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In performance testing, it is well-established that general jump types like squat and countermovement jumps have great reliability, but the relationship with volleyball spike jumps is unclear. The objectives of this study were to analyze the relationship between general and spike jumps and to provide improved models for predicting spike jump height by general jump performance. Thirty female and male elite volleyball players performed general and spike jumps in a randomized order. Two AMTI force plates (2000 Hz) and 13 Vicon MX cameras (250 Hz) captured kinematic and kinetic data. Correlation and stepwise-forward regression analyses were conducted at p &lt, 0.05. Simple regression models with general jump height as the only predictor for spike jumps revealed 0.52 ≤ R2 ≤ 0.76 for all general jumps in both sexes (p &lt, 0.05). Alternative models including rate of force development and impulse improved predictions during squat jumps from R2 = 0.76 to R2 = 0.92 (p &lt, 0.05) in females and from R2 = 0.61 to R2 = 0.71 (p &lt, 0.05) in males, and during countermovement jumps with arm swing from R2 = 0.52 to R2 = 0.78 (p &lt, 0.01) in males. The findings include improved prediction models for spike jump height based on general jump performance. The derived formulas can be applied in general jump testing to improve the assessment of sport-specific spike jump performance.

Falls are common in daily life, often caused by trips and slips and, particularly in older adults, with serious consequences. Although arm movements play an important role in balance control, there is limited research into the role of arm movements during balance recovery after tripping in older adults. We investigated how older adults use their arms to recover from a trip and the difference in the effects of arm movements between fallers (n=5) and non-fallers (n=11).Sixteen older males and females (69.7±2.3 years) walked along a walkway and were occasionally tripped over suddenly appearing obstacles. We analysed the first trip using a biomechanical model based on full-body kinematics and force-plate data to calculate whole body orientation during the trip and recovery phase. With this model, we simulated the effects of arm movements at foot-obstacle impact and during trip recovery on body orientation.Apart from an increase in sagittal plane forward body rotation at touchdown in fallers, we found no significant differences between fallers and non-fallers in the effects of arm movements on trip recovery. Like earlier studies in young adults, we found that arm movements during the recovery phase had most favourable effects in the transverse plane: by delaying the transfer of angular momentum of the arms to the body, older adults rotated the tripped side more forward thereby allowing for a larger recovery step. Older adults that are prone to falling might improve their balance recovery after tripping by learning to prolong ongoing arm movements.

The present study examined if elite youth male association football (soccer) players aged 8–19 y (n = 2,875) from the English talent development system, who ultimately achieved professional status differed in stature, body mass, and physical performance (20-m sprint speed, slalom agility speed, vertical counter-movement jump with arm swing jump height, multistage fitness test distance) compared with their non-professional peers. The study also examined the longitudinal pattern of development of stature, body mass, and physical performance, and if this was different between future professionals and non-professionals, while considering the effects of playing position. Multilevel modeling of the 8,898 individual (player-occasion) data points suggested that from age 12.0, the future professionals performed better in a vertical counter-movement jump with arm swing test and slalom agility test than future non-professionals, and improved at a faster rate, so that by age 18.0 the differences in vertical counter-movement jump with arm swing and slalom agility performance were 1.7 cm (p < 0.001, d = 0.3) and 0.14 s (p < 0.001, d = 0.5), respectively. In addition, future professionals were faster (by 0.02–0.04 s on the 20-m sprint, p < 0.001, d = 0.2) and ran further in the multistage fitness test (by 47 m, p = 0.014, d = 0.2) than future non-professionals throughout their development, but there were no differences in stature or body mass during development between the groups. Whereas, multistage fitness test performance improved linearly with age, the development of all other physical characteristics was non-linear. There were inter-individual differences in the development of all characteristics, and there were differences between playing positions in the development of all characteristics. Thus, in summary, future professionals jump higher, are more agile, faster, and more endurance fit than future non-professionals as they age, and the pattern of development is different in professionals and non-professionals for vertical jumping and slalom agility performance.

This research proposes the walking promotion device using arm swing induced by parametric excitation. Generally, the walking is promoted by amplification of arm swing. The proposed device is wearable on wrist such a watch. It consists of weight, link and motor. Moving the weight in the longitudinal direction of the forearm, it occurs parametric excitation. In order to design the link length and weight, the arm and device are modeled and simulated with their parameters. In the result, the weight of the device is set to 0.10kg, the link length of it is set to 0.02 m, and the target amplification angle is decided 1°. To perform a preliminary evaluation experiment, 2-links pendulum was made with following the simulation conditions. Comparing with the states of disabled and enabled the device, the shoulder angle increased 2.23° in average. In addition, an evaluation experiment with human arm was conducted. As the results, the device can increase the arm swing.

