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Patellar tendinopathy is a common injury characterized by progressive activity-related anterior knee pain. It is highly prevalent in sports which involve jumping and changing direction. The aim of this paper is to review recent high-quality evidence regarding the effectiveness of physical therapy in the treatment of patellar tendinopathy. Randomized controlled trials (n = 22) researching the effects of exercise therapy, physical agents, and soft tissue techniques were included. The results show that exercise therapy is the most effective. While eccentric exercise is commonly used, very promising progressive tendon-loading exercise therapy programs are recently emerging. Extracorporeal shock wave therapy, dry needling, and orthoses are no more effective than eccentric exercises or placebo groups. Isometric and isotonic exercise, patellar strap, sports tape, and kinesiotaping have a short-term effect on functional improvement and pain reduction, while progressive tendon-loading exercise, dry needling, platelet-rich plasma, and extracorporeal shock wave therapy have long-term effects.

Objectives: The aim of this study was to analyze Slovenian data on sick leave (SL) due to the most common work-related musculoskeletal disorders (MSDs) among workers in sector I “accommodation and food services activities” from the NACE Rev2 classification. Methods: We investigated both SL incidence (i.e., number of cases) and disease severity (i.e., average SL duration) by body site, gender, age and divisions within the sector. In addition, trends in SL data (difference between 2015 and 2019) were analyzed. The effect of age group, gender and division was also assessed with relative risk (RR). RESULTS: Female gender was associated with higher risk of MSDs in young (RR = 1.91 (1.53–2.43)) and older (RR = 2.24 (1.90–2.65)) subgroups. Older age was associated with greater SL incidence and longer SL duration, regardless of gender and division within sector I. This was also reflected in relative risk calculations between older and younger groups (females: RR = 4.43; CI = 3.75–5.01;p< 0.001; males: RR = 3.71; CI = 2.89–4.77;p< 0.001). Low back disorders were the most frequent cause for SL, while lower limb disorders tended to cause the longest average SL. The SL durations were similar across divisions within the sector, while the incidence rate tended to be higher in the “accommodation” than the “food and beverage services” division. Conclusions: Special attention needs to be paid to reducing the risk of low back disorders, which are by far the most common cause of SL, and lower limb disorders, which cause the longest SL. We recommend the implementation of countermeasures that focus on early detection and rapid treatment/recovery of MSDs in older workers.

Background Postural sway during quiet standing has been shown as a useful task to assess risk of falling in older adults. While the risk of falling is consistently reported to be higher in older females than males, the sex-related differences in postural sway are not consistent across the studies. Research question What are the effects of age and sex on postural sway during quiet standing during different stance conditions? Methods We examined the effects of age (40 young and 34 older adults), sex (37 males and 37 females), and their interaction on the postural sway during different stance conditions. We compared the center of pressure (CoP) velocity, amplitude and frequency during parallel (eyes open and eyes closed) and semi-tandem (eyes open) stances. Results Our results suggest that postural sway is similar between sexes in young participants, while older males exhibit larger postural sway than older female participants (10/21 outcomes). Older female participants exhibited lower CoP amplitude (but larger total and anterior-posterior CoP velocity) compared to young female participants. We also found that the increase in the postural sway with increasing task difficulty is more pronounced in older vs. young adults. Significance This study shows that ageing-related changes in postural sway are sex- and task-specific. Researchers and clinicians need to be aware of these effects when comparing groups or monitoring changes in time.

The aim of this study was to investigate the reliability of running biomechanics assessment with a wearable commercial sensor (RunScribe

Countermovement jump (CMJ) is frequently used to assess the neuromuscular capacity in athletes and track adaptations to training, typically through outcome variables such as jump height, peak/mean force, power or velocity, and rate of force development. Recently, there has been an increasing interest to analyze the shape of the force-time curve of the CMJ and its relationship to CMJ performance. This aim of the present review was to collect and analyze the available literature pertaining to this topic. One approach to analyze CMJ curve shape is to classify it as "unimodal" or "bimodal," based on the number of force peaks. The difference between athletes showing unimodal and bimodal curves is negligible in terms of jump height, while unimodal curves are associated with higher reactive strength index. Rather than the number of peaks, the most important characteristics that maximizes CMJ height seems to be the temporal alignment of peak force with the instant of the lowest center-of-mass position (i.e., when the jumper transitions from the braking to the propulsive phase). Other than bimodal/unimodal classification, the "shape factor" (the value of force impulse, divided by the area of the rectangular shape drawn around) has been emerging as another approach to assess CMJ curve shape; however, the studies exploring its relationship with performance are few and inconclusive.

Diastasis recti abdominis (DRA) is a common occurrence in postpartum women, and it is unclear what types of nonsurgical interventions are most effective in preventing and/or reducing it. The aim of this review with meta-analysis was to investigate which conservative treatment approaches are the most effective for the management of postpartum DRA. After a thorough search of the PubMed and Scopus databases, we reviewed 14 articles. The literature suggests that abdominal exercise programs are generally effective in treating DRA at various postpartum periods. There is preliminary but promising evidence of the efficacy of electrical stimulation in combination with exercise. In addition, abdominal kinesiotaping can be used in conjunction with other interventions. Limitations of previous research include (a) the use of different measurement methods (palpation, calipers, ultrasound) and sites, (b) the evaluation of treatment effects in different time periods, and (c) the use of a wider range of exercise combinations. Although abdominal exercise is a cornerstone of DRA treatment, the optimal exercise combination is currently unknown due to these limitations.

The effectiveness of eccentric exercise interventions (EEI) has been extensively explored in different populations. The aim of our umbrella review was to combine all systematic reviews about the chronic efficiency of EEI and to summarize the literature on the chronic effects of different types of eccentric exercise protocols, with or without extra loads and devices (e.g., Flywheel device), compared to other therapeutic interventions, exercise interventions, or no intervention. We screened four major electronic scientific databases (PubMed, Scopus, Web of Science, and PEDro), using one combined string for all included databases (eccentric exercise OR flywheel OR isoinertial exercise OR eccentric training). Included reviews needed to be based on any human population, that executed EEI in comparison with any other type of intervention. The methodological quality of the included reviews was assessed using AMSTAR 2 tool. Considering the inclusion criteria, we included 35 reviews. EEI were found suitable for chronic or long-term pain reduction in patient populations. EEI largely improved muscle performance (muscle strength, and muscle power), muscle architecture (e.g., pennation angle, fascicle length, cross-sectional area, muscle thickness, and muscle mass), decreased risk of injury, incidence, and severity of the injury, and increased range of motion of the joints There is less evidence about the effects of EEI in older adult populations, compared to athletes and younger populations, however, eccentric exercise seems promising for these populations as well.

