posture remain controversial.The aim of this study was to evaluate the head posture and CJPS of individuals with TMDs and compare them with healthy individuals.This research, which was designed as a case‐control study, was concluded with the inclusion of total of 84 participants (42 individuals diagnosed with myogenic TMDs, 42 controls). The assessment of participants included pain severity, neck and jaw functionality and disability, CJPS, head posture and temporomandibular joint (TMJ) range of motion (ROM).Individuals with TMDs exhibited higher angular deviation in CJPS during flexion and extension (p < 0.001). Additionally, individuals with TMDs demonstrated higher TMJ pain, limitation and dysfunction severity, as well as a more limited TMJ ROM (p < 0.001). Head posture was similar between groups (p > 0.05). There is a significant relationship between VAS‐TMJ with VAS‐cervical, FAI, NDI, JFLS‐8 and TMJ ROM (p < 0.05). Moreover, a significant correlation was observed between NDI with FAI and TMJ ROM (p < 0.05).These results indicate that in addition to higher pain severity, disability and lower jaw ROM, CJPS of individuals with TMDs is also negatively affected. Also, parameters related to disability and functionality of cervical and TMJ were significantly correlated. Further studies are needed to determine the factors contributing to these results. [ABSTRACT FROM AUTHOR]

This article from Frontiers in Education introduces students to somatosensation, focusing on elements such as pressure, vibration, light touch, temperature, pain, and proprioception. The lesson includes identifying somatosensory receptors, understanding how information is relayed to the brain, and performing activities to reinforce these concepts. The lesson is designed for 6th to 8th-grade students and aligns with the Next Generation Science Standard MS-LS1-8. The lesson aims to help students understand how sensory receptors respond to stimuli and how the brain processes this information for immediate behavior or memory storage. [Extracted from the article]

Background: Hypertension (HT) is a common chronic disease in older adults. It not only leads to dizziness and other symptoms affecting balance in older adults with HT but also affects the hemodynamics of the cerebral cortex. At present, potential neural mechanisms of balance control in older adults with HT are still unclear. Therefore, this study aimed to explore the differences in the center of pressure (COP) and cerebral cortex activation between older adults with HT and normotension (NT) during standing balance tasks. This study May provide guidance for the early detection of the risk of falls among older adults with HT and the development of clinical rehabilitation strategies. Methods: In this cross-sectional study, 30 older adults with NT (NT group) and 27 older adults with HT (HT group) were subjected to three conditions: task 1, standing with eyes open on a stable surface; task 2, standing with eyes closed on a stable surface; and task 3, standing with eyes open on the surface of the foam pad. Cortical hemodynamic reactions were measured using functional near-infrared spectroscopy, and COP parameters were measured using a force plate. Results: The mean velocity of the COP in the medial-lateral direction in the NT group was significantly higher than that in the HT group (F = 5.955, p = 0.018) during task 3. When proprioception was disturbed, the activation of the left premotor cortex and supplementary motor cortex in the HT group was significantly lower than that in the NT group (F = 14.381, p < 0.001). Conclusion: The standing balance function of older adults with HT does not appear to be worse based on COP parameters than those of older adults with NT. This study revealed that the changes in the central cortex related to standing balance appear to be more indicative of balance control deficits in older adults with HT than changes in peripheral COP parameters, suggesting the importance of the early evaluation of cortical activation in older adults with HT at risk of falls. [ABSTRACT FROM AUTHOR]

To navigate complex environments, walking animals must detect and overcome unexpected perturbations. One technical challenge when investigating adaptive locomotion is measuring behavioral responses to precise perturbations during naturalistic walking; another is that manipulating neural activity in sensorimotor circuits often reduces spontaneous locomotion. To overcome these obstacles, we introduce miniature treadmill systems for coercing locomotion and tracking 3D kinematics of walking Drosophila. By systematically comparing walking in three experimental setups, we show that flies compelled to walk on the linear treadmill have similar stepping kinematics to freely walking flies, while kinematics of tethered walking flies are subtly different. Genetically silencing mechanosensory neurons altered step kinematics of flies walking on the linear treadmill across all speeds. We also discovered that flies can maintain a forward heading on a split-belt treadmill by specifically adapting the step distance of their middle legs. These findings suggest that proprioceptive feedback contributes to leg motor control irrespective of walking speed and that the fly's middle legs play a specialized role in stabilizing locomotion. [Display omitted] • A new actuated treadmill system captures 3D kinematics of flies compelled to walk • Flies walking on the treadmill have similar kinematics to freely walking flies • Proprioceptive feedback is important for leg motor control at all walking speeds • Flies on a split-belt treadmill use their middle legs to counteract perturbations Pratt et al. engineer tiny treadmills that enable 3D tracking of fruit fly walking kinematics. The authors systematically compare treadmills to free and tethered walking, evaluate the role of proprioceptive feedback across walking speeds, and reveal how flies adapt their stepping patterns to maintain course on a split-belt treadmill. [ABSTRACT FROM AUTHOR]

Proprioception from muscle spindles is necessary for motor function executed by the cerebellum. In particular, cerebellar nuclear neurons that receive proprioceptive signals and send projections to the lower brainstem or spinal cord play key roles in motor control. However, little is known about which cerebellar nuclear regions receive orofacial proprioception. Here, we investigated projections to the cerebellar nuclei from the supratrigeminal nucleus (Su5), which conveys the orofacial proprioception arising from jaw-closing muscle spindles (JCMSs). Injections of an anterograde tracer into the Su5 resulted in a large number of labeled axon terminals bilaterally in the dorsolateral hump (IntDL) of the cerebellar interposed nucleus (Int) and the dorsolateral protuberance (MedDL) of the cerebellar medial nucleus. In addition, a moderate number of axon terminals were ipsilaterally labeled in the vestibular group Y nucleus (group Y). We electrophysiologically detected JCMS proprioceptive signals in the IntDL and MedDL. Retrograde tracing analysis confirmed bilateral projections from the Su5 to the IntDL and MedDL. Furthermore, anterograde tracer injections into the external cuneate nucleus (ECu), which receives other proprioceptive input from forelimb/neck muscles, resulted in only a limited number of ipsilaterally labeled terminals, mainly in the dorsomedial crest of the Int and the group Y. Taken together, the Su5 and ECu axons almost separately terminated in the cerebellar nuclei (except for partial overlap in the group Y). These data suggest that orofacial proprioception is differently processed in the cerebellar circuits in comparison to other body-part proprioception, thus contributing to the executive function of orofacial motor control. [ABSTRACT FROM AUTHOR]