Parkinson's disease (PD) is a chronic condition that can be diagnosed and monitored by evaluating changes in the gait and arm movement parameters. In the gait movement, each cycle consists of two phases: stance and swing. Using gait analysis techniques, it is possible to get spatiotemporal variables derived from both phases.In this paper, we compared two techniques: wavelet and peak detection. Previously, the wavelet technique was assessed for the gait phases detection, and peak detection was evaluated for arm swing analysis. These methods were evaluated using a low-cost RGB-D camera as data input source. This comparison could provide a unified and integrated method to analyze gait and arm swing signals.Twenty-five PD patients and 25 age-matched, healthy subjects were included. Mann-Whitney U test was used to compare the continuous variables between groups. Hamming distances and Spearman rank correlation were used to evaluate the agreement between the signals and the spatiotemporal variables obtained by both methods.PD group showed significant reductions in speed (wavelet p = 0.001, peak detection p0.001) and significantly greater swing (wavelet p = 0.003, peak detection p =0.005) and stance times (wavelet p = 0.003, peak detection p =0.004). Hamming distances showed small differences between the signals obtained by both methods (16 to 18 signal points). A very strong correlation (Spearman rho0.8, p0.05) was found between the spatiotemporal variables obtained by each signal processing technique.Wavelet and peak detection techniques showed a high agreement in the signal obtained from gait data. The spatiotemporal variables obtained by both methods showed significant differences between the walking patterns of PD patients and healthy subjects. The peak detection technique can be used for integral motion analysis, providing the identification of the phases in the gait cycle, and arm swing parameters.Clinical Relevance- this establishes that peaks and wavelet techniques are comparable and may use it interchangeably to process signals from the gait of Parkinson's disease patients to support diagnosis and follow up made by a clinical expert.

There are millions of fall-related injuries worldwide requiring medical attention on a yearly basis. These falls place a financial burden on the healthcare system. These falls can occur in the event of disruption in the postural control system and/or a loss of balance while walking. Previously, most gait studies have focused on the assessment of the lower extremities while neglecting the contribution of arm swing as it was believed to be a passive motion. However, it has been shown that there is an active component to arm swing. Moreover, these arm movements have been shown to affect the motion of the center of mass when walking. Therefore, arm swing could mitigate the destabilizing effects of perturbations caused by challenging surfaces. Additionally, no studies have examined the effect of arm swing when walking on a rocky surface. This type of surface causes perturbations in the anteroposterior and mediolateral directions simultaneously, leading to uneven center of mass displacement and spatiotemporal modifications. Hence, the present study assessed the effect of normal arm swing, held arm swing and active arm swing on postural control and dynamic stability when walking on regular and rocky surface. We hypothesized that active arm swing will have a negative impact on postural control and gait dynamics on a regular surface, while rocky surface walking will decrease stability and increase spatiotemporal variability. Additionally, we expect active arm swing to attenuate the negative effects of the rocky surface. Fifteen healthy young adults from the University of Ottawa community (mean age 23.4 ± 2.8 years) were recruited to participate in this study. They were asked to walk using three different arm conditions (normal, held and active arm swing) on the dual-belt CAREN-Extended System (Motek Medical, Amsterdam, NL) on simulated regular and rocky surface. This last is generated using the “Rumble” module (maximum range of ±2 cm at 0.6 Hz vertically, ±1° at 1 Hz pitch, and ±1° at 1.2 Hz roll). Mean, standard deviation and maximal values of trunk linear and angular velocity were calculated in all three planes. Moreover, step length, time and width mean and coefficient of variation as well as margin of stability mean and standard deviation were calculated. A mixed linear model was performed to compare the effects of the arm swing motions and surface types. The arm and surface conditions were set as fixed effects, while the walking speed was set as a covariate. Active arm swing increased trunk linear and angular velocity variability and peak values compared to normal and held arm conditions. Active arm swing also increased participants’ step length and step time, as well as the variability of margin of stability. Similarly, rocky surface walking increased trunk kinematics variability and peak values compared to regular surface walking. Furthermore, rocky surface increased the average step width while reducing the average step time. The spatiotemporal adaptations show the use of “cautious” gait to mitigate the destabilizing effects of both the active arm swing and rocky surface walking and, ultimately, maintain stability.

Introduction: Fall rates in people with Parkinson's Disease range between 35 and 68% with the majority of falls occurring while walking. Initial evidence suggests that when walking without arm swing, people with Parkinson's Disease adapt their stepping foot placement as a means to preserve dynamic stability. However, it remains unexamined what arm swing's effect has on dynamic stability when walking on destabilizing surfaces. Methods: Twenty people with Parkinson's Disease (63.78 ± 8.97 years) walked with restricted and unrestricted arm swing on unperturbed, rocky, rolling-hills, and mediolateral translational surfaces. Data were collected on a split-belt treadmill CAREN Extended-System (Motek Medical, Amsterdam, NL). Bilateral averages and coefficient of variations for step time, length, and width; and mediolateral margin of stability were calculated. Results: Results were examined in three separate analyses that included arm conditions during each of the destabilizing surfaces compared to unperturbed walking (arm-rolling hills, arm-rocky, and arm-mediolateral). Compared to unrestricted arm swing, restricted arm swing reduced average step length (arm-rolling hills) and time (arm-rocky), and increased COV step time (arm-rolling hills). The arm-rolling hills analysis revealed that the most affected leg had a shorter step length than the least affected. The destabilizing surface effects revealed that during the arm-rolling hills and arm-rocky analyses, step time decreased, step width increased, and the COV for step time, length and width increased. No main effects occurred for the arm-mediolateral analysis. Conclusion: Results indicate that foot placement in response to restricted arm swing, in people with Parkinson's Disease, depends on the encountered destabilizing surface. The arm-rolling hills analysis revealed that participants appropriately reduced step length as compensation to their restricted arm swing. However, the arm-rocky analysis revealed that individuals prioritized forward progression over dynamic stability as they decreased average step time. Additionally, the increased spatiotemporal variability in response to the rocky and rolling hills conditions indicate partial foot placement adaptation to maintain an already existing level of global dynamic stability as no changes in the Margin of Stability occurred. Adaptation is further corroborated by the decreased step time and increased step width. These responses reflect attempts to pass the destabilizing terrains faster while increasing their base of support.