Objective:Previous research suggests that muscle strength exercise is the most effective rehabilitation methods in patients with patellofemoral pain (PFP). This systematic review with meta-analysis compared the effects of Hip&Knee, Hip-only and Knee-only exercise programs on pain relief, muscle strength, and functional performance in patients with PFP. Methods:Literature searches of PubMed, PEDro and CINAHL databases revealed twenty-one studies included in the final descriptive review, thirteen of which were included in the meta-analysis. Data extraction included baseline and post-intervention means and standard deviations of all eligible outcome measures both for the intervention and control groups, participants baseline demographics and intervention characteristics. Results:The results showed that Hip&Knee and Hip-only exercise programs were comparatively effective, while the Knee-only exercise programs proved to be inferior to the above-mentioned approaches. The Hip&Knee exercise programs showed the greatest pain relief (mean difference = − 1.71 (− 3.11, − 0.30); p = 0.02; I2= 96%) and functional improvement (standardized mean difference = 1.28 (0.45, 2.12); p = 0.003; I2= 84%), although the subgroup analysis did not show any significant difference compared to Hip-only exercise programs (p > 0.05). Conclusion:Overall, Hip&Knee exercise programs appear to reduce pain and improve function more than other exercise programs and could be used as a primary rehabilitation approach in patients with PFP. However, the difference between the subgroups in most outcome measures suggests that Hip&Knee exercise programs are no more effective than Hip-only exercise programs. &nbsp

Purpose Low back pain (LBP) remains a major worldwide healthcare issue. Recently, spinal exoskeletons were proposed as a potentially useful solution for LBP prevention and vocational reintegration for people who perform heavy load lifting, repetitive movements or work in prolonged static postures. The purpose of this study was to investigate how patients with LBP respond to the novel passive SPEXOR exoskeleton regarding functional performance, discomfort and general user impression. Methods Fourteen patients, with low to moderate LBP (2–7 on a 0–10 scale), performed 12 functional tasks with and without the exoskeleton. In addition to objective performance measures, participants subjectively assessed the level of local low back discomfort, task difficulty and general discomfort on a 0–10 visual analogue scales. Results The SPEXOR exoskeleton had favourable effects on performance and local discomfort during prolonged static forward bending. Minor reductions in performance were observed for sit-stand and ladder climbing tasks. The discomfort associated with the exoskeleton was generally low to moderate (median < 4), except for the 6-min walk test (median = 4.5), which is likely due to the weight of the device and obstruction of upper limb movement. The general impressions were mostly positive, with good adjustability, low interference with the movement and moderate support reported by the participants. Conclusion The SPEXOR exoskeleton is potentially useful for LBP prevention or management, however, further improvements are needed to provide higher levels support during heavy load lifting.

In this study, we investigated the prevalence of inter-limb asymmetries in young volleyball players and assessed the differences in the outcomes of different strength and power tests. The study sample comprised of 54 young volleyball players (25 males). Both limbs were tested for single-leg jumping for distance (forward and lateral single jump and triple jump forward for distance), single-leg vertical counter-movement jump (CMJ), change-of-direction (CoD) ability with 90 and 180° turn tests, unilateral maximal isometric knee extension torque, rate of torque development (RTD), and rate of torque development scaling factor (RTD-SF). For all tests, inter-limb asymmetry indexes were calculated. The average magnitude of the inter-limb asymmetries varied substantially (2.0-31.2 %) among different outcome measures. The agreement in the categorization of participants into ‘’symmetrical’’ or ‘’asymmetrical’’, based on the >10% threshold, was very poor in general, with the exception of the outcomes within the same task (e.g. CMJ power and CMJ force). Similar findings were found for the agreement on the direction of the asymmetries. Inter-limb asymmetry in RTD-SF was weakly associated with the CoD performance (r = 0.30; p = 0.031). Multiple strength and power testing protocols are needed to obtain a comprehensive overview of athlete’s imbalances. The commonly accepted 10 % threshold for classification of individuals as asymmetrical should be reconsidered and reinvestigated. RFD-SF is suggested as a novel outcome measure that can provide additional information to researchers and coaches.

Recently, the two-point method of force–velocity (F–V) profiling of multi-joint human movements has been introduced and validated. In this study, we investigated the validity of estimating the jumping F–V profile using only bodyweight jump and isometric maximal voluntary contraction (MVC) task. Participants (n = 30) performed 3 repetitions of squat (SJ) and counter-movement jumps (CMJ), each at loads that were progressively increased by 10 kg increments, with the number of loads depending on the individual’s ability. Then, 3 isometric MVC trials were performed in 3 knee angles (30°, 60° and 90°). F–V profiling of SJ and CMJ were performed using the multiple-point method, the two-point method, and the novel Jump-MVC method. The results showed poor to fair validity of the novel Jump-MVC method for assessing jumping F–V profile (most ICC 10%, significant systematic bias present, and the presence of proportional bias). The exception was the estimation of theoretical maximal power, which was highly valid for both SJ and CMJ (ICC = 0.91–0.95; CV = 5.0–6.3%). In contrast, validity of the two-point method was excellent (all ICC > 0.90; CV = 2–6%). Although additional studies are needed, present results suggest that the F–V profiling of vertical jumps should be performed using the two-point method with distal loads.

This study aimed to determine if there is a difference in postural stability in highly trained adolescents and young adult athletes regarding sex and sport. The participants were young athletes (n= 464) from seven different sports. We considered the center of pressure (CoP) velocity (total, anterior–posterior (AP) and medial–lateral (ML)), CoP amplitude (AP and ML), and CoP frequency (AP and ML), as assessed by single-leg quiet stance test. Significant interactions were found between sex and sport for all CoP variables (p< 0.02). Additionally, a significant main effect of sport was also found in all CoP variables (p= 0.01). Regarding sex, significant effects were found for all CoP amplitude variables (p= 0.01), as well as for CoP velocity variables, except for CoP ML (p= 0.06). Moreover, there was no sex effect for CoP frequency AP (p= 0.18). The results of the current study confirm the claim that the criteria for optimal postural strategies for elite athletes likely depend on a given sport.