Objective: Over the past few years, histopathological studies have demonstrated that the ligamentum mucosum (LM) contains neural and vascular structures. These findings suggest that LM can be used for proprioception and revascularization in the repair of anterior cruciate ligament (ACL). The aim of this study was to evaluate the LM structure in knees with ACL injuries. Methods: The data of patients who underwent knee arthroscopy at our clinic between 2017 and 2022 were retrospectively analyzed. Three groups were included in the study; acute ACL tears (n=89), chronic ACL tears (n=111) and intact ACLs (n=101). The arthroscopic video records of all patients were evaluated retrospectively. LM was defined in three different forms: (1) Intact, (2) ruptured, and (3) non-presence. Results: The non-presence of the LM was significantly more common in chronic ACL tears compared to the other groups (p=0.021), while the presence of the LM (either intact or ruptured) was similar between acute ACL tears and intact ACLs. In acute tears, the number of intact LM was significantly lower than that of intact ACLs (p<0.001). However, it was significantly greater than that of chronic tears (p=0.001). Conclusion: According to the present study, the likelihood of intact LM in chronic ACL tears is quite low. In this regard, we suggest that performing surgery in the acute phase of ACL injury will increase the chances of using the LM as a neurovascular source. In addition, because of the possible effect of the LM on proprioception, we recommend preserving the structure during knee arthroscopy procedures if a healthy LM is present. [ABSTRACT FROM AUTHOR]

Whole body vibration (WBV) is linked to short- and longer-term adverse health outcomes, including cognitive impairment, stress and memory loss, loss of balance, reduced proprioception, visual and vestibular disturbances, gastrointestinal problems, and musculoskeletal disorders. Epidemiological evidence supports the link between WBV and headache and head discomfort, but few experimental studies have examined this relationship, particularly with increased muscle tension, as an intermediary. This study aimed to investigate the relationship between muscle tension and vibration intensity, between perceived neck pain and headache/head discomfort and vibration intensity, and between muscle tension and reported neck pain and headache symptoms from simulated WBV based on field measurements of all-terrain vehicle operation on farm terrain. We observed significantly higher electromyography amplitude in the High condition (equivalent to EU Directive's Exposure Limit Value) compared to both Low (equivalent to EU Directive's Exposure Action Value) and Control (quiet sitting) conditions at the left upper trapezius muscle but there were no significant time effects. Neck pain and headache/head discomfort significantly increased after both Low (91% increase from baseline) and High (154% increase from baseline) vibration conditions but there were no significant differences between conditions. Based on simple regression modeling, the relationship between muscle activity and neck pain or headache was very weak (R 2 = 0–0.093). Given the possibility of multiple factors contributing to headache symptoms, future research should not only consider the role of muscle tension but also sensory conflict, excessive noise, biodynamic responses, and a combination of these factors. [ABSTRACT FROM AUTHOR]

Many organs are designed to move: the heart pumps each second, the gastrointestinal tract squeezes and churns to digest food, and we contract and relax skeletal muscles to move our bodies. Sensory neurons of the peripheral nervous system detect signals from bodily tissues, including the forces generated by these movements, to control physiology. The processing of these internal signals is called interoception, but this is a broad term that includes a wide variety of both chemical and mechanical sensory processes. Mechanical senses are understudied, but rapid progress has been made in the last decade, thanks in part to the discovery of the mechanosensory PIEZO ion channels (Coste et al., 2010). The role of these mechanosensors within the interoceptive nervous system is the focus of this review. In defining the transduction molecules that govern mechanical interoception, we will have a better grasp of how these signals drive physiology. [ABSTRACT FROM AUTHOR]

Proprioception is the "sixth sense" that detects limb postures with motor neurons. It requires a natural integration between the musculoskeletal systems and sensory receptors, which is challenging among modern robots that aim for lightweight, adaptive, and sensitive designs at low costs in mechanical design and algorithmic computation. Here, we present the Soft Polyhedral Network with an embedded vision for physical interactions, capable of adaptive kinesthesia and viscoelastic proprioception by learning kinetic features. This design enables passive adaptations to omni-directional interactions, visually captured by a miniature high-speed motion-tracking system embedded inside for proprioceptive learning. The results show that the soft network can infer real-time 6D forces and torques with accuracies of 0.25/0.24/0.35 N and 0.025/0.034/0.006 Nm in dynamic interactions. We also incorporate viscoelasticity in proprioception during static adaptation by adding a creep and relaxation modifier to refine the predicted results. The proposed soft network combines simplicity in design, omni-adaptation, and proprioceptive sensing with high accuracy, making it a versatile solution for robotics at a low material cost with more than one million use cycles for tasks such as sensitive and competitive grasping and touch-based geometry reconstruction. This study offers new insights into vision-based proprioception for soft robots in adaptive grasping, soft manipulation, and human-robot interaction. [ABSTRACT FROM AUTHOR]

The coherent perceptual experience of one's own body depends on the processing and integration of signals from multiple sensory modalities, including vision, touch, and proprioception. Although nociception provides critical information about damage to the tissues of one's body, little is known about how nociception contributes to own-body perception. A classic experimental approach to investigate the perceptual and neural mechanisms involved in the multisensory experience of one's own body is the rubber hand illusion (RHI). During the RHI, people experience a rubber hand as part of their own body (sense of body ownership) caused by synchronized stroking of the rubber hand in the participant's view and the hidden participant's real hand. We examined whether the RHI can be elicited by visual and "pure" nociceptive stimulation, ie, without tactile costimulation, and if so, whether it follows the basic perceptual rules of the illusion. In 6 separate experiments involving a total of 180 healthy participants, we used a Nd:YAP laser stimulator to specifically target C and Aα fibers in the skin and compared the illusion condition (congruent visuonociceptive stimulation) to control conditions of incongruent visuonociceptive, incongruent visuoproprioceptive, and no nociceptive stimulation. The illusion was quantified through direct (questionnaire) and indirect (proprioceptive drift) behavioral measures. We found that a nociceptive rubber hand illusion (N-RHI) could be elicited and that depended on the spatiotemporal congruence of visuonociceptive signals, consistent with basic principles of multisensory integration. Our results suggest that nociceptive information shapes multisensory bodily awareness and contributes to the sense of body ownership. [ABSTRACT FROM AUTHOR]