In patients with Parkinson&rsquo, s disease (PD), arm swing changes are common, even in the early stages, and these changes are usually evaluated subjectively by an expert. In this article, hypothesize that arm swing changes can be detected using a low-cost, cloud-based, wearable, sensor system that incorporates triaxial accelerometers. The aim of this work is to develop a low-cost, assistive diagnostic tool for use in quantifying the arm swing kinematics of patients with PD. Ten patients with PD and 11 age-matched, healthy subjects are included in the study. Four feature extraction techniques were applied: (i) Asymmetry estimation based on root mean square (RMS) differences between arm movements, (ii) posterior&ndash, anterior phase and cycle regularity through autocorrelation, (iii) tremor energy, established using Fourier transform analysis, and (iv) signal complexity through the fractal dimension by wavelet analysis. The PD group showed significant (p &lt, 0.05) reductions in arm swing RMS values, higher arm swing asymmetry, higher anterior&ndash, posterior phase regularities, greater &ldquo, high energy frequency&rdquo, signals, and higher complexity in their XZ plane signals. Therefore, the novel, portable system provides a reliable means to support clinical practice in PD assessment.

In this paper, we describe and show the results from an affordable integrated system for Parkinson’s disease (PD) diagnostic and follow-up, using RGBD cameras and accelerometers. We validate the system with 26 PD patients and 34 control subjects, in order to analyze the clinical relevance of the system and how both technologies are complimentary in the process of diagnosis and follow-up the progression of the disease.

The symptoms of (PD) often begins on one side of the body before separating bilaterally. Early symptoms of PD are rest tremors, bradykinesia and rigidity. Common signs are a decrease in arm swing, shuffling foot movement and slowness arising from a chair. Rigidity of muscles commonly affects a patient limbs, neck and shoulder PD is currently diagnosed after the neuro degenerative process has started. To optimize and improve PD quality of care, it should be diagnosed early in its onset once symptoms are not yet evident. The current gold standard for patient assessment of PD is the completion of symptom diaries. These diaries are subjective and usually do not accurately reflect what is taking place throughout the day. It is exceedingly difficult for an untrained observer such as family members to provide accurate description of movement characteristic in PD. An alternative way to exercise the abnormal movement in PD is to use a wearable technology system which could aid early detection of the disease and help clinicians manage medication when symptoms fluctuate throughout the day. This paper will evaluate the effectiveness of a wearable multi-sensor kinematic system capable of detecting the tell-tale signs of PD when performing tailored exercise routines. Each exercise routine will examine movement for potential PD symptoms and report finding for deeper clinician analysis.

Locomotion in virtual reality (VR) is one of the biggest problems for large scale adoption of VR applications. Yet, to our knowledge, there are few studies conducted in-the-wild to understand performance metrics and general user preference for different mechanics. In this paper, we present the first steps towards an open framework to create a VR locomotion benchmark. As a viability study, we investigate how well the users move in VR when using three different locomotion mechanics. It was played in over 124 sessions across 10 countries in a period of three weeks. The included prototype locomotion mechanics are arm swing,walk-in-place and trackpad movement. We found that over-all, users performed significantly faster using arm swing and trackpad when compared to walk-in-place. For subjective preference, arm swing was significantly more preferred over the other two methods. Finally for induced sickness, walk-in-place was the overall most sickness-inducing locomotion method.

Introduction: Falling during walking is a common occurrence in people with Parkinson's disease and is closely associated with severe social and medical consequences. Recent evidence demonstrates that arm swing affects dynamic balance in healthy young adults; however, it remains unexamined what its effect is in people with Parkinson's disease, particularly when combined with a secondary dual task. Methods: Twenty people with Parkinson's disease (63.78 ± 8.97) walked with two arm swing conditions (absent and normal) with and without a secondary dual task. Data were collected on a split-belt treadmill CAREN Extended-System (Motek Medical, Amsterdam, NL). Average and standard deviations for trunk linear and angular velocity were calculated along with their instantaneous values (during foot strikes) in all three axes. Averages and coefficient of variations for step length, time, and width; margin of stability; and harmonic ratios were also calculated. Results: Compared with normal arm swing, absent arm swing reduced the least affected leg's average step length and increased its step length coefficient of variation while increasing step time coefficient of variation in the most affected leg. Further, absent arm swing reduced trunk anteroposterior instantaneous angular velocity (least affected leg) and reduced anteroposterior instantaneous linear velocity (bilaterally). For the vertical axis, absent arm swing increased the trunk's average angular velocity but reduced its instantaneous linear velocity and angular velocity standard deviation (least affected leg). Additionally, the margin of stability increased when the arms were absent (least affected leg). Alternatively, dual tasking reduced average step time (most affected leg) and increased the step width coefficient of variation (bilaterally). Additionally, dual tasking increased the mediolateral average angular velocity, instantaneous linear velocity standard deviation (bilaterally), and instantaneous angular velocity standard deviation (least affected leg). For the vertical axis, dual tasking increased average linear and angular velocity standard deviation as well as instantaneous angular velocity standard deviation (bilaterally). Conclusion: Findings suggest that participants attempted to control extraneous trunk movement (due to absent arm swing) through compensatory responses in both lower and upper extremities. However, participants appeared to predominately compensate on their least affected side. Contrastingly, modifying mediolateral foot placement appeared to be the main means of maintaining walking stability while dual tasking.