The purpose of this study was twofold: (a) to compare postural control between a group of young female gymnasts (n= 15; age: 11.2 ± 1.9 years) and non-trained peers (n= 15; age: 10.9 ± 2.0 years), and (b) to investigate the effect of an 8-week whole body exercise intervention program on postural control in young female gymnasts. Postural control was assessed by recording center of pressure (CoP) movements during unipedal quiet stance. Velocity and amplitude of CoP movement in anterior-posterior (AP) and medial-lateral (ML) directions were considered. In addition to common trial-averaged CoP outcomes, we also considered the transient behavior of CoP movements, by calculating relative differences between the 1st and 2nd, and the 1st and 3rd 10-s intervals within the whole trial (DIF_21 and DIF_31, respectively). The gymnast group had lower total CoP velocity (Cohen’s d = 0.97) and AP amplitude (Cohen’s d = 0.85), compared to their non-trained peers. The gymnasts also had lower CoP AP amplitude DIF21 (Cohen’s d = 0.73), with almost constant values across all intervals. After the training ML CoP velocity was reduced for 13.12% (Cohen’s d = 0.60), while ML CoP amplitude increased (Cohen’s d = −0.89). &nbsp

The aim of this meta-analysis was to assess the effectiveness of exercise-based interventions for prevention of hamstring injuries in sport. PubMed, Cochrane Central Register of Controlled Trials, Web of Science, ResearchGate, CINAHL, PEDro, ScienceDirect and Google Scholar databases were searched for randomized controlled trials and prospective cohort studies exploring the effects of exercise interventions on hamstring injury incidence. Subgroup analyses were performed to determine effects of several independent variables related to the interventions. Altogether, 17 studies were included. Exercise interventions decreased hamstring injury risk (RR = 0.49; 95%CI = 0.40-0.59

Change of direction (CoD) ability is critical for the success of athletes in many sports. The purpose of this study was to perform a principal component analysis using 9 CoD tests in order to reveal possible subcomponents of CoD ability, which could aid practitioners in test selection. Male and female kinesiology students (n = 76) performed all CoD tests and a 30-m sprint test in a quasi-randomized, counterbalanced order. Three components for males and two components for females were extracted from principle component analysis (variance explained = 82.3 and 71.4%, respectively). It seems that the CoD test should be subdivided into at least two components: a) “pure CoD tests” (such as 505 test, T-test and 180° turn) and maneuverability tests (such as AFL run, Illinois test and Figureof Eight test). Considering that different factors seem to underlie CoD and maneuverability, our findings have important practical implications for training design. If hopping/jumping CoD is important for a given athlete, it should also be tested separately.

Musculoskeletal disorders are the most common work-related health problems. As low back disorders (LBD) are the most problematic, the aim of this study was to provide an in-depth analysis of the nationwide data on sick leaves due to work-related LBDs among workers in Slovenia in 2015–2019 by gender, age and various economic activities (NACE Rev 2 classification). We retrospectively analyzed the Slovene national data for sick leave (SL) rates due to the LBDs between 2015 and 2019. The analyzed SL outcomes were (i) index of temporary disability as a diagnosis-specific loss of calendar days (all calendar days except Sundays) per employee, (ii) frequency of spells as the number of SL cases per 100 employees in one year and (iii) severity as the average duration of one absence from work due to a health condition. A high prevalence of sick leaves due to LBDs in Slovenia was present among young male workers in “mining and quarrying”. In the next age group (20.0–44.9 years), LBD is most frequent in “water supply; sewerage, waste management and remediation activities”. Particular attention should be paid to ‘’agriculture, forestry and fishing’’ which shows a large average sick leave duration and probably a more demanding course of LBDs.

The difference between squat jump (SJ) and countermovement jump (CMJ), termed eccentric utilization ratio (EUR), is frequently suggested as an outcome that can be used in athletic training design. Unlike performance in SJ and CMJ, which is associated with sports performance, the association between EUR and sports performance is almost unexplored. This study aimed to investigate whether EUR is associated with performance in approach jump, linear sprint and change of direction (CoD) tasks in volleyball players. Forty-five male volleyball players performed SJ, CMJ, 25 m linear sprint, approach jump and two CoD tasks (505 test and modified T-test). EUR was calculated based on jump height, peak power, peak force and average power. SJ and CMJ variables showed moderate to high correlation with approach jump performance (r = 0.42–0.70), small correlation with modified T-test (r = 0.33–0.40) and small to moderate correlation with sprint time (r = 0.35–0.49). EUR showed only small associations with performance variables (r = 0.31–0.34). In all linear regression models with performance outcomes as dependent variables, the CMJ height was always the only statistically significant predictor. Our results support the recent arguments that the EUR offers limited insight into the neuromuscular capabilities of athletes.

Achilles tendinopathy (AT) is the most common injury of the Achilles tendon and represents 55–65% of all Achilles tendon clinical diagnoses. AT is characterized by pain, swelling, and impaired performance. ATs can be divided into two types, according to anatomical location—midportion AT (MAT) and insertional AT (IAT). MAT more often occurs in older, less active, and overweight populations, while IAT usually occurs in the more physically active population. Both types of AT can be treated by different treatments, such as surgery, conservative pharmacological treatments, and conservative nonpharmacological treatments. This umbrella review aims to assemble the evidence from all available systematic reviews and/or meta-analyses to determine which conservative nonpharmacological treatments are most commonly used and have the greatest effects. Three major electronic scientific databases (PubMed, Scopus, and Web of Science) were screened. The reference lists of several recent articles on AT were also searched. We found 50 articles that met the inclusion criteria. The methodological quality of the included articles was assessed using the AMSTAR 2 tool. Eccentric (ECC) exercise, isotonic (ISOT) exercise, and acupuncture treatment showed the greatest effects for treating MAT as a standalone therapy. Meanwhile, extracorporeal shockwave therapy and ECC exercise provided the best outcomes for treating IAT as individual treatments. However, an even greater pain decrease, greater function improvement, and greater patient satisfaction for treating either MAT or IAT were achieved with combined protocols of ECC exercise with extracorporeal shockwave therapy (in both cases), ECC exercise with cold air and high-energy laser therapy (in the case of IAT), or ECC exercise with ASTYM therapy (in the case of IAT).

