Context: Asymmetrical movements of trunk and lower-extremity are common during the bridge exercise on the unstable condition. However, no studies have investigated whether visual biofeedback of pressing pressure on the unstable surface changes muscle activation patterns of trunk and hip extensors and pelvic rotation during the bridge exercise. Objective: To investigate how visual biofeedback of pressing pressure influences symmetrical activity of lumbar and hip extensor and pelvic rotation. Design: Cross-sectional study. Setting: Laboratory. Participants: Twenty healthy males participated in this study. Interventions: The participants performed 2 versions of the bridge exercise: the standard bridge exercise and the bridge exercise with visual biofeedback using amount of pressing pressure on the sling. Main Outcome Measures: Surface electromyography was used to measure the symmetry (ie, the difference between dominant and nondominant sides) of muscle activation in the bilateral erector spinae, gluteus maximus, and hamstring muscles, and motion sensors were used to assess pelvic rotation. Symmetry of pressing pressure was measured using a tension meter. Results: The differences between the dominant and nondominant pressing pressures and differences between the electromyography activity of the dominant and nondominant erector spinae, gluteus maximus, and hamstring were significantly smaller during the bridge exercise with visual biofeedback than during the standard bridge exercise (P < .05). In addition, there was significantly less pelvic rotation during the bridge exercise with visual biofeedback than during the standard bridge exercise (P < .05). Conclusions: The present findings suggest that visual biofeedback strategy may be a useful method for enhancing the symmetrical activation of the erector spinae, gluteus maximus, and hamstring and for reducing pelvic rotation during the bridge exercise on the unstable surface.
Soo-Yong Kim, Jae-Seop Oh, and Min-Hyeok Kang
Gabriel dos Santos Oliveira, João Breno de Araujo Ribeiro-Alvares, Felipe Xavier de Lima-e-Silva, Rodrigo Rodrigues, Marco Aurélio Vaz, and Bruno Manfredini Baroni
Context: Eccentric knee flexor strength assessments have a key role in both prevention and rehabilitation of hamstring strain injuries. Objective: To verify the reliability of a clinical test for measuring eccentric knee flexor strength during the Nordic hamstring exercise using a commercially available handheld dynamometer. Design: Reliability study. Setting: Physical Therapy Laboratory, Federal University of Health Sciences of Porto Alegre (Brazil). Participants: Fifty male amateur athletes (soccer or rugby players; 24  y). Main Outcome Measures: Eccentric knee flexor strength. Results: When compared with a load cell–based device, the clinical test using a handheld dynamometer provided smaller force values (P < .05) with large effect sizes (.92–1.21), moderate intraclass correlation (.60–.62), typical error of 30 to 31 N, and coefficient of variation of 10% to 11%. Regarding the test–retest reproducibility (2 sessions separated by 1 week), the clinical test provided similar force values (P > .05) with only small effect sizes (.20–.27), moderate to good correlation (.67–.76), typical error of 23 to 24 N, and coefficient of variation of 9% to 10%. Conclusion: The clinical test with handheld dynamometer proposed by this study can be considered an affordable and relatively reliable tool for eccentric knee flexor strength assessment in the clinical setting, but results should not be directly compared with those provided by load cell–based devices.
Aaron Byrne, Clare Lodge, and Jennifer Wallace
Context: Single-leg stability has been associated with injury risk and is a key component of many injury prevention interventions. Methods of measuring single-leg stability are varied yet often unreliable. Objective: To establish within- and between-day test–retest reliability for single-leg time to stabilization (SL-TTS) following a drop-landing maneuver of 20 cm in height among a healthy cohort. Design: Test–retest reliability study. Setting: Healthy cohort from a third-level educational institution. Participants: Nineteen (11 females and 8 males) healthy individuals. Main Outcome Measures: The SL-TTS in the vertical plane. Results: The SL-TTS showed good within-day (intraclass correlation coefficient = .715) and excellent between-day (intraclass correlation coefficient = .83) test–retest reliability. The minimal detectable change was calculated as 171.6 ms for within-day contexts and 123.8 ms for between-day contexts. Conclusions: This method of measuring SL-TTS is reliable and could be used to detect changes over time in a healthy cohort. This could be of value to clinicians in injury risk factor identification or assessing the effectiveness of single-leg stability training. However, further research is needed to investigate its reliability in pathological populations.