Bordelon, NM, Jones, DH, Sweeney, KM, Davis, DJ, Critchley, ML, Rochelle, LE, George, AC, and Dai, B. Optimal load magnitude and placement for peak power production in a vertical jump: a segmental contribution analysis. J Strength Cond Res XX(X): 000-000, 2020-Weighted jumps are widely used in power training, however, there are discrepancies regarding which loading optimizes peak jump power. The purpose was to quantify the effects of load magnitudes and placements on the force, velocity, and power production in a countermovement vertical jump. Sixteen male and 15 female subjects performed vertical jumps in 7 conditions: no external load, 10 and 20% dumbbell loads, 10 and 20% vest loads, and 10 and 20% barbell loads with load percentages relative to body weight. Arm swing was encouraged for all, but the barbell load conditions. Kinematics were collected to quantify the whole-body (the person and external loads) forces, velocities, and power as well as segments' contributions to the whole-body forces and velocities. Repeated-measure analyses of variance were performed followed by paired comparisons. Jump heights were the greatest for the no external load and 10% dumbbell conditions. The 10 and 20% dumbbell conditions demonstrated the greatest peak whole-body power, while the 2 barbell conditions showed the lowest peak whole-body power. At the time of peak whole-body power, the 2 dumbbell and 2 vest conditions resulted in greater whole-body forces. Whole-body velocities were the greatest for the no external load and 10% dumbbell conditions. Holding the dumbbells in the hands magnified the effects of external loads in producing forces and velocities. The constraint of arm movements in the barbell conditions limited power production. These findings highlight the importance of load placement and arm swing in identifying the optimal configuration for power production in weighted jumps.

The aims of the study were: a) to analyze the reproducibility of the Modified Agility Test (MAT) according to two types of displacement (i.e. constrained [MATtop] vs. free [MATfree]), b) to examine the explanatory capacity of anthropometric characteristics and neuromuscular performance on the ability to change the direction (CODA), c) to look into the practical consequences of the types of displacement from the perspective of an elite soccer academy. 118 male soccer players (age: 16 (13-25) years old) from the same elite Spanish soccer academy (U13 to senior) were tested twice on two versions of the MAT (MATtop and MATfree), with 48 hours between testing sessions. Moreover, they were tested on linear-sprint performance, over 5 m (S5m) and 15 m (S15m), and the vertical jump (VJ) (countermovement jump with [ACMJ] and without an arm swing [CMJ]). The main findings were: a) the type of displacement did not affect the reliability of the CODA test; b) weight, S15m, ACMJ and CMJ variables explained close to 60% of CODA performance; c) MATtop (i.e. constrained displacement) and MATfree (i.e. free-displacement) CODA tests could show different profiles of development along the age groups; and d) the impact of the task’s constraints was relatively higher in U16 and U17 groups. CODA seems to have a variable meaning depending on the characteristics of the test and the age of the participants.

[Purpose] Arm swing is seldom considered while designing clinical rehabilitation protocols for hemiplegic patients with upper or lower extremity disabilities, likely due to the unclear role that arm swinging plays in the ability to walk. We, therefore, aimed to investigate the effect of arm swinging on walking abilities. [Participants and Methods] The study enrolled 20 healthy adults who performed a 10 m walking test with normal gait, single-arm restricted gait, both-arms restricted gait, and maximum arm-swing gait with one arm fixed in the Wernicke-Mann's position. The walking time, number of steps taken, and pelvic fluctuation were measured for the four gaits. A fixed-trunk type arm sling was used for maintaining the Wernicke-Mann's position. [Results] Velocity and stride length decreased significantly while walking with the single-arm restricted gait and both-arms restricted gait in comparison to normal gait. The maximum arm-swing gait showed no significant differences from normal gait in terms of cadence, velocity, and stride. Pelvic fluctuations also had no significant differences among all gaits. [Conclusion] Restricting movement of one or both arms limited the walking speed and stride; however, in Wernicke-Mann's limb position, if the arm is intentionally swung, the walking speed and stride resembled that of normal gait.

People who work in offices for a long time tend to have poor posture and a decreased range of motion throughout the body. This could lead to chronic neck and shoulder pain if not corrected. Shuai Shou Gong, a version of Arm Swing Exercise (ASE), has been developed and practiced by some Chinese people for over one thousand years to maintain physical well-being. Its beneficial effects on posture and range of motion had not yet been verified. The purpose of this study was to preliminarily examine the immediate effects of ASE on shoulder range of motion (ROM) and occiput-wall distance (OWD) in young adults. The before-after study design was used in fifteen healthy office workers (6 males, 9 females), aged 20-40 years, who participated in the study. The shoulder ROM and OWD of the participants were measured before and immediately after a 10-minute session of supervised ASE. A paired-sample t-test was used to estimate the mean changes in the outcome. Results in this study revealed that shoulder ROM was increased in all directions (P < 0.05) while the OWD was decreased (P < 0.05) after the 10-minute session. However, a postural assessment method using a mobile application (PostureScreen) could not demonstrate a significant improvement. In conclusion, ASE have provided immediate improvements on shoulder ROM and forward head posture as indicated by a decreased OWD. Further research using a randomized controlled trial is needed.