The purpose of this pilot study was to investigate the effects of change-of-direction (CoD) angle (90◦ vs. 180◦ ) and the inclusion of acceleration approach on total task time, CoD deficit, and agreement regarding inter-limb asymmetry direction across CoD tasks. The sample included 13 young male handball players (age: 22.4 ± 3.2 years). The CoD tasks were performed over a 10 m distance with 90◦ and 180◦ turns. Both CoD tasks were performed under two conditions: (1) from the standing start and, (2) with a 10 m prior acceleration approach. Linear sprint times over a 10 m distance were also recorded for the purpose of determining the CoD deficit. The differences between the outcomes of different test variants were assessed with pairwise t-tests and associated Cohen’s d effect size. The agreement in terms of inter-limb asymmetry direction was assessed descriptively, using percentage of agreement. Results showed that the inclusion of the 10 m approach reduced the total task time (mean differences ranging between 0.26 and 0.35 s; d = 2.27–4.02; p < 0.002). The differences between 90◦ and 180◦ turn times were statistically significant under both conditions: (a) without approach (0.44–0.48 s; d = 4.72–4.84; all p < 0.001), and (b) with approach (0.50–0.54 s; d = 4.41–5.03; p < 0.001). The agreement regarding inter-limb asymmetry direction among the tasks was 30.7–61.5%. The differences between the tasks could be explained by the angle–velocity trade-off. The results of this study imply that the CoD tasks should not be used interchangeably when assessing inter-limb asymmetries.

When humans perform isometric ballistic contractions of different intensities, a strong linear relationship is observed between peak force and peak rate of force development. The slope of this relationship, termed the rate of force development scaling factor (RFD-SF), has been proposed as a measure of neuromuscular quickness of submaximal contractions. The RFD-SF is largely dependent on motor unit firing rate and its modulation with contraction intensity, and possibly by agonist–antagonist coordination. The purpose of this review was to critically evaluate the available literature on RFD-SF, including the underlying physiological mechanisms, assessment protocols and methodological considerations, practical application to clinical and sports practice and additional factors such as sex, muscle group, task and fatigue. The main findings of the review are: (a) RFD-SF is very sensitive to impairments associated with aging and neurological diseases, (b) the literature lacks studies on the importance of RFD-SF for athletes, with some evidence that RFD-SF may affect the accuracy of submaximal movements, (c) RFD-SF is not largely influenced by fatigue and sex, (d) the RFD-SF values have been very consistent across muscle groups, with an exception of ankle muscles, (e) the methodology for RFD-SF assessment appears to be well established and standardized. Future research is needed to determine if RFD-SF provides any independent information that cannot be captured with peak force/torque and RFD.

The purpose of this study was to assess the association between bilateral deficit (BLD) in countermovement jump and change of direction (CoD) performance. Therefore, 165 young basketball players (60 females) and 95 young tennis players (39 females) performed two different CoD tasks (90° and 180° turns) and bilateral and unilateral countermovement jumps. BLD was calculated based on jump height, peak power and several phase-specific force impulses (FI). For male athletes, several statistically significant small to moderate associations were found between the CoD performance and BLD (r=0.21–0.52). While the BLD in the propulsive phase FI seems to be most consistently associated with CoD performance, all associations were weak (r=0.21–0.28 in basketball, 0.28–0.36 in tennis). Associations between BLD in total positive (braking and propulsive phase) FI and CoD performance were moderate (r=0.45–0.52) in male tennis players. For female athletes, the associations were even smaller and almost exclusively statistically non-significant. Although indirectly, our results imply that resistance training based on unilateral exercises could be useful to improve CoD performance. It has to be stressed that further training studies are needed to directly confirm this assumption.

We examined the relationships between heights of different vertical jumps and isometric single-joint strength characteristics of ankle, knee, hip, and trunk joints in young male soccer players (n= 117). The highest peak torque and rate of torque development (RTD) outcomes were in low to moderate correlation with jump heights (r= 0.25–0.50). The correlations were generally higher for bilateral than unilateral jumps. Linear regression models accounted for 33–35% and 24.5 of the variance in bilateral and unilateral jump height, respectively. Hip extension peak torque, ankle RTD and trunk lateral flexion peak torque were most consistently included in the regression models. Our results suggest the that single-joint isometric testing does not seem to be useful to detect weaknesses related to vertical jump performance. The relative importance of individual lower limb joints for vertical jumping seems comparable. Trunk strength should not be neglected as the determinant of jumping performance.

IntroductionJumping ability is one of the most important physical qualities in military personnel. Previous training intervention studies have shown equivocal effects on jumping ability. In this study, we assessed the effect of a 12-week resistance exercise programme on countermovement jump (CMJ) performance with and without military equipment.MethodsNinety-six members of the Slovenian Armed Forces (age range 20–47 years) were allocated to the intervention (n=65) and the control (n=32) group. The intervention group performed 2 sessions of full body resistance exercise per week for 12 weeks, while the control group continued with their regular training routine. Before and after the intervention, CMJ assessment using force plates was conducted with and without military equipment.ResultsCMJ testing with and without equipment both exhibited high to excellent relative and absolute reliability. The intervention elicited statistically significant (p=0.011–0.026; η2=0.05–0.06), but small improvements in CMJ height when performed without equipment (from 28.2±3.8 cm to 29.5±3.3 cm) and with equipment (from 25.3±3.7 cm to 27.1±6.1). Other variables showed even smaller or trivial changes.ConclusionsThis study suggests that CMJ with equipment could be a reliable tool to assess jumping performance specific to requirements of military work, which would increase the ecological validity of the testing. The present structured full-body training intervention showed modest improvements in jumping ability in both testing conditions.Trial registration numberNCT0341546.

Traditionally, a larger difference between countermovement (CMJ) and squat jump (SJ) was seen as beneficial, as it reflects the ability to utilize the stretch-shortening cycle. However, strong arguments have been made that this might not always be the case, as larger differences between the jumps could also suggest higher muscle-tendon slack, or poor capability to take this slack up quickly. The purpose of this study was to explore SJ and CMJ, as well as the CMJ to SJ difference (CMJSJDiff) in 9 groups of young athletes. In total, 712 athletes from various disciplines (mean age range: 15.7–36.3 years) and 58 physical education students (mean age: 19.6 years) participated in the study. The major finding of this study was that the groups that showed better SJ and CMJ performance did not show the larger CMJSJDiff. For instance, SJ and CMJ heights were highest in short-distance runners and lowest in long-distance runners, while the largest and smallest CMJSJDiffwas shown in physical education students and speed skaters, respectively. Male athletes had a higher CMJSJDiffthan female athletes, but the difference was very small. While a larger CMJSJDiffhas been traditionally associated viewed as positive, our results could indicate both superior ability to utilize the stretch-shortening cycle, as well as poor ability of rapid force development and excessive muscle slack. Further studies are needed to directly investigate the associations between CMJSJDiffand indicators of athletic performance.