Chloe McKay, Johanna M Hoch, and Deirdre Dlugonski
Clinical Scenario: Physical inactivity among adults is prevalent. Physical literacy is a potential modifiable factor that, if targeted effectively, may increase physical activity and decrease the risk of health conditions that are associated with physical inactivity. Clinical Question: Are there effective intervention strategies available to improve physical literacy in adults? Summary of Key Findings: Two nonrandomized experimental studies were included. Both studies assessed changes in physical literacy before and after a physical literacy intervention using two different sets of physical literacy outcome measures. Clinical Bottom Line: There is currently Level 2, limited quality, patient-oriented evidence that indicates that physical literacy can be improved in an adult population. The creation of a valid and reliable physical literacy outcome measure for adults is a necessary next step to enhance knowledge about physical literacy among adults. Future research should use a randomized control trial design to test the efficacy of physical literacy interventions with valid and reliable outcome measures. Strength of Recommendation: There is Level 2, limited quality, patient-oriented evidence for physical literacy interventions among adults. Due to the limited number of, and lack of consistency between studies, the authors did not make a formal grade recommendation.
Iva Obrusnikova, Albert R. Cavalier, Richard R. Suminski, Ashleigh E. Blair, Cora J. Firkin, and Ashley M. Steinbrecher
Adults with an intellectual disability have significantly lower levels of fitness compared with the general population. This study examined the effects of a 13-week theoretically guided, community-based, multicomponent resistance training intervention, resistance training for empowerment, on muscular strength and independent functional performance in 24 adults with an intellectual disability, aged 18–44 years. Twelve participants were randomly allocated to an experimental group and 12 to an active control group. An analysis of covariance revealed that the experimental group had significantly greater increases (p < .05) on the chest press and leg press one-repetition maximum tests and the 6-min walk test from the baseline to postintervention compared with the control group. The experimental group correctly and independently performed a significantly greater number of steps of resistance training exercise tasks than the control group. Marginal significance and large effect sizes were found for the prone plank test and the stair climb test. The resistance training for empowerment was effective in promoting muscular strength and independent functional performance among adults with an intellectual disability.
Jennifer L. Ostrowski, Alexa Beaumont, and Emily Dochterman
Clinical Scenario: Pathologies of the long head of the biceps brachii (LHB) tendon are a source of shoulder pain in many people. It is important to have a reliable assessment of the LHB tendon to make an accurate diagnosis and provide the correct treatment or referral if necessary. Shoulder ultrasound is very accurate in the diagnosis of rotator cuff tears. However, its ability to detect pathologies of the LHB tendon is still unclear. Clinical Question: In patients with shoulder pain, can musculoskeletal ultrasound accurately diagnose LHB tendon pathologies? Summary of Key Findings: Four high-quality cohort studies met inclusion criteria and were included in the critical appraisal. The STrengthening the Reporting of OBservational studies in Epidemiology checklist was used to score the articles on methodology and consistency. Three studies evaluated accuracy in diagnosis of full-thickness tears and found high sensitivity (SN) and specificity (SP). Three studies evaluated accuracy in diagnosis of partial-thickness tears and found low SN and negative predictive value, but high SP and positive predictive value. Two studies evaluated tendon subluxation/dislocation and found high SN and SP. Two studies evaluated tendinitis and found moderate SN and high SP. Clinical Bottom Line: There is moderate to strong evidence to support the use of musculoskeletal ultrasound in diagnosis of LHB tendon pathology. Strength of Recommendation: There is grade B evidence that musculoskeletal ultrasound can accurately diagnose full-thickness tears and tendon subluxation/dislocation; can rule in partial-thickness tears (based on SP and positive predictive value), but not rule out partial-thickness tears; and can rule in tendinitis (based on SP and positive predictive value), but not rule out tendinitis.