Background and Purpose: Individuals post traumatic brain injury (TBI) are likely to experience cognitive, sensory, and motor impairments. Tremor is a common movement disorder that can affect this patient population. The purpose of this case report was to describe the effects that progressive muscle relaxation, meditation, and mental practice-based interventions have on the treatment of chronic right upper extremity tremor in a patient post-TBI. Case Description: A 47-year-old male with a traumatic brain injury presented with a resting and postural tremor of the right wrist flexors and deficits in cognition, sensation, proprioception, balance, and motor function. The patient's primary goal for therapy was to decrease the tremor to improve his quality of life and ability to perform activities of daily living. Methods: Progressive muscle relaxation, breath-focused meditation, and mental practice-based intervention were administered to the patient. Active range of motion activities occurred during weekly in-person sessions and daily practice occurred at home. Results: The patient demonstrated improvements in quality of life, self-ratings of tremor severity, ratings of tremor impact on ADL's, gross motor object manipulation, frequency of tremor via surface electromyography, and visual inspection of a spirograph. Conclusion: A combination of progressive muscle relaxation, meditation, and mental practice-based interventions appeared to positively impact tremor across physical and psychosocial domains in a patient with a chronic tremor. Further investigation is needed to verify these findings. [ABSTRACT FROM AUTHOR]

Background: Although whole-body vibration (WBV) training is acknowledged for its benefits in enhancing motor functions across several neurological disorders, its precise influence on ankle joint proprioception and balance in stroke patients is still not well understood. This research seeks to assess the impact of WBV training on ankle joint proprioception and balance in stroke patients, thereby filling this important research void. Methods: In this prospective cohort study, thirty-five stroke patients were randomly assigned to either the WBV group (n = 17) or a control group (n = 18) using a random number table method. The control group received daily general rehabilitation for four weeks, while the WBV group received an additional 30 min of WBV training each day with the Trunsan S110 Vibration Training System. Blinded outcome assessments were conducted at baseline and post-treatment, utilizing the Berg balance scale (BBS), Functional reach test (FRT), Romberg test length (RTL) and area (RTA), and completion rates of ankle joint dorsiflexion-plantar flexion (DP) and inversion-eversion (IE) tests. Follow-up assessments were performed after four weeks of intervention, focusing on RTL, RTA, DP, and IE as primary outcomes. Results: Analysis of intra-group changes from baseline to post-treatment revealed significant improvements across the BBS, FRT, RTL, RTA, and DP and IE assessments (p < 0.001). Notably, the WBV group showed significant enhancements compared to the control group in DP and IE (p < 0.001 and p < 0.05, respectively), with mean values increasing from 13.556 to 16.765 (23.7%) and from 5.944 to 8.118 (36.6%), respectively. However, WBV did not provide additional benefits over the control treatment for balance recovery parameters such as BBS, FRT, RTL, and RTA (p > 0.05). Conclusions: This study demonstrates that WBV therapy is equally effective as conventional methods in enhancing proprioception and balance in stroke patients, but it does not provide additional benefits for balance recovery. WBV significantly improves proprioceptive functions, particularly in DP and IE parameters. However, it does not surpass traditional rehabilitation methods in terms of balance recovery. These findings indicate that WBV should be incorporated into stroke rehabilitation primarily to enhance proprioception rather than to optimize balance recovery. Trial registration: This study was retrospectively registered in the ISRCTN Registry on 29/07/2024 (https://www.isrctn.com/, ISRCTN64602845). [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate the effects of an 8-week yoga intervention on muscle strength, proprioception, pain, concerns about falling, and quality of life in individuals diagnosed with diabetic neuropathy. Methods: A quasi-experimental design incorporating a pretest-posttest methodology and a control group was implemented in the present study. A total of 30 patients who were diagnosed with type 2 diabetes and neuropathy were recruited and randomly assigned to intervention (n = 15) or non-exercise control (n = 15). Yoga sessions were conducted for a duration of 60 min on three occasions per week, with participants requested to practice at home on other days. Results: The results showed significant main effects of time on the muscle strength (both flexor and extensor muscles, p <.001, ηp2 = 0.652 and p <.001, ηp2 = 0.539, respectively), proprioception error (p <.001, ηp2 = 0.807), pain intensity (p <.001, ηp2 = 0.538), concerns about falling (p <.001, ηp2 = 0.700), and overall score of quality of life (p <.001, ηp2 = 0.475). Moreover, there were significant group-by-time interactions for all variables (p <.001 for all). Conclusion: The study reveals that yoga intervention can be an effective alternative therapeutic approach to medication for individuals with diabetic neuropathy. Yet, future studies are needed on a larger sample size to strengthen the present understanding of the advantageous impact of yoga intervention in this population. [ABSTRACT FROM AUTHOR]

Proprioception plays an important role in both feedforward and feedback processes underlying movement control. This has been shown with individuals who suffered a profound proprioceptive loss and use vision to partially compensate for the sensory loss. The purpose of this study was to specifically examine the role of proprioception in feedback motor responses to visual perturbations by examining voluntary arm movements in an individual with a rare case of selective peripheral deafferentation (GL). We compared her left and right hand movements with those of age-matched female control participants (70.0 years ± 0.2 SEM) during a reaching task. Participants were asked to move their unseen hand, represented by a cursor on the screen, quickly and accurately to reach a visual target. A visual perturbation could be pseudorandomly applied, at movement onset, to either the target position (target jump) or the cursor position (cursor jump). Results showed that despite the continuous visual feedback that was provided, GL produced larger errors in final position accuracy compared to control participants, with her left nondominant hand being more erroneous after a cursor jump. We also found that the proprioceptively-deafferented individual produced less spatially efficient movements than the control group. Overall, these results provide evidence of a heavier reliance on proprioceptive feedback for movements of the nondominant hand relative to the dominant hand, supporting the view of a lateralization of the feedback processes underlying motor control. [ABSTRACT FROM AUTHOR]