This study compared biomechanical characteristics and physiological responses during rowing on three devices: (i) stable ergometer (STE), (ii) transversally compliant ergometer (TCE) and (iii) frontally compliant ergometer (FCE). Eleven young competitive rowers completed a 2000 meter simulated race under each of the ergometer conditions in a randomized order. Stroke rate, average force, power output, velocity and amplitude of the handle and stretcher or seat, heart rate and blood lactate were measured at 500 m intervals. Force and power at the stretcher were significantly lower (p < 0.03) for TCE, while stroke rate and velocities of the handle and the seat were higher (p < 0.01). No significant differences were observed between STE and FCE in biomechanical parameters. The lowest rowing performance was observed in FCE (p = 0.007), and was accompanied with the highest average heart rate (p = 0.031). Our findings indicate that in TCE, rowers modified their technique, but were able to maintain physiological strain and performance. In contrast, FCE had no effect on rowing biomechanics, but decreased rowing performance and increased physiological strain. It seems plausible that transversal, but not frontal compliance, elicited a biomechanical technique that might reduce the discrepancy between a rowing ergometer and on-water rowing.

Background The role of the measurements of postural stability in the context of screening forankle sprainrisk is still equivocal. Transient characteristics of body sway have been suggested as an alternative or an improvement to traditional whole-trial analyses. Research question Are transient characteristics of body sway sensitive to the history of ankle sprain?. Methods The assessment of 30-s single-leg body sway was performed on a group of 93 athletes from basketball, soccer, tennis and running who reported at least 1 ankle sprain in the last 12 months, while a group of 244 athletes from the same disciplines served as a control group without an ankle sprain reported for the same time period. We considered the mean center-of-pressure (CoP) velocity, CoP amplitude and CoP frequency. In addition to traditional whole-trial variables, we calculated the relative differences between the 1 st and the 2nd (DIF_21) and 1 st and 3rd (DIF_31) 10-s time intervals within the whole trial. Results The indexes of transient characteristics of body sway (i.e., the DIF_21 and DIF_31) were in trivial or weak correlations with whole-trial variables (all r ≤ 0.29). Athletes with ankle sprain history exhibited smaller CoP ML velocity (p = 0.002) and larger CoP ML frequency (p = 0.001). In the injured group, the injured leg exhibited lower total and medial-lateral (ML) CoP velocity (p = 0.005−0.040), as well as lower CoP ML amplitude (p = 0.002) and higher CoP ML frequency (p = 0.010). The transient characteristics of body sway (DIF_21 and DIF_31) were very similar between the groups and between the injured and uninjured legs. Significance Transient characteristics of body sway do not appear to differentiate the athletes with and without a history of ankle sprain. Further research is needed to confirm if the transient characteristics of body sway could be used for detection of risk of falls in older adults or assessment of athletic performance.

Tai Chi has been shown to elicit numerous positive effects on health and well-being. In this study, we examined reactive postural control after sudden unloading horizontal perturbations, which resembled situations encountered during Tai Chi. The study involved 20 participants, 10 in the Tai Chi group (age: 37.4 ± 7.8 years), who had been regularly training the push-hand technique for at least 7 years, and 10 in the control group, consisting of healthy adults (age: 28.8 ± 5.0). Perturbations were applied at three different positions (hips, shoulders, and arms) via the load-release paradigm. Twenty measurements were carried out for each perturbation position. We measured peak vertical and horizontal forces on the ground (expressed percentage of body mass (%BM)), peak center of pressure displacement and peak horizontal and vertical velocities at the knee, hip and shoulder joints. The Tai Chi group exhibited smaller increases in vertical ground reaction forces when perturbations were applied at the hips (11.5 ± 2.1 vs. 19.6 ± 5.5 %BW, p = 0.002) and the arms (14.1 ± 4.2 vs. 23.2 ± 8.4 %BW, p = 0.005). They also responded with higher horizontal force increase after hip perturbation (16.2 ± 3.2 vs. 13.1 ± 2.5 %BW, p &lt, 0.001). Similar findings were found when observing various outcomes related to velocities of vertical movement. The Tai Chi group also showed lower speeds of backward movement of the knee (p = 0.005–0.009) after hip (0.49 ± 0.13 vs. 0.85 ± 0.14 m/s, p = 0.005) and arm perturbations (0.97 ± 0.18 vs. 1.71 ± 0.29 m/s, p = 0.005). Center of pressure displacements were similar between groups. Our study demonstrated that engaging in Tai Chi could be beneficial to reactive postural responses after sudden perturbations in a horizontal direction, however, future interventional studies are needed to directly confirm this. Moreover, because of the age difference between the groups, some confounding effects of age cannot be ruled out.

In this study, we assessed pressure tolerance in 16 healthy participants at the thigh, chest, and pelvic area, using different surfaces (1cm2, 20cm2and different components, used in exoskeleton design), and the effects of different padding materials. Our results showed substantial variability in pressure tolerance among the participants, as well as lower pressure tolerance in females. Regarding the force applied with the exoskeleton components, male participants had higher discomfort threshold (230.3±44.9N compared to females (116.1±24.6N) in the chest area. For the applications with 20cm2surface, the males also showed higher pain threshold at the thigh (89.3±41.8N vs. 34.6±27.2N) and the pelvis (97.6±37.0N vs. 56.1±29.5N). All padding materials increased pressure tolerance for 10–38% (p&nbsp

Change-of-direction (CoD) ability is an important determinant of athletic performance. Muscle strength is among the most important determinants of CoD ability. However, previous studies investigating the relationship between CoD ability and muscle strength focused mostly on flexor and extensor muscle groups, or used multi-joint exercises, such as jumps, squats or mid-thigh pull. The purpose of the present study was to investigate the relationship between CoD ability and strength of ankle, knee, hip and trunk maximal and explosive strength. The participants (n = 327), consisting of male and female basketball players, tennis players and long-distance runners completed isometric strength assessments and CoD testing (90° and 180° turn tests). The times of both CoD tests were associated with muscle strength (peak torques and the rate of torque development variables), with correlation coefficients being mostly weak to moderate (r = 0.2–0.6). Strength variables explained 33%, 62% and 48% of the variance in the 90° turn task, and 42%, 36% and 59% of the variance in the 180° turn task, in basketball players, long-distance runners and tennis players, respectively. Hip and trunk muscle strength variables were the most prevalent in the regression models, especially hip adduction and abduction strength. Our results suggest that the strength of several lower limb muscles, in particular of the hip abductors and adductors, and trunk muscles, but also hip rotators, extensors and flexors, as well as knee and ankle flexors and extensors should be considered when aiming to improve CoD performance.