The aim of this study was to investigate the effects of arm motion and surface slope on postural strategies and gait stability. We hypothesized that active arm swing would increase postural control compared to walking with arms held and normal arm swing, and that holding the arms would lead to an increasing number of compensatory gait strategies with the aim of increasing balance, both uphill and downhill. We tested fifteen healthy, young adults (age 23.4 ± 2.8 years) using the Computer- Assisted Rehabilitation ENvironment (CAREN) using a simulated rolling-hills condition under 3 arm swing conditions: held, normal, and active. Outcome measures included spatiotemporal gait parameters and postural stability measures in the 3 planes of motion (anterior-posterior, medial- lateral, and vertical). No significant interaction effects between arm swing and surface slope were found. However, results showed main effect for arms (held, normal, active) and slope (uphill versus level walking, downhill versus level walking) conditions. Stepping and postural strategies when walking uphill compared to level were opposite to those used in downhill walking compared to level. Participants adopted an overall more cautious strategy when walking downhill, as seen by a combination of decreased cadence and increased double-support time, while the opposite strategies were seen in uphill walking. Effects of arm swing remained relatively consistent for both uphill and downhill walking conditions. Both uphill and downhill, holding the arms led to stability-seeking measures in the form of increasing base of support (double-support time), and increased control (decreased vertical accelerations of the head and trunk compared to normal and active arm swing). These results substantiate the destabilizing effects of walking without arm swing and the usefulness of active arm swing for enhancing gait stability on minor slopes. This research also provides insight into the control mechanisms regulating dynamic balance in healthy young adults, which can be used to inform protocols and develop models aimed at preventing occupational health and safety hazards in challenging environments (e.g. construction workers).

Humans often perform tasks that require them to carry loads, but the metabolic cost of carrying loads depends on where the loads are positioned on the body. We reasoned that carrying loads at the arms’ center of mass (COM) during walking might be cheap since arm swing is thought to be dominated by passive pendulum dynamics. In contrast, we expected that carrying loads at the leg's COM would be relatively expensive because muscular actuation is necessary to initiate and propagate leg swing. Therefore, we hypothesized that carrying loads at the arm's COM while swinging would be cheaper than carrying loads at the leg's COM. We further hypothesized that carrying loads at the arm's COM while swinging would be more expensive than carrying loads at the waist, where the mass does not swing relative to the body. We measured net metabolic power, arm and leg motion, and the free vertical moment while subjects (n=12) walked on a treadmill (1.25 m/s) with no-load, and with 8-kg added to the arms (swinging vs. not swinging), legs, or waist. We found that carrying loads on the arms or legs altered arm swinging amplitude; however, the free vertical moment remained similar across conditions. Most notably, the cost of carrying loads on the swinging arms was 9% less than carrying at the leg's COM (P

Das Armpendel ist ein wesentlicher Bestandteil der menschlichen Fortbewegung. Bei Ver-letzungen im Schulterbereich ist die Immobilisation des Schultergelenks meist Teil des Be-handlungskonzepts. Durch eine solche Immobilisation ist in der Folge das Armpendel ein-seitig eingeschränkt, was weitere Auswirkungen auf messbare Gangparameter haben kann. Vor diesem Hintergrund ist es Ziel dieser experimentellen Pilotstudie den Einfluss des, durch eine orthopädische Orthese einseitig eingeschränkten Armes auf die spatio-temporalen Gangparameter zu untersuchen. Dies soll weiteren Aufschluss über den Stel-lenwert des Armpendels und dessen klinischen Einfluss auf Gangsicherheit und Gangstabi-lität geben. Weiterführend zielt diese Pilotstudie darauf ab, die angewandte Methodik an-hand einer kleinen Stichprobe (n=10) zu testen. Mittels OPTOGait Messsystems wurden Daten für Geschwindigkeit, Schrittlänge, Standphase und Single Support Phase als primä-re Outcome Parameter generiert. Durch den t-Test für abhängige Stichproben konnten kei-ne statistisch signifikanten Verminderungen in Gehgeschwindigkeit, Schrittlänge oder Sin-gle Support Phase erkannt werden. Ebenso zeigen die Ergebnisse keine statistisch signifi-kanten Asymmetrien in Schrittlänge und Standphase während der Armpendelrestriktion durch den Gilchrist-Verband. Weitere Untersuchungen mit repräsentativen Stichproben sind jedoch notwendig, um generell gültige Aussagen über den Einfluss einer orthopädi-schen Armrestriktion auf den menschlichen Gang treffen zu können. The arm swing is an essential part of bipedal human locomotion. In the case of shoulder injuries the immobilization of the shoulder joint is commonly used as part of the treatment plan. Due to this immobilization the natural occurring arm swing is restricted on the affected side. This can have further impact on measurable gait parameters in otherwise healthy pa-tients. In context, this experimental pilot studies purpose is to investigate the influence of the unilateral restriction of the dominant arm by an orthopaedic orthosis on the spatio-temporal gait parameters. This aims to provide further information about the significance of the arm swing on gait and its clinical influence on gait safety and gait stability. Furthermore, this pilot study is designed to test the applied methodology on a small sample (n=10). The OPTOGait measurement system was used to generate data for speed, stride length, stance phase and single support phase as primary outcome parameters. Using the t-test for de-pendent samples, no statistically significant reductions in walking speed, stride length or single support phase could be detected. Likewise, the results do not show statistically sig-nificant asymmetries in stride length and stance phase during arm pendulum restriction by the gilchrist sling. However, further studies with representative samples are necessary to make generally valid statements upon the impact of arm swing restriction using an ortho-paedic restriction on human locomotion.