Introduction: Rehabilitation after Total Knee Arthroplasty (TKA) often includes proprioceptive exercises to prevent falls, but studies on proprioceptive training have yielded conflicting findings. This study aims to explore impact of proprioceptive training on functional performance after TKA. Methods: Eighty patients who underwent unilateral TKA were randomly assigned to a proprioceptive exercise (PE) group or a routine exercises (RE) group. The PE group received proprioceptive exercises in addition to routine physiotherapy. Osteoarthritis Research Society Internal (OARSI) recommended tests and Oxford Knee Score (OKS) were used to assess performance and outcome at 3 and 6 months. Results: In the 30-s chair sits test, the PE group outperformed the RE group at 3 months (13.69 vs. 9.17) and 6 months (21.07 vs. 18.63) (p < 0.001 and p = 0.030). Stair climbing favoured PE group at 3 months (8.86 vs. 16.66, p = 0.037) and 6 months (0.556 vs. 1.133, p = 0.001). At 6 months in the 40-m fast-paced walk test, the PE group had a significantly shorter time (0.308 min vs. 0.557 min, p < 0.001). Timed up and go test at 6 months favoured PE group (0.204 min vs. 0.377 min). In the 6-min walk test, the PE group covered significantly greater distances than the RE group at 3 months (589.59 vs. 346.53 m, p < 0.001) and 6 months (649.60 vs. 448.32 m, p < 0.001). OKS at 3 months was 38 ± 2.0 for PE group and 38 ± 4 for RE group (p = 1). OKS at 6 months was 42 ± 4 for PE group and 40 ± 2 for RE group (p = 0.94). Conclusion: This study highlights the importance of proprioception-based rehabilitation in improving functional performance for TKA patients, surpassing traditional rehabilitation programmes. [ABSTRACT FROM AUTHOR]

Background: Chronic Ankle Instability (CAI) is a common condition characterized by repeated episodes of ankle "giving way" and impaired balance, leading to functional limitations. Various rehabilitation techniques, including balance training, proprioceptive exercises, whole-body vibration (WBV), and novel approaches like stroboscopic vision, are used to address these deficits. This review evaluates the effectiveness of different rehabilitation interventions for CAI management. Methods: A review was conducted by analyzing 11 randomized controlled trials that investigated the impact of balance and proprioceptive training programs on CAI. The primary outcomes assessed were the Star Excursion Balance Test (SEBT), Cumberland Ankle Instability Tool (CAIT), and Foot and Ankle Ability Measure (FAAM). Methodological quality was assessed using the PEDro scale, and the risk of bias was evaluated with the ROB 2 tool. Results: All rehabilitation interventions demonstrated significant improvements in SEBT, CAIT, and FAAM scores. However, no single intervention was found to be consistently superior. Traditional balance training, strength exercises, BAPS, and WBV all provided meaningful functional gains. Stroboscopic vision training showed similar effectiveness compared to conventional approaches. The evidence supports a combination of balance and strength training for optimal recovery. Conclusions: Balance and proprioceptive exercises are effective in managing CAI, with improvements in both dynamic stability and subjective outcomes. No intervention stands out as the best, but personalized programs incorporating various methods are recommended. Future research should explore the long-term effects and potential synergies of combined interventions. [ABSTRACT FROM AUTHOR]

Incorporating authentic tactile interactions into virtual environments presents a notable challenge for the emerging development of soft robotic metamaterials. In this study, a vision‐based approach is introduced to learning proprioceptive interactions by simultaneously reconstructing the shape and touch of a soft robotic metamaterial (SRM) during physical engagements. The SRM design is optimized to the size of a finger with enhanced adaptability in 3D interactions while incorporating a see‐through viewing field inside, which can be visually captured by a miniature camera underneath to provide a rich set of image features for touch digitization. Employing constrained geometric optimization, the proprioceptive process with aggregated multi‐handles is modeled. This approach facilitates real‐time, precise, and realistic estimations of the finger's mesh deformation within a virtual environment. Herein, a data‐driven learning model is also proposed to estimate touch positions, achieving reliable results with impressive R2 scores of 0.9681, 0.9415, and 0.9541 along the x, y, and z axes. Furthermore, the robust performance of the proposed methods in touch‐based human–cybernetic interfaces and human–robot collaborative grasping is demonstrated. In this study, the door is opened to future applications in touch‐based digital twin interactions through vision‐based soft proprioception. [ABSTRACT FROM AUTHOR]

This paper presents the anatomical and biomechanical aspects of chronic instability of the craniocervical junction (CCJ) with a discussion on clinical diagnostics based on mobility tests and provocative tests related to ligamentous system injuries, as well as radiological criteria for CCJ instability. In addition to the structural instability of the CCJ, the hypothesis of its functional form resulting from cervical proprioceptive system (CPS) damage is discussed. Clinical and neurophysiological studies have shown that functional disorders or organic changes in the CPS cause symptoms similar to those of vestibular system diseases: dizziness, nystagmus, and balance disorders. The underlying cause of the functional form of CCJ instability may be the increased activity of mechanoreceptors, leading to "informational noise" which causes vestibular system disorientation. Due to the disharmony of mutual stimulation and the inhibition of impulses between the centers controlling eye movements, the cerebellum, spinal motoneurons, and the vestibular system, inadequate vestibulospinal and vestibulo-ocular reactions occur, manifesting as postural instability, dizziness, and nystagmus. The hyperactivity of craniocervical mechanoreceptors also leads to disturbances in the reflex regulation of postural muscle tone, manifesting as "general instability". Understanding this form of CCJ instability as a distinct clinical entity is important both diagnostically and therapeutically as it requires different management strategies compared to true instability. Chronic CCJ instability significantly impacts the quality of life (QOL) of affected patients, contributing to chronic pain, psychological distress, and functional impairments. Addressing both structural and functional instability is essential for improving patient outcomes and enhancing their overall QOL. [ABSTRACT FROM AUTHOR]