This research was funded by the Slovenian Research Agency under Grants L5-1845, P5-0147, and BI-RS/18-19-010; Ministry of Education, Science and Technological Development of Republic of Serbia under Grants 451-03-68/2020-14/200015 and 451-03-68/2020-14/200021. The experiments comply with the current laws of the country in which they were performed. The authors have no conflict of interest to declare. The datasets generated during and/or analyzed during the current study are not publicly available, but are available from the corresponding author who was an organizer of the study., This study aimed to assess the within- and between-session reliability of the KiSprint system for determining force-velocity-power (FVP) profiling during sprint running. Thirty (23 males, 7 females; 18.7 +/- 2.6 years;) young high-level sprinters performed maximal effort sprints in two sessions separated by one week. Split times (5, 10, 20 and 30 m), which were recorded with a laser distance meter (a component of the KiSprint system), were used to determine the horizontal FVP profile using the Samozino's field-based method. This method assesses the FVP relationships through estimates of the step-averaged ground reaction forces in sagittal plane during sprint acceleration using only anthropometric and spatiotemporal (split times) data. We also calculated the maximal theoretical power, force and velocity capabilities and the slope of the FV relationship, the maximal ratio of horizontal-to-resultant force (RF), and the decrease in the RF (D-RF). Overall, the results showed moderate or good to excellent within- and between-session reliability for all variables (ICC > 0.75; CV < 10 %), with the exception of FV slope and D-RF that showed low relative reliability (ICC = 0.47-0.48 within session, 0.31-0.33 between-session) and unacceptable between-session absolute reliability values (CV = 10.9-11.1 %). Future studies are needed to optimize the protocol in order to maximize the reliability of the FVP variables, especially when practitioners are interested in the FV slope and D-RF. In summary, our results question the utility of the sprint-based FVP profiling for individualized training prescription, since the reliability of the FV slope and D RF variables is highly questionable., Slovenian Research Agency - Slovenia L5-1845 P5-0147 BI-RS/18-19-010, Ministry of Education, Science and Technological Development of Republic of Serbia 451-03-68/2020-14/200015 451-03-68/2020-14/200021

Spinal exoskeletons have recently emerged as a potential tool to prevent and treat low back pain (LBP) in workers that are involved in heavy load handing and other demanding jobs. However, the widespread use of these devices is still limited. Notably, discomfort and hindrance of movement is often reported by the end-users. Therefore, there is an increasing interest to explore functional and subjective aspect of exoskeleton use. In this paper, we will present a novel battery of tests that was designed to comprehensively assess the effects of spinal exoskeletons on functional performance, discomfort and task difficulty. Next, we provide evidence that specific populations, such as LBP patients, may respond differently to the use of exoskeletons, which should be considered during design and development. Finally, we briefly summarize the findings from a study that investigated the effects of one of the state-of-the-art exoskeletons, by using the previously developed functional test battery.

Spinal exoskeletons have been suggested as an approach for the prevention and rehabilitation of occupational low back pain (LBP). While the state-of-the-art exoskeletons were shown to substantially unload the back, user acceptance is still limited. Perceived discomfort and restriction of freedom of movement are commonly reported. In this pilot study, we explored the differences in subjective responses and user impressions to using passive spinal exoskeleton during a set of simple lifting tasks between LBP patients (n= 12) and asymptomatic individuals (n= 10). Visual analog scales (0–10) were used for all assessments. Overall, the results showed mostly similar responses or slightly more positive responses to the exoskeleton from LBP patients. Most notably, the LBP patients reported a statistically significant (p= 0.048) higher willingness to use the device daily (5.36 ± 4.05) compared to the control group (2.00 ± 1.85) and also gave the device a higher overall grade (6.58 ± 1.98 vs. 4.30 ± 2.26;p= 0.021). This study has demonstrated that individuals with current LBP responded more favorably to the use of the spinal exoskeleton for simple lifting tasks. This implies that current exoskeletons could be appropriate for LBP rehabilitation, but not preventions, as pain-free individuals are less willing to use such devices. Future studies should explore whether different exoskeleton designs could be more appropriate for people with no LBP issues.

Instrumented assessments of quiet-stance postural control typically involve recording and analyzing of body sway signal, most often the center of pressure (CoP) movement. It has been recently suggested that transient characteristics of body sway may offer additional information regarding postural control. In this study, we explored the relationship between whole-trial estimates of body sway (CoP velocity, amplitude, and frequency) and corresponding transient behavior indexes, as well as the effects of leg preference. A total of 705 healthy young athletes performed 30 s single-leg body sway trials for both legs. It was found that the transient characteristics of the body sway (expressed as relative differences between individual time intervals within the trial) are in negligible or weak correlation (r ≤ 0.26) with the corresponding variables, averaged across the whole trial. All CoP variables showed transient characteristics, reflected in statistically significant decrease (CoP velocity and amplitude) or increase (CoP frequency) throughout the trial. The preferred leg showed smaller body sway; however, the effect sizes were very small. Moreover, differences between the legs were also noted in terms of transient characteristics of body sway. In particular, the preferred leg showed earlier reduction in anterior–posterior body sway and larger reduction in medial–lateral body sway. Further studies should focus on examining the clinical utility of indexes of transient behavior of body sway, for instance, their sensitivity to aging-related changes and risk of falling.