Jump performance provides meaningful information both for sporting and clinical needs. Current state-of-the-art in jump performance assessment is laboratory-bound, however, out-of-the-laboratory methods are desirable. Therefore, the purposes of the present investigation were 1) to explore whether utilising a novel analytical approach minimises the bias between inertial recording unit (IMU)-based and jump mat-based jump height estimates, and 2) to provide a thorough tutorial for a sport scientist (see appendix) to facilitate standardisation of jump height estimation. Forty one women, men and boys aged 6 to 77 years-of-age completed three maximal counter movement jumps without arm swing, which were concurrently registered with a jump mat, and an IMU worn in low lumbar region. Excellent agreement between the novel IMU-based jump height and jump mat jump height was observed (mean IMU 22.6 [8.3] cm, mean jump mat 22.7 [8.9], mean bias -0.1 cm [95% limits of agreement -4.5 cm to 4.4 cm; p = 0.826], intra-class correlation coefficient 0.97 [95% CI 0.94 to 0.98, p < 0.001]). In conclusion, inertial recordings conducted with lightweight IMUs worn on the hip provide a valid and feasible assessment of jump height among people with varying athletic ability. Inertial signals have the potential to afford (at least semi-) automated analysis pipeline with low labour cost thus being potentially feasible in applied settings such as in professional sports or in the clinics. peerReviewed

Recently, motion analysis really helps athletes improve their performance. Since the systems of motion analysis are expensive and expertise in biomechanics or kinematics is necessary, it is difficult for athletes themselves to use them. In this work, we propose a motion analysis system with acceleration sensor. The proposed system is inexpensive since the system consists of inexpensive components. Besides, only two devices for analysis are required by concentrating on analyzing the motions of arm swing and foot strike. Experimental results demonstrate that the proposed system is useful for athletes to analyze running form.

Background Arm swing changes are common even in the early stages of Parkinson's disease (PD). We hypothesized that arm swing changes decrease with age and can be detected using a low-cost, RGB-D depth-sensing camera. Objective This study aimed to assess the differences in arm swing between PD patients and healthy participants and to investigate the possible effects of aging on these differences. Methods Twenty-five PD patients (aged 45-87 years) and 25 age-matched, healthy subjects (aged 46-88 years) were included. Clinical variables were evaluated using a descriptive analysis. No spatiotemporal variables were normally distributed; therefore, we used a Mann-Whitney U test to compare the continuous variables between groups and to perform age-stratified analysis. A receiver operating characteristic analysis was generated to evaluate the discrimination activity of arm swing asymmetry (ASA). Results The PD group showed significant reductions in arm swing magnitude (left, p = 0.002; right, p = 0.006) and arm swing speed (left, p = 0.002; right, p = 0.004) and significantly greater ASA (p 67 years. Conclusions The camera detected differences in ASA, arm swing speed, and arm swing magnitude between PD patients and healthy individuals. Analysis of arm swing variables should be stratified by age, and the validity of the analysis may be questionable in patients aged >67 years.

Surface electromyography (sEMG) is widely used to analyze human movements, including athletic performance. For baseball pitchers, a very precise movement is required to pitch the ball into the strike zone. The palm muscles appear to play a key role in this movement, and a real-time recording of sEMG from the palm muscle is useful in the analysis of motion during baseball pitching. However, the currently available devices with rigid and bulky electrodes (including connective wires) impede natural movements of the wearer and recording of sEMG from the palm muscles during vigorous action. Here, we describe a skin-contact patch consisting of kirigami-based stretchable wirings and conductive polymer nanosheet-based ultraconformable bioelectrodes, which address the challenge of mechanical mismatch between human skin and electrical devices. The key strategy is a kirigami-inspired wiring design and a mechanical gradient structure from nanosheet-based flexible bioelectrodes to a bulk wearable device. This approach would buffer the mechanical stress applied to the skin-contact bioelectrodes during an arm swing movement. With this patch, we precisely measure sEMG at the abductor pollicis brevis muscle (APBM) in a baseball player during ball pitching. We observe differences in the activity of the APBM between different types of pitches—fastball and curveball. This sEMG measurement system will enable the analysis of motion in unexplored muscle areas, such as on the palm and the sole, leading to a deeper understanding of muscular activity during performance in a wide range of sports and other movements. A skin-contact patch that uses kirigami-inspired techniques to avoid mechanical stress can provide insights into hard-to-capture palm muscle movements. Conventional electromyography (EMG) instruments that measure a muscle’s electrical signals are too bulky to be worn during athletic actions such as baseball pitching. Japanese researchers led by Tomoyuki Nagami from Kitasato University College in Kanagawa and Toshinori Fujie from Waseda University in Tokyo have used ‘kirigami’ — a version of origami that involves cutting and folding — to produce lightweight and stretchable wires that can run from polymeric ultrathin film electrodes attached to a volunteer’s palm muscle to a Bluetooth transponder fixed on the forearm. Wireless recording of EMG during the throwing motions of an experienced baseball pitcher revealed that there was a difference in the timing of palm muscle activity between fastball and curveball. Surface electromyography (sEMG) is widely used to analyze human movements, including athletic performance. Here, we develop a skin-contact patch consisting of kirigami-based stretchable wirings and conductive polymer nanosheet-based ultraconformable bioelectrodes that can detect sEMG signals from the palm muscle during baseball pitching. We observe differences in the activity of the palm muscle between different types of pitches—fastball and curveball. This sEMG measurement system will enable the analysis of motion in unexplored muscle areas, leading to a deeper understanding of muscular activity during performance in a wide range of sports and other movements.