Background: Motor competence (MC) is a key component reflecting one's ability to execute motor tasks and is an important predictor of physical fitness. For adolescents, understanding the factors affecting MC is pertinent to their development of more sophisticated sporting skills. Previous studies considered the influence of poor proprioceptive ability on MC, however, the relationship between lower limb joint position sense, kinematic control, and MC is not well understood. Therefore, the aim of this study was to determine the relation between joint position sense and kinematic control with MC in adolescents during a lower limb movement reproduction task. Methods: This study was a cross-sectional design. Young people (n = 427, 196 girls and 231 boys) aged 13 to 14 years were recruited. A movement reproduction task was used to assess joint position sense and kinematic control, while the Movement Assessment Battery for Children (mABC-2) was used to assess MC. In this study, participants were categorized into the Typically Developed (TD, n = 231) and Probable Developmental Coordination Disorder (DCD, n = 80) groups for further analysis of joint position sense, kinematic control, and MC between groups. Results: Kinematic data, specifically normalized jerk, showed a significant correlation with MC. There was no correlation between knee joint position sense and MC, and no group differences between DCD and TD were found. Conclusions: Joint position sense should not be used as a measure to distinguish TD and DCD. Rather than joint position sense, control of kinematic movement has a greater influence on the coordination of the lower limbs in adolescents. Movement control training should be implemented in the clinical setting to target kinematic control, rather than focus on joint position sense practice, to improve motor competency. Trial Registration Identifier: NCT03150784. Registered 12 May 2017, https://clinicaltrials.gov/study/NCT03150784. [ABSTRACT FROM AUTHOR]

BACKGROUND: Anterior cruciate ligament rupture is one of the injuries that seriously affect life and sports performance, and the anterior cruciate ligament as a stabilizing structure is irreplaceable in maintaining sports performance. In view of its severe injury manifestations, the current treatment for anterior cruciate ligament rupture is a surgery for anterior cruciate ligament reconstruction. Since an anterior cruciate ligament injury can cause loss of mechanoreceptors, which in turn causes a reduction in proprioception, it is a great problem for patients to recover their motor performance. OBJECTIVE: To summarize the effects of proprioceptive training on clinical outcomes after anterior cruciate ligament reconstruction and to explore the underlying mechanisms, thereby providing more references for clinical prevention and treatment. METHODS: A computerized search of PubMed, CNKI, WanFang Data, and VIP databases was conducted for literature (from January 2013 to March 2023) related to proprioceptive training after anterior cruciate ligament reconstruction that improves joint stability and motor balance ability. A total of 108 articles were finally included for review. RESULTS AND CONCLUSION: Proprioceptive training can effectively improve the proprioceptive functions of patients, such as positional sense and kinesthetic sense after anterior cruciate ligament reconstruction, and improve joint stability, postural control and motor ability. The proprioceptive training improves the proprioceptive function through three mechanisms: stimulation of periprosthetic receptors around the knee joint, activation of spinal reflex stimulation, reinforcement of motor control in the brain, and enhancement of cognitive processing. The proprioceptive training may improve proprioceptive functions by activating the potential mechanisms of growth associated protein-43 activity, Piezo2 mechanotransducer, and NT-3/TrkC signaling pathway. Hydrotherapy is the mainstay in the early stages, while neuromuscular training, individual strength training and visual feedback training are prioritized in the middle and late stages. There exists an as-yet-unsegmented reconstructive surgery graft, sex, and a lack of devices or proprioceptive training methods based on the idea of combining multiple sensory stimuli. [ABSTRACT FROM AUTHOR]

Proprioception can be defined as the ability of an individual to detect motion and position of the various joints in their bodies. Current tools for measuring proprioception lack consensus on their accuracy and validity; they also each have their own limitations, and, furthermore, present barriers to use for clinicians. We propose a new and reliable method for evaluating hip, knee, and ankle proprioception by utilizing a digital inclinometer app to measure joint position sense. The digital inclinometer app recorded the active joint position sense error after each of five trials for the hip and knee joint and ten trials for the ankle joint. To quantify the reliability of the digital inclinometer app, single-measurement and average-measurement intra-class correlation coefficients (ICC) along with the associated 95% confidence intervals (95% CI) were calculated for each joint's position sense error across trials. Both the hip (ICC (2,k) = 0.849 (95% CI = [0.783–0.897])) and knee joint (ICC (2,k) = 0.837 (95% CI = [0.750–0.897])) were found to have moderate to good reliability when the middle three of five trials were analyzed. Unlike the hip and knee, moderate to good reliability for ankle proprioception (ICC (2,k) = 0.785 (95% CI = [0.539–0.893])) was only achieved with the middle eight of ten trials. The results of this study indicate that this digital inclinometer app is able to accurately record joint position sense at the hip, knee, and ankle when the appropriate number of trials are collected; thus, allowing this tool and methodology to be considered for use in both clinical and research environments to measure proprioception, and furthermore, quantify proprioceptive deficits. [ABSTRACT FROM AUTHOR]

Purpose: After stroke, upper limb somatosensation can be impaired which affects motor control. Vision is often used to compensate for this. A clinical assessment which assesses the combined sensorimotor function in the absence of vision would be beneficial in studies targeting sensorimotor improvement. Methods and materials: We adapted the Action Research Arm Test (ARAT) to be performed without vision and called this modified version the sensorimotor ARAT (sARAT). Sixty healthy participants and 22 participants with chronic stroke performed the ARAT, sARAT, Fugl-Meyer upper extremity assessment (FM-UE) and Erasmus modified Nottingham sensory assessment (EmNSA). Discriminative validity of sARAT was evaluated by comparing performance between healthy participants and participants with chronic stroke. Convergent validity was evaluated by correlating sARAT with FM-UE and EmNSA. Results: Participants with stroke performed worse on the sARAT compared to healthy participants (p < 0.001), with median scores of 52 (IQR 32-57) and 57 (IQR 57-57), respectively. The sARAT showed high correlations with FM-UE and EmNSA (r = 0.80-0.90). Conclusions: The sARAT shows good discriminative and convergent validity in people with chronic stroke. It allows a quick assessment of the combined upper limb sensorimotor function, by performing the well-known ARAT with the eyes closed. IMPLICATIONS FOR REHABILITATION: The sensorimotor adaptation of the Action Research Arm Test (sARAT) is a clinical assessment of upper limb activity which is performed with the eyes closed. Combining the gold standard ARAT with the sensorimotor adaptation sARAT can inform about the influence of somatosensory impairments on upper limb activity in stroke survivors when vision is blocked. The sARAT shows good discriminative and convergent validity in persons with chronic stroke. [ABSTRACT FROM AUTHOR]