Background: The linear relationship between muscle torque and rate of torque rise/relaxation during rapid muscle contractions has been recently introduced as a novel measure of muscle quickness, termed rate of torque development/relaxation scaling factor (RTDSF/RTR-SF). Because the standard assessment protocol includes potentially painful muscle contractions, the first purpose of this study was to validate an adapted RTD-SF/RTR-SF protocol for knee extensor muscles that utilizes lower submaximal intensities and can be used in knee osteoarthritis patients. Methods: A cross-sectional study was performed on a group of healthy controls (n = 24) who underwent the standard RTD-SF/RTR-SF protocol (20–80% of maximum) and the knee osteoarthritis group (n = 24) who underwent the adapted protocol (20–60% of maximum). We calculated the RTD-SF, RTR-SF and the linearity (r 2 ) for both relationships, based on both protocols in controls. Results: The validity of the adapted protocol was acceptable (intraclass correlation coefficient = 0.77–0.93), with low within-participant variation (coefficient of variability

Rate of force/torque development scaling factor (RFD-SF/RTD-SF) has been used as a tool for assessing neuromuscular quickness. The aim was to investigate strength capacities of two major shooting muscle groups and their relationship to basketball shooting performance, and to compare the RFD-SF as well as shooting performance between junior and senior basketball players, and finally to examine the differences in RTD-SF between elbow extensors and volar flexors. In 23 male basketball players (13 juniors and 10 seniors) we assessed maximal isometric torque (TMVC), maximal rate of torque development and RTD-SF slope (kRTD-SF) for elbow extensors and volar flexors. The subjects performed 10 throws at 2.3 m (short) and 8.9 m (long) from the basket. Our results showed similar kRTD-SF and TMVC in both groups. Better shooting performance from short distance was observed in senior players. Significant associations between kRTD-SF, TMVC and shooting performance were found only in juniors. Elbow extensors TMVC was found to have a significant positive large association with shooting performance from long distance. It seems that muscle capacity has an important role in shooting performance in junior compared to players. Sufficient strength capacity of major shooting muscles is important for juniors&rsquo, shooting performance from a long distance.

This study explored transient characteristics of body sway during single-leg quiet stance in young ballet dancers (n=41) and young healthy adults (n=58). We compared the groups in terms of center of pressure (CoP) parameters (CoP velocity and amplitude, averaged across the duration of the 30-s trial), and the transient characteristics of the corresponding parameters, which were expressed as relative differences between the 1st and 2nd, and the 1st and 3rd 10-second interval within the trial (DIF_21 and DIF_31, respectively). Ballet dancers exhibited superior quiet stance postural control (2/5 parameters), as well as different transient behavior (3/5 parameters for DIF_21, and none for DIF_31). Specifically, the ballet dancers reduced body sway more during the 2nd interval, resulting in lower DIF_21 for CoP velocity (total and anterior-posterior) andCoP amplitude(medial–lateral) (effect size=0.42–0.54). The correlations between individual CoP parameters and the corresponding DIF_21 and DIF_31 were very small or trivial (r&nbsp

Falls are a major cause of injury and morbidity in older adults. To reduce the incidence of falls, a systematic assessment of the risk of falling is of paramount importance. The purpose of this systematic review was to provide a comprehensive comparison of the diagnostic balance tests used to predict falls and for distinguishing older adults with and without a history of falls. We conducted a systematic review of the studies in which instrumented (force plate body sway assessment) or other non-instrumented balance tests were used. We analyzed the data from 19 prospective and 48 retrospective/case-control studies. Among the non-instrumented tests, the single-leg stance test appears to be the most promising for discrimination between fallers and non-fallers. In terms of body sway measures, the center-of-pressure area was most consistently associated with falls. No evidence was found for increased benefit of the body sway test when cognitive tasks were added, or the vision was eliminated. While our analyses are limited due to the unbalanced representation of different test and outcome measures across studies, we can recommend the single-leg test for the assessment of the risk of falling, and the measurements of body sway for a more comprehensive assessment.

Recently, several spinal exoskeletons were developed with the aim to assist occupational tasks such as load-handling and work in prolonged static postures. While the biomechanical effects of such devices has been well investigated, only limited feedback to the developers is usually provided regarding the subjective perceptions of the end-users. The aim of this study was to present a novel battery of tests, designed to assess functional performance and subjective outcomes during the use of assistive trunk exoskeletons, and to assess its test-retest reliability. The battery of tests consists of 12 different simple functional tasks. Twenty participants were included in an intra-session reliability test and repeated the tests within 7–10 days to assess inter-session reliability. They were wearing a novel passive spinal exoskeleton during all trials. The outcomes included quantitative and subjective measures, such as performance time and rating of discomfort and perceived task difficulty. The majority of the outcome measures were reliable within session and between sessions (ICC or α > 0.80). Systematic effects were observed in a few tasks, suggesting that familiarization trials will be needed to minimize the learning effects. The novel battery of tests could become an important easy-to-use tool for functional testing of the spinal exoskeletons in addition to more specific biomechanical and physiological testing. Further studies should address the reliability of the present battery of tests for assessing specific populations, such as low back pain patients and explore how to minimize systematic effects that were observed in this study.

BACKGROUND: Sedentary behavior has been recognized as an important risk factor in the development of several chronic diseases. Active workstations have been proposed as an effective countermeasure. While such interventions likely reduce sedentary time, concerns regarding the effects on work performance and cognitive function remain. OBJECTIVE: To use meta-analyis to critically evaluate the work performance and cognitive function effects of cycle and treadmill desks as workplace interventions against sedentary behavior. METHODS: In February 2018, a data search was conducted. Parallel and crossover design studies evaluating workplace interventions compared to conventional seated conditions were included. RESULTS: Eighteen studies met the inclusion criteria. Both interventions reduced typing speed (cycling: SMD = -0.35, p = 0.04; treadmill: SMD = -0.8, p CONCLUSION: Cycle and treadmill desks affect work performance, but most likely not due to a decrease in cognitive function. Further research is needed to determine whether the degree of work performance decline is acceptable, considering the many positive effects of implementing active workstations in the office environment.

Resistance exercise is widely recommended strategy to improve functional ability and quality of life of the elderly. Novel resistance exercises approaches, such as flywheel exercise have recently emerged as superior alternatives to traditional methods. Eccentic exercise methods are well documented to elicit different and often the more pronounced effect on physical ability and function of the elderly. By reviewing the relevant scientific literature, we found that only limited studies have investigated the effects of flywheel exercise in the elderly, however, the results are very promising. Thus, more research is desired to explore the effect of flywheel exercise type in elderly individuals.