Previous studies have investigated how additional arm weights affect gait. Although light weights (0.45 kg) seemed to elicit performance improvements in Parkinsonian patients, it was not studied how light weights affect gait parameters in healthy individuals. It is important to understand normal responses in a healthy population so that clinical effects might be better understood. Therefore, the purpose of this study was to investigate the effects of arm weights on arm swing amplitude, gait performance, and muscle activity in healthy people. Twenty-two subjects walked overground at their preferred speed under different weight carriage conditions (C1: no weight; C2: unilateral arm weight; C3: bilateral arm weights; C4: waist weights). Gait speed increased in C2 (p = 0.018) and C4 (p = 0.013) when compared with C1(C1: 1.21 ± 0.08; C2: 1.25 ± 0.11; C3: 1.24 ± 0.11; C4: 1.25 ± 0.11 m/s) with an increase in cadence during C2 (p 0.001), C3 (p = 0.008), and C4 (p 0.001) (C1: 105.5 ± 5.2; C2: 108.5 ± 5.6; C3: 107.9 ± 5.6; C4: 108.5 ± 5.3 steps/min) and in tibialis anterior electromyographic activity on the unweighted side in C2 (p = 0.048) (C1: 21.05 ± 4.59; C2: 25.10 ± 6.10; C3: 23.93 ± 4.75; C4: 24.33 ± 6.32 μV). The results indicate that an additional sensory input with the application of the weights may result in an overcompensation with the whole body and facilitate faster walking speed when applied on one arm or around the waist. The locations of the weights and amount of the weights may elicit different responses. Various strategies of adding weights should be further investigated as a potential intervention to improve performance in individuals with various gait impairments. Although there is evidence for benefits of this intervention in Parkinsonian patients, further study is warranted in other patient populations, such as stroke patients, who might benefit from this intervention to improve gait performance.

The aim of the study was to analyze the effect of knee compression bandage and arm swing control on the maximum horizontal distance and ground reaction force variables in standing long jump. Adult male (n=8; mean age, 22.75±1.98 years; mean heights, 1.77±0.03 m; mean weights, 71.82±12.87 kg) participated in the experiment. The results obtained from variables of ground reaction force (GRF) in medial lateral, anterior posterior (AP), vertical (V) direction, resultant GRF (RGRF), decay rate (%), and maximum horizontal distance (MHD) were as follows; MHD, AP GRF, VGRF, RGRF (AP-V), and ratio of load reduction (%) showed more effective result under both wearing of knee compression bandage and arm swing. In analysis of main effects, MHD, AP GRF, VGRF, and RGRF showed more increased value in case of wearing of knee compression bandage than as was not. While arm swing during standing long jump (SLJ) works as important factor to MHD, showed more effective factor in exercise rehabilitation, injury prevention and swell treatment etc. in wearing of worn knee compression bandage. Therefore it was assumed that arm swing and wearing of knee compression bandage may improve the performance of SLJ. Also, the characteristics of knee compression bandage suggest that it can be a great help for those participating in exercise rehabilitation.

This study aimed to identify the effects of rhythmic arm swing during robot-assisted walking training on balance, gait, motor function, and activities of daily living among patients with subacute stroke. Twenty patients with subacute stroke were recruited, and thereafter randomly allocated to either the experimental group that performed the robot-assisted walking training with rhythmic arm swing, or the control group that performed the training in arm fixation. In total, 30 training sessions were carried out. The outcome measures included the 10-m walk test, Berg balance scale, timed up-and-go test, fall index that was measured using the Tetrax system, motor function test of Fugl-Meyer assessment, and modified Barthel index. The patients of both groups showed significant improvement in all parameters after the intervention (P

OBJECTIVE: This experimental research design randomized two groups pre- andpost- test, aimed at examining the effects of arm swing exercise program on hemoglobinA1c (HbA1c) and nutritional status in adults with type 2 diabetes mellitus (T2DM) MATERIAL AND METHODS: Participants from Sub-district Health PromotingHospital were randomly divided into two groups: an experimental group with 22participants receiving arm swing exercise program for 12 weeks and a control groupwith 21 participants receiving routine nursing care. Data collection was done beforeand after the intervention using a demographic and a perceived self-efficacy in exercisequestionnaire, HbA1c, waist circumference and body mass index (BMI). The data wereanalyzed by using descriptive statistics, Paired t-test and Independent t-test. RESULTS: The findings showed that after the arm swing exercise program, theexperimental group had significantly lower average of HbA1c, waist circumference andBMI compared with before the program (p = 0.010, p = 0.000, p = 0.003, respectively).The experimental group also had lower average of HbA1c compared with the controlgroup (p = 0.013), but waist circumference and BMI were not significant. CONCLUSION: The arm swing exercise program should be applied to adults withT2DM to control diabetes and its complications. Keywords: arm swing exercise program, HbA1c, waist circumference, body mass index, adults with type 2 diabetes