Proprioceptive impairments occur in approximately 50–64% of people following stroke. While much is known about the grey matter structures underlying proprioception, our understanding of the white matter correlates of proprioceptive impairments is less well developed. It is recognised that behavioural impairments post-stroke are often the result of disconnection between wide-scale brain networks, however the disconnectome associated with proprioception post-stroke is unknown. In the current study, white matter disconnection was assessed in relation to performance on a robotic arm position matching (APM) task. Neuroimaging and robotic assessments of proprioception were collected for 203 stroke survivors, approximately 2-weeks post-stroke. The robotic assessment was performed in a KINARM Exoskeleton robotic device and consisted of a nine-target APM task. First, the relationship between white matter tract lesion load and performance on the APM task was assessed. Next, differences in the disconnectome between participants with and without impairments on the APM task were examined. Greater lesion load to the superior longitudinal fasciculus (SLF II and III), arcuate fasciculus (all segments) and fronto-insular tracts were associated with worse APM task performance. In those with APM task impairments, there was, additionally, disconnection of the posterior corpus callosum, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus and optic radiations. This study highlights an important perisylvian white matter network supporting proprioceptive processing in the human brain. It also identifies white matter tracts, important for relaying proprioceptive information from parietal and frontal brain regions, that are not traditionally considered proprioceptive in nature. [ABSTRACT FROM AUTHOR]

Background: Planning and executing movements requires the integration of different sensory modalities, such as vision and proprioception. However, neurological diseases like stroke can lead to full or partial loss of proprioception, resulting in impaired movements. Recent advances focused on providing additional sensory feedback to patients to compensate for the sensory loss, proving vibrotactile stimulation to be a viable option as it is inexpensive and easy to implement. Here, we test how such vibrotactile information can be integrated with visual signals to estimate the spatial location of a reach target. Methods: We used a center-out reach paradigm with 31 healthy human participants to investigate how artificial vibrotactile stimulation can be integrated with visual-spatial cues indicating target location. Specifically, we provided multisite vibrotactile stimulation to the moving dominant arm using eccentric rotating mass (ERM) motors. As the integration of inputs across multiple sensory modalities becomes especially relevant when one of them is uncertain, we additionally modulated the reliability of visual cues. We then compared the weighing of vibrotactile and visual inputs as a function of visual uncertainty to predictions from the maximum likelihood estimation (MLE) framework to decide if participants achieve quasi-optimal integration. Results: Our results show that participants could estimate target locations based on vibrotactile instructions. After short training, combined visual and vibrotactile cues led to higher hit rates and reduced reach errors when visual cues were uncertain. Additionally, we observed lower reaction times in trials with low visual uncertainty when vibrotactile stimulation was present. Using MLE predictions, we found that integration of vibrotactile and visual cues followed optimal integration when vibrotactile cues required the detection of one or two active motors. However, if estimating the location of a target required discriminating the intensities of two cues, integration violated MLE predictions. Conclusion: We conclude that participants can quickly learn to integrate visual and artificial vibrotactile information. Therefore, using additional vibrotactile stimulation may serve as a promising way to improve rehabilitation or the control of prosthetic devices by patients suffering loss of proprioception. [ABSTRACT FROM AUTHOR]

BACKGROUND: Proprioceptive neuromuscular facilitation (PNF) stretching exercises have been widely advocated for the management of patients with different musculoskeletal conditions. However, its effect on the treatment of temporomandibular dysfunction (TMD) in patients with forward head posture (FHP) has not been fully investigated. OBJECTIVE: To investigate the effect of PNF stretching exercises on the treatment of TMD in patients with FHP. METHODS: A prospective, randomized, double-blinded clinical trial. Twenty-four patients with TMD and FHP aged from 18–40 years were randomly assigned to PNF or control group. The PNF group composed of 12 patients received PNF stretching exercises of masticatory muscles in addition to routine physical therapy treatment (FHP correction exercises and ultrasound for the temporomandibular joint); the control group composed of 12 patients received routine physical therapy treatment only. Interventions were conducted twice a week for six weeks. Craniovertebral angle, pain threshold, pain intensity, temporomandibular joint ROM, and temporomandibular joint function were assessed for all participants before and after the intervention. The outcomes were analyzed using Two-way mixed MANOVA. For further multiple comparisons, post-hoc tests with the Bonferroni correction were performed. RESULTS: There was no significant difference between both groups pre-treatment (p > 0.05). Comparison between groups post-treatment revealed statistically significant differences in all outcome measures (p < 0.05) in favor of the PNF group. CONCLUSION: Adding PNF stretching exercises of masticatory muscles to routine physical therapy programs is an effective method for management of TMD in patients with FHP more than routine physical therapy programs alone. [ABSTRACT FROM AUTHOR]

BACKGROUND: After undergoing fibula-free flap harvest, patients may experience complications such as ankle instability. It remains unclear whether these patients have deficits of proprioception, and the recovery process is also uncertain. OBJECTIVE: This study aimed to objectively evaluate proprioception on the donor and normal side of surgical patients during long-term follow-up using the Pro-kin system. METHODS: This study enrolled 36 patients who underwent reconstruction of the head and neck using osseous free flaps harvested from the fibula. Each patient underwent pre-operative evaluations and was subsequently evaluated at postoperative months 1, 3, 6, and 12. The study assessed the proprioceptive evaluation of the lower limbs, muscle function, range of motion of the ankle, and donor side complications. RESULTS: On the donor side, the average trace error (ATE) at postoperative month 1 was significantly higher than pre-operation, postoperative months 6 and 12 (P < 0.05). The test execution time (TTE) at postoperative month 1 was significantly increased by 9.875s compared to the pre-operative levels (P = 0.012, 95% confidence interval [CI] 4: 1.877–17.873) and by 11.583s compared to postoperative month 12 (P = 0.007, 95% CI: 2.858–20.309). The reduction in range of motion of ankle dorsiflexion was most pronounced at postoperative month 1, exhibiting an 11.25∘ decrease compared to pre-operative levels (P < 0.001, 95% CI: 6.304–16.16). Although the range of motion of ankle dorsiflexion gradually improved over time at postoperative months 3, 6, and 12, it remained lower than pre-operative levels (P < 0.05). CONCLUSION: The study revealed that the patients exhibited proprioceptive disturbances in both lower limbs at postoperative month 1. The proprioceptive function gradually improved over time, with a gradual decrease in donor site complications. [ABSTRACT FROM AUTHOR]