Kentaro Kodama, Hideo Yamagiwa, and Kazuhiro Yasuda
As previous studies have suggested that bimanual coordination is important for slacklining, the authors questioned whether this important skill plays a role in the performance of a fundamental task of slacklining. To address this question, the authors compared single-leg standing on the slackline between novices and experts in terms of bimanual coordination dynamics within a dynamical systems framework using relative phase and recurrence quantification analysis measures. Five novices and five experts participated in the experiment. Participants were required to perform single-leg standing on a slackline. To collect motion data while slacklining, the authors used a 3D motion capture system and obtained time series data on the wrist position of both hands. The authors compared bimanual coordination dynamics between novices and experts. Although this preliminary study was limited in its sample size, the results suggest that experts tend to show a more antiphase coordination pattern than novices do and that they can more sustainably coordinate their hands compared with novices in terms of temporal structure in diagonal-related recurrence measures (i.e., maxline, mean line, and percentage determinism).
Geneviève N. Olivier, Christopher S. Walter, Serene S. Paul, Leland E. Dibble, and Sydney Y. Schaefer
Motor performance is classically described as improving nonlinearly with practice, demonstrating rapid improvements early in practice with stabilization later, which is commonly modeled by exponential decay functions. However, retrospective analyses of our previously collected data challenge this theoretical model of motor skill acquisition, suggesting that a majority of individual learners actually demonstrate patterns of motor improvement different from this classical model. A convenience sample of young adults, older adults, and people with Parkinson disease trained on the same functional upper-extremity task. When fitting three-parameter exponential decay functions to individual participant data, the authors found that only 13.3% of young adults, 40.9% of older adults, and 66.7% of adults with Parkinson disease demonstrated this “classical” skill acquisition pattern. Thus, the three-parameter exponential decay pattern may not well-represent individuals’ skill acquisition of complex motor tasks; instead, more individualized analysis methods may be warranted for advancing a theoretical understanding of motor skill acquisition.
Samar Ezzina, Clément Roume, Simon Pla, Hubert Blain, and Didier Delignières
The analysis of stride series revealed a loss of complexity in older people, which correlated with the falling propensity. A recent experiment evidenced an increase of walking complexity in older participants when they walked in close synchrony with a younger companion. Moreover, a prolonged experience of such synchronized walking yielded a persistent restoration of complexity. This result, however, was obtained with a unique healthy partner, and it could be related to a particular partner’s behavior. The authors’ aim was to replicate this important finding using a different healthy partner and to compare the results to those previously obtained. The authors successfully replicated the previous results: synchronization yielded an attraction of participants’ complexity toward that of their partner and a restoration of complexity that persisted in two posttests, 2 and 6 weeks after the end of the training sessions. This study shows that this complexity restoration protocol can be applied successfully with another partner, and allows us to conclude that it can be generalized.
J.D. DeFreese, Samuel R. Walton, Avinash Chandran, and Zachary Y. Kerr
The COVID-19 pandemic has resulted in changes to the structure of sport and the experiences of athletes. In this commentary, we consider how these changes, including schedule disruptions and the early termination of careers, have contributed to a reconsideration of how athlete transition should be defined, examined, and intervened upon. We outline our rationale for this proposed reconfiguration, including implications for researchers and practitioners working with athletes during the COVID-19 pandemic and beyond. For researchers, we recommend updating the transition definition, reconsidering the measurement of salient transition-related variables, and utilizing study designs/methods that best facilitate this work. For practitioners, we recommend considering the dynamic nature of transition within holistic athlete care, building momentum on mental health destigmatization achieved during the pandemic, athlete transition education, and clinician advocacy for transition-related resources for athletes. Ultimately, we hope this work will spark continued innovations in athlete transition research and practice moving forward.