Normal walking includes coordinated and controlled movement of the legs and arms. However, patients following stroke often present with inappropriate motor control which limits coordinated movement patterns of the affected limbs. This study aimed to compare the effects of rhythmic arm swing and arm fixation during treadmill walking in patients with poststroke hemiparesis. We used an alternating study design with multiple baselines across subjects. Three patients with chronic stroke participated in this study. During treadmill walking, rhythmic arm swing and arm fixation conditions were alternately applied. Outcome measures included the 10-meter walk test (10MWT) and energy expenditure index (EEI). In the intervention phase, all subjects showed significantly greater improvements in the 10MWT and EEI scores for rhythmic arm swing condition compared to those for arm fixation condition (p 0.05). 10MWT improvement rates: Subject 1-34.81% vs. 15.75%; Subject 2-40.00% vs. 17.95%; and Subject 3-38.08% vs. 21.85%; and EEI improvements: Subject 1-23.19% vs. 14.08%; Subject 2-26.15% vs. 20.43%; and Subject 3-22.99% vs. 14.49%. These findings suggest that rhythmic arm swing is clinically feasible as a more favorable option to enhance the effects of treadmill walking training. However, larger studies with a different study design are needed to be able to make any judgment about the usefulness of the treatment.

[Purpose] Interlimb coordination can be affected by the symptoms associated with Parkinson’s disease and may result in an increased risk of falls. The purpose of the current study was to compare changes in interlimb coordination in individuals with Parkinson’s disease to healthy older adults while systematically manipulating walking speed. [Subjects and Methods] Participants walked on a treadmill while systematically increasing and decreasing the walking speed between 0.22 and 1.30 m/s. Kinematic data were collected by means of a three dimensional motion capture system. Dependent variables included the phase relation between arm and leg movements as well as between pelvic and thoracic rotation. [Results] Compared to healthy controls, an increased variability in relative phase between left and right arm swing, and smaller amplitude with arm, leg as well as less variability for the phase relation between thoracic and pelvic rotations were shown in individuals with Parkinson’s disease. [Conclusion] The increased variability of phase relation between left and right arm swing may be related to the reduced out-of-phase forcing of the arm movements at the shoulders as a result of axial rigidity in Parkinson’s disease. It deserves further investigation whether the improvement of the coordination between arms could result in the normalization of parkinsonian gait.

The purpose of this pilot study was to assess the accuracy of steps and heart rate measurement of wrist fitness trackers at different prices. Four healthy college students voluntarily tested three wrist fitness bands and a sports watch (Xiaomi Mi Band, Fitbit Charge HRm, Fitbit Surge, and sports watch Polar M400). Subjects performed two sets of 10 series of 100 steps wearing the fitness trackers on an indoor track in two situations: walking and jogging. In the walking situation, the subjects wore a winter coat and gloves. The variables measured were the number of steps, the heart rate, and the level of error. The steps error percentage for all four devices was lower than 8%. The Fitbit Surge registered significantly more steps in the walking situation (p < 0.001). No significant differences were found in the steps measurements in the jogging situation (p = 0.138). In the jogging situation, significantly lower values in the heart rate measurements for the Xiaomi Mi Band, Fitbit Charger HR, and Fitbit Surge were found (p < 0.001). The results showed that the wearable fitness trackers were relatively accurate for tracking steps (on average, there was a level of error of 2–6%). The assessment of the steps was more accurate in the jogging situation (higher and faster arm swing) than in the walking situation, which involved wearing coats and gloves. The results showed that the wearable fitness trackers that were tested underestimate the heart rate with a level of error of approximately 6–11%. The step error was lower in the walking situation (less mobility of the devices). The price of the devices that were tested did not affect the accuracy of the steps and heart rate assessment. Further studies with a larger sample and more type of devices are needed to confirm these results.

[Purpose] The gait characteristics, such as short step, decreased arm swing and stooped posture, in Parkinson disease (PD) are well established. Pharmacological and non-pharmacological treatments have been attempted to improve the gait in patients with PD. Among the non-pharmacological approaches to improve gait, spinal orthosis can be applied for patients with spinal deformity. The purpose of our study was to investigate the effect of spinal kypho-orthosis to gait in PD by using a three-dimensional analysis. [Participants and Methods] Twenty-six patients with PD with gait disturbance with forward bend posture >15°. All participants were instructed to walk along a 6-m track and turn 180° and come back to the starting point under three-dimensional motion capture. The participants performed the test again with spinal kypho-orthosis. Gait parameters during examination is compared with and without spinal kypho-orthosis. The degree of forward flexion after kypho-orthosis in patients with PD was compared. [Results] Wearing the spinal kypho-orthosis significantly improved turning performance but did not affect locomotion. The severity of forward bend posture is mildly improved after the application of spinal kypho-orthosis. [Conclusion] Spinal kypho-orthosis has a short-term effect for gait performance, particularly during turning and erect posture. Spinal kypho-orthosis can be potentially used for management of turning deficits in PD.

Previous studies have examined the role of arm swing for various types of jumping technique, but none have been found to study about the gender differences in term of the role of arm swing on forward and backward jump. This study aimed to compare the jumping performance between male and female for forward and backward jump. Seven male and seven female subjects performed four trials of forward and backward jump with (FJA, BJA) and without arm swing (FJ, BJ) respectively. Qualisys Track Manager System, EEGO Sports, Visual3D and MATLAB software was used to record and analyze the performance. According to the result, the triceps brachii muscle is the most active muscle compared to other muscles during jumping. The normalized vGRF showed significant correlation with jump height when jumping forward and backward (p