Previous studies have revealed decreased proprioception and perception of joint position in elderly adults. Joint position sense, indicating an individual's ability to perceive the position of limbs without visual aid, is essential for everyday movements. A few studies have shown a positive effect of muscle stretching on joint position sense (JPS). However, these studies have only been conducted with younger participants. The impact of stretching on JPS in elderly adults remains unclear. Therefore, the aim of this study is to compare the acute effects of muscle stretching on joint position sense in young and elderly adults. An experimental group of younger adults (n = 15; 25.4 ± 2.9 years) and an experimental group of active, healthy elderly adults (n = 15; 64 ± 3.5 years) stretched their knee flexor muscles. The absolute error (AE) of the joint position sense was calculated before and after muscle stretching. The results indicated no significant difference in the AE between groups (p > 0.05) after the stretching intervention. The similarity in the physical activity status of the subjects may have influenced the results. Even though no significant age-specific differences were found in this study, its results may not be applicable to non-active elderly adults. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare ankle stability and dynamic single-leg balance between jumping athletes and non-athletes, and to examine the correlation between ankle stability and dynamic single-leg balance. Thirty-eight jumping athletes and thirty-seven non-athletes participated in this study. The Cumberland Ankle Instability Tool (CAIT) was used to assess ankle stability. The Y-Balance Test (YBT) was used to examine single-leg balance in the anterior (AN), posteromedial (PM), and posterolateral (PL) directions. The results show that 42.11% of jumping athletes and 21.62% of non-athletes exhibited chronic ankle instability (CAI) in their examined leg. In addition, jumping athletes exhibited significantly worse ankle stability than non-athletes (p = 0.038). The two groups showed no significant difference in the YBT scores in all directions (p = 0.113 AN, 0.567 PM, 0.542 PL). Very low correlations were found between the CAIT and the YBT scores in all directions (r < 0.107). In conclusion, single-leg jumping athletes experienced a higher prevalence of CAI and significantly worse ankle stability than non-athletes. However, the results of the YBT did not correlate strongly with the CAIT scores, suggesting an inability to predict dynamic single-leg balance deficits based on perceived ankle stability alone in this population. [ABSTRACT FROM AUTHOR]

Total knee arthroplasty (TKA) is a commonly performed surgery aimed at alleviating pain and improving functionality. However, patients often face uncertainties in selecting the timing, location, and type of TKA implant that best meets their needs. This study aims to comprehensively compare various variables, explore trends, and identify factors potentially influencing TKA outcomes. A cohort of 40 TKA subjects received either unilateral posterior stabilized (Persona) TKA or bi-cruciate stabilized (Journey II) TKA. Additionally, 20 healthy controls matched for age, gender, and BMI were included. Participants underwent patient-reported outcome assessments, range of motion evaluations, balance assessments, proprioception tests, and biomechanical analyses. These analyses covered motion, loading, and electromyography during five daily activities and two clinical tests. Multifactor ANOVA was utilized to compare 283 variables and assess their impact on TKA outcomes. A knee biomechanics index was formulated to evaluate deviations from healthy norms. Significant differences were observed in EMG varus/valgus rotation during both ramp-up and ramp-down phases between the two implant groups. Although significant improvements were noted post-TKA for both implants, the results remained below those of the control group. Gender, age, and BMI exhibited noticeable effects on TKA outcomes across several biomechanical variables and demonstrated significant disparities compared to the controls. [ABSTRACT FROM AUTHOR]

The agonist–antagonist myoneural interface (AMI), a surgical method to reinnervate physiologically-relevant proprioceptive feedback for control of limb prostheses, has demonstrated the ability to provide natural afferent sensations for limb amputees when actuating their prostheses. Following AMI surgery, one potential challenge is atrophy of the disused muscles, which would weaken the reinnervation efficacy of AMI. It is well known that electrical muscle stimulus (EMS) can reduce muscle atrophy. In this study, we conducted an animal investigation to explore whether the EMS can significantly improve the electrophysiological performance of AMI. AMI surgery was performed in 14 rats, in which the distal tendons of bilateral solei donors were connected and positioned on the surface of the left biceps femoris. Subsequently, the left tibial nerve and the common peroneus nerve were sutured onto the ends of the connected donor solei. Two stimulation electrodes were affixed onto the ends of the donor solei for EMS delivery. The AMI rats were randomly divided into two groups. One group received the EMS treatment (designated as EMS_on) regularly for eight weeks and another received no EMS (designated as EMS_off). Two physiological parameters, nerve conduction velocity (NCV) and motor unit number, were derived from the electrically evoked compound action potential (CAP) signals to assess the electrophysiological performance of AMI. Our experimental results demonstrated that the reinnervated muscles of the EMS_on group generated higher CAP signals in comparison to the EMS_off group. Both NCV and motor unit number were significantly elevated in the EMS_on group. Moreover, the EMS_on group displayed statistically higher CAP signals on the indirectly activated proprioceptive afferents than the EMS_off group. These findings suggested that EMS treatment would be promising in enhancing the electrophysiological performance and facilitating the reinnervation process of AMI. [ABSTRACT FROM AUTHOR]

Objective: The hand is an extremely unique structure with its own characteristics that should be better understood. To determine the relationship between joint position sense (JPS), hand anthropometrics, and grip strength (GS) in healthy individuals. Methods: Both hands of 50 healthy adults were evaluated. The anthropometric characteristics (AC) were determined using small paper insertion tape. Hand and finger strength were measured using hand dynamometry and a pinchometer, respectively. The wrist JPS was evaluated for wrist flexion, extension, and deviations via a position error test using a goniometer. Results: AC and GS were positively correlated with both the dominant and non-dominant sides in all parameters (p<0.05). There was a significant positive relationship between palmar GS and wrist flexion JPS error on the dominant side (p=0.039, r=0.292) and on the non-dominant side (p=0.033, r=-0.303). There was no significant relationship between JPS and the AC of any other GS parameters (p>0.05). Conclusion: The use of anthropometric data in calculating GS, as well as other complimentary data, can be utilized to determine the type and diversity of exercise for physiotherapy and rehabilitation program organization. The results showed a weak correlation between wrist JPS, AC, and GS. In conclusion, our study showed that AC can be used as an indicator of GS, but GS alone is insufficient to indicate joint position. [ABSTRACT FROM AUTHOR]