Background Recently, the rate of torque development scaling factor (RTD-SF) has been proposed as a useful tool that could contribute to a more comprehensive insight into muscular capacity. While lower RTD-SF is associated with ageing and certain neuromuscular diseases, it remains unknown whether this novel measure is associated with the postural control in the older adults. Research question Are hip abductor muscle strength, RTD and RTD-SF associated with responses to external postural perturbations in medio-lateral direction in older adults? Methods Twenty healthy older adults (14 females, 6 males) were assessed for hip abductor muscle strength, RTD and RTD-SF, using a custom-built dynamometer. Perturbations were applied at waist level (4 perturbation intensities, 15 repetitions each) using a wire-pull paradigm, with centre-of-pressure (CoP) being recorded with force plates. For each condition (i.e. perturbation intensity), medio-lateral displacement and velocity of the CoP were computed. For both parameters, within-individual variation (representing consistency of the responses), expressed by the standard deviation (SD) of CoP parameters was also considered. Pearson correlation coefficients were computed between parameters of hip muscle capacity and CoP responses and SD values of CoP responses. Results RTD-SF was moderately positively related to the consistency of the responses of both CoP displacement and velocity (r = 0.53−0.56; p = 0.011−0.016) at the lowest level of the perturbation magnitude (15 N). No other statistically significant relationships were found (all r Significance RTD-SF could play a role in preserving postural balance in older adults when low-intensity perturbations are applied. RTD-SF is a novel outcome measure that could represent an important alternative clinical tool to traditional strength assessments. It could represent a supplementary tool to assess the risk of falls, however, several limitations and ambiguities need to be resolved by future research before it can be utilized in practice.

We explored the associations between force-velocity-power (FVP) profiles and inter-limb asymmetries in FVP profiles obtained during unilateral jumping and single-leg isokinetic knee extension and flexion tasks. Thirty (13 senior and 17 junior) basketball players performed unilateral jumps with different levels of unloading (0-40% body mass) and isokinetic knee extension and flexion at different angular velocities (60-300 degrees/s) with each leg. Senior and junior basketball players exhibited similar jump performance, normalized knee extensor and flexor strength, and relatively similar jumping and isokinetic FVP profiles. No significant associations between unilateral jump and isokinetic knee extension and flexion FVP parameters were found (all r 0.05). Inter-limb asymmetries had no or very weak associations with unilateral jump height (-0.2 0.1) ; also, inter-limb asymmetries in jump and isokinetic FVP parameters were generally weakly associated (median r < 0.1). Finally, unilateral jump height was weakly-to-moderately associated with isokinetic F-0, jumping P-max, and normalized knee extension isokinetic peak torque at 60 degrees/s and 240 degrees/s (r = 0.35-0.57). These results suggest that the generalizability of the FVP profile of isolated muscle groups to complex ballistic tasks is weak.

Runners are particularly prone to developing overuse injuries. The most common running-related injuries include medial tibial stress syndrome, Achilles tendinopathy, plantar fasciitis, patellar tendinopathy, iliotibial band syndrome, tibial stress fractures, and patellofemoral pain syndrome. Two of the most significant risk factors appear to be injury history and weekly distance. Several trials have successfully identified biomechanical risk factors for specific injuries, with increased ground reaction forces, excessive foot pronation, hip internal rotation and hip adduction during stance phase being mentioned most often. However, evidence on interventions for lowering injury risk is limited, especially regarding exercise-based interventions. Biofeedback training for lowering ground reaction forces is one of the few methods proven to be effective. It seems that the best way to approach running injury prevention is through individualized treatment. Each athlete should be assessed separately and scanned for risk factors, which should be then addressed with specific exercises. This review provides an overview of most common running-related injuries, with a particular focus on risk factors, and emphasizes the problems encountered in preventing running-related injuries.

Runners are at relatively high risk for sustaining an overuse injury. While many risk factors have been documented so far, previous reviews have mostly failed to identify effective interventions to lower injury risk in runners. To review the high-quality evidence on two types of preventive interventions – movement therapy interventions and training-modification interventions, regarding running-related injury prevention. Pubmed (MEDLINE), PEDro and Cochrane Central Register of Controlled Trials databases were searched in April 2017, with no date or language restrictions, using following search terms: running injury prevention, running injury therapy, running injury incidence, running injury exercise and running injury risk. Studies were included if they were a randomized controlled trial or prospective cohort study, investigated the effects of movement therapy or training modification interventions, contained a population of runners or other populations, involved in running (e.g. military recruits), and reported lower extremity injury incidence rates specific to running. In total, 4935 citations were identified, 69 of which were retrieved for full-text evaluation. Seven articles met the inclusion criteria and were included in meta-analysis. Two separate meta-analyses were carried out for both intervention types. First meta-analysis showed no preventive effects of movement therapy interventions, with an overall risk ratio of 0.98 (p = 0.81, I2 = 42 %). The second meta-analysis showed no overall preventive effect of training modifications, with an overall risk ratio of 0.78 (p = 0.35, I2 = 79%). No evidence was found to support the preventive effects of movement therapy or training modification. This may primarily be due to non-optimal intervention designs, such as using inappropriate placebo exercises. Preventive programs may also be more effective when carried out prior to running program onset.

Purpose. The aim of this article was to evaluate the effects of cycle and treadmill desks on energy expenditure and car- diovascular and biochemical indicators in sedentary workers.Materials and methods. In February 2018, six databases were searched. Both parallel and crossover design studies evaluating workplace cycle and treadmill desks compared to a conventional seated condition were included.Results. Twenty-two studies met the inclusion criteria. Cycle and tread- mill desks significantly increased energy expenditure (standard mean difference [SMD]=3.84,p&nbsp

An abundance of literature has investigated the association between low back pain (LBP) and physical ability or function. It has been shown that LBP patients display reduced range of motion, decreased balance ability, impaired proprioception, and lower strength compared to asymptomatic persons. The aim of this study was to investigate the differences between LBP patients and healthy controls in terms of several physical abilities. Based on the premised that different biomechanical and physiological causes and consequences could be related to different types of LBP, a secondary exploratory attempt of the study was to examine the differences between LBP subgroups based on the pain location (local or referred) or type of pathology (discogenic or degenerative) on the level of impairment of function and ability. Participants performed range of motion tests, trunk maximal voluntary contraction force tests, a sitting balance assessment, the timed up-and-go test, the chair rise test, and the trunk reposition error test. Compared to the control group, symptomatic patients on average showed 45.7% lower trunk extension (p &lt, 0.001, η2 = 0.33) and 27.7 % lower trunk flexion force (p &lt, 0.001, η2 = 0.37) during maximal voluntary contraction. LBP patients exhibited decreased sitting balance ability and lower scores in mobility tests (all p &lt, 0.001). There were no differences between groups in Schober’s test and trunk repositioning error (p &gt, 0.05). No differences were observed among the LBP subgroups. The exploratory analyses are limited by the sample size and uncertain validity of the diagnostic procedures within this study. Further studies with appropriate diagnostic procedures and perhaps a different subgrouping of the LBP patients are needed to elucidate if different types of LBP are related to altered biomechanics, physiology, and function.