Implicit sensorimotor adaptation keeps our movements well calibrated amid changes in the body and environment. We have recently postulated that implicit adaptation is driven by a perceptual error: the difference between the desired and perceived movement outcome. According to this perceptual realignment model, implicit adaptation ceases when the perceived movement outcome—a multimodal percept determined by a prior belief conveying the intended action, the motor command, and feedback from proprioception and vision—is aligned with the desired movement outcome. Here, we examined the role of proprioception in implicit motor adaptation and perceived movement outcome by examining individuals who experience deafferentation (i.e., individuals with impaired proprioception and touch). We used a modified visuomotor rotation task designed to isolate implicit adaptation and probe perceived movement outcomes throughout the experiment. Surprisingly, both implicit adaptation and perceived movement outcome were minimally impacted by chronic deafferentation, posing a challenge to the perceptual realignment model of implicit adaptation. NEW & NOTEWORTHY: We tested six individuals with chronic somatosensory deafferentation on a novel task that isolates implicit sensorimotor adaptation and probes perceived movement outcome. Strikingly, both implicit motor adaptation and perceptual movement outcome were not significantly impacted by chronic deafferentation, posing a challenge for theoretical models of adaptation that involve proprioception. [ABSTRACT FROM AUTHOR]

Visual information affects static postural control, but how it affects dynamic postural control still needs to be fully understood. This study investigated the effect of proprioception weighting, influenced by the presence or absence of visual information, on dynamic posture control during voluntary trunk movements. We recorded trunk movement angle and angular velocity, center of pressure (COP), electromyographic, and electroencephalography signals from 35 healthy young adults performing a standing trunk flexion–extension task under two conditions (Vision and No-Vision). A random forest analysis identified the 10 most important variables for classifying the conditions, followed by a Wilcoxon signed-rank test. The results showed lower maximum forward COP displacement and trunk flexion angle, and faster maximum flexion angular velocity in the No-Vision condition. Additionally, the alpha/beta ratio of the POz during the switch phase was higher in the No-Vision condition. These findings suggest that visual deprivation affects cognitive- and sensory-integration-related brain regions during movement phases, indicating that sensory re-weighting due to visual deprivation impacts motor control. The effects of visual deprivation on motor control may be used for evaluation and therapeutic interventions in the future. [ABSTRACT FROM AUTHOR]

Introduction: Inter-individual variability may contribute to impaired cervicocephalic kinesthetic sensibility (CKS) in patients with nonspecific neck pain. Objectives: To identify subgroups of participants with nonspecific neck pain based on cervical joint position errors (JPEs) and to determine potential factors associated with identified subgroups. Methods: One hundred participants with nonspecific neck pain (unidentified pathoanatomical cause) and 50 controls were recruited. JPEs were measured in cervical extension and rotation, using a laser pointer. JPEs were expressed as absolute (AEs), constant (CEs), and variable (VEs) errors. Clinical characteristics were pain intensity, duration, disability, side of pain, dizziness, psychological features, and range of motion. All tests were performed within 1 day. A cluster analysis was conducted based on AEs. A logistic regression was used to identify factors associated with the cluster groups. Results: Analysis divided neck pain participants into two groups: cluster 1 with greater impaired CKS (n = 36) and cluster 2 with lesser impaired CKS (n = 64). The AEs (all cervical movements) and CE (left rotation) were larger in cluster 1 than 2 (p ≤.002). Overall, participants in clusters 1 and 2 had larger AEs, CEs, and VEs than controls (p ≤.04). The presence of dizziness was a risk factor associated with cluster 1 (OR=2.5, p =.04). The other characteristics were not associated with the cluster groups (p ≥.09). Conclusion: The AEs identified two subgroups of patients with nonspecific neck pain. Participants in subgroup 1 had greater impaired CKS, and participants in subgroup 2 had lesser impaired CKS. Dizziness was a potential risk factor associated with greater impaired CKS. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this study was to determine the normative vestibulo- ocular reflex gain output values of the computerized rotational head impulse test (crHIT) with stationary visual targets (earth bound) in healthy participants in each decade age band of life: 10-19, 20-29, 30-39, 40-49, 50-59, 60-69, and 70+ years. Method: Seventy-seven community-dwelling participants (10-85 years of age) with normal lateral semicircular canal (SCC) functioning and no symptoms or history of vestibular dysfunction were recruited through convenience sampling and assessed with the crHIT using stationary targets. These participants were assessed using two standard protocols in a randomized order. Results: Results from 77 participants (Mage = 46 years; 43 women, 34 men) were analyzed. Pearson's correlation coefficient and simple linear regression indicated a statistically significant relationship between crHIT gain output and age (p >.05) for right gain, 1030°/s², and left gain, 1005°/s². Although a statistically significant relationship was found, the slope was minor, demonstrating that the clinical effect of age on crHIT gain output was insignificant. Furthermore, no statistically significant relationship exists between crHIT gain output and gender (p > .05). Age-dependent normative data were calculated using the 2.5th and 97.5th confidence interval (CI) percentile method. The responses of angular vestibulo-ocular reflex (aVOR) gain values for crHIT are expected to occur within the range for lower limit reference interval (RI) of 0.85-0.9 and upper limit RI of 1.11-1.18 for 1030°/s² and lower limit RI of 0.86-0.92 and upper limit RI of 1.13-1.16 for 1005°/s² .It can be expected that 90% CI of the population with normal lateral SCC function- ing will have aVOR gain values that fall within this range. Conclusion: Despite a statistically significant relationship that exists with aVOR gain output and age, the changes are minor, declining by 0.0088 units per 10 years, justifying the same normative data for all decade age bands. [ABSTRACT FROM AUTHOR]