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Smartphones, with embedded accelerometers, may be a viable method to monitor gait variability in the free-living environment. However, measurements estimated using smartphones must first be compared to known quantities to ensure validity. This study assessed the validity and reliability of smartphone-derived gait measures compared to a gold-standard footswitch system during overground walking. Seventeen adults completed three 8-minute overground walking trials during 3 separate visits. The stride time series was calculated as the time difference between consecutive right heel contact events within the footswitch and smartphone-accelerometry signals. Linear (average stride time, stride time standard deviation, and stride time coefficient of variation) and nonlinear (fractal scaling index, approximate entropy, and sample entropy) measures were calculated for each stride time series. Bland–Altman plots with 95% limits of agreement assessed agreement between systems. Intraclass correlation coefficients assessed reliability across visits. Bland–Altman plots revealed acceptable limits of agreement for all measures. Intraclass correlation coefficients revealed good-to-excellent reliability for both systems, except for fractal scaling index, which was moderate. The smartphone system is a valid method and performs similarly to gold-standard research equipment. These findings suggest the development and implementation of an inexpensive, easy-to-use, and ubiquitous telehealth instrument that may replace traditional laboratory equipment for use in the free-living environment.

Concussion history, trunk motion, and lower extremity biomechanics associate with musculoskeletal injury risk. We aimed to examine the interaction between concussion history and trunk motion as possible modifiable factors for injury risk biomechanics during jump landing and cutting. Division I female athletes (24 with, 20 without concussion history) performed jump landings and jump-to-cuts at 45° in the opposite direction of the landing limb. We used multiple linear regressions with interaction terms to examine ankle dorsiflexion angle, knee flexion and abduction angle, and external knee flexion and abduction moment. We observed a group by trunk flexion interaction for nondominant external knee flexion moment (P = .042) during jump landing. Concussion history associated with increased external knee flexion moment as trunk flexion increased. We observed a group by trunk flexion interaction for the dominant limb dorsiflexion angle (P = .044), and group by trunk lateral bending interactions for the dominant (P = .039) and nondominant limb (P = .016) external knee flexion moment during cutting. During cutting, concussion history associated with decreased dominant dorsiflexion angles as trunk flexion increased, and decreased dominant and nondominant external knee flexion moment as lateral bending toward the planted limb increased. Concussion history associated with atypical biomechanics as trunk flexion and lateral bending increased.

This study examined doctoral students’ occupational socialization experiences in U.S. adapted physical activity doctoral programs. Twenty-eight doctoral students were recruited and participated in semistructured, in-depth interviews. Interview transcripts were analyzed through a collaborative qualitative analysis, which resulted in the construction of four themes: (a) early socialization experiences foster a positive, but limited impression of physical education and physical activity; (b) doctoral education is pursued to have a greater impact on the disability community; (c) relationships with socializing agents provide support during doctoral education; and (d) coursework and learning in the community facilitate preparation for faculty roles. The findings indicate that there are several similarities between doctoral students and their peers in other doctoral degree programs. Some of these similarities point to issues that may concern prospective doctoral students and faculty members in adapted physical activity terminal degree programs.

Attentional focus strategies, especially external focus, are associated with improvements in mechanisms of postural control. This can be important in reducing sports injuries in practices such as running, which has seen an increase in adherence. However, the impacts of these strategies on postural control in runners are unclear. This study aimed to investigate the effects of internal and external focus strategies on postural control performance with different bases of support tasks in runners. A total of 19 young adults (18–38 years old) were divided into a running group (n = 9) and a control group (n = 10). Posturography tests were performed on stable and unstable surfaces, under control, and internal and external focus conditions. The distance, mean velocity, and total velocity of the center of pressure were analyzed (p ≤ .05). There was a reduction in oscillation under external focus compared to internal and control conditions, as well as under internal focus compared to the control condition. A Group × Surface × Focus interaction for the variables distance and mean velocity in the mediolateral direction was found only for the control group. However, no significant effects were found between groups for postural control performance. Attentional focus strategies were able to reduce postural sway, with external focus condition being the most effective. Practitioners can benefit from these strategies to increase postural control performance to help reduce the number of injuries and improve sports performance. It is speculated that the effects of attentional control strategies on postural control may differ depending on the specific adaptations of each sport.

Aim: To assess the adaptive response of older adults with a history of falls in a single Perturbation-Based Balance Training (PBT) session by examining the margin of stability (MoS) and the number of falls. Methods: Thirty-two older adults with a history of falls underwent a treadmill walking session lasting 20–25 min. During the PBT protocol, participants experienced 24 unexpected perturbations delivered in two ways: acceleration or deceleration of the treadmill belt, with 12 perturbations in each direction. The MoS in the anteroposterior direction was assessed for the first and last perturbations of the session, during the perturbation step (N) and the recovery step (REC), along with the number of falls during the training session. Results: There was no statistically significant difference in MoS between the first and last perturbations (acceleration and deceleration) for steps N and REC. Regarding the number of falls, a significant reduction was found when comparing the first half with the second half of the training session (p = .033). There were 13 falls in the first half and only three in the second half of the PBT session. Conclusion: Older adults with a history of falls exhibited an adaptive response with a reduction in the number of falls during a single session of PBT despite not showing changes in the MoS.

Movement disorders, such as stroke and amyotrophic lateral sclerosis, result in loss of upper limb function and, hence, severe impairments of bimanual coordination. Although motor imagery is increasingly used to enhance neurorehabilitation, cognitive and neurophysiological parameters that inform effective strategies remain elusive. The aim of the present study is to elucidate the neural dynamics that underlie learning during real and imagined movement using both unimanual and bimanual coordination patterns. The post movement beta rebound (PMBR) has been implicated as a biomarker of motor control and therefore was the focus of this study. Healthy adults (n = 21) learned a visuomotor tracking task in a single session using either one or both hands while brainwaves were captured using electroencephalography. Postmovement beta rebound was evident in the sensorimotor cortex for both unimanual and bimanual conditions. Task-related power of the beta band demonstrated that actual unimanual movement requires greater contralateral activity compared with both actual bimanual movement and imagined movement of either condition. Notably, the PMBR was evident even in imagined movement, although to a lesser extent than real movement. Neurophysiological results support a functional role for beta band in movement. Results of these data may inform neurorehabilitation strategies for patients recovering from movement disorders of the upper limbs.

Hip flexibility is an important biomechanical factor for a baseball pitcher. However, there have been limited investigations into the association between upper-extremity joint stresses and ball velocity and hip flexibility, as assessed via motion patterns during the pitch. The purpose of this study was to provide a detailed kinematic description of the lead hip during the pitch and determine the association between lead hip motion and both ball velocity and the elbow varus moment. This study was a secondary analysis of the kinematic and kinetic data previously collected on 99 collegiate-level baseball pitchers using standard optoelectronic motion capture. Significant associations were noted between lead hip internal rotation and both peak ball velocity and the elbow varus moment. The data indicated that for every 10° increase in internal lead hip rotation, ball velocity increased by 0.6 m/s (P < .001, r ² = .26), and the elbow varus moment increased by 5 N·m (P < .001, r ² = .33). The results of this study suggested that internal hip rotation may be an important means of identifying pitchers that may be at risk for future injury.

The peak compressive forces at L5/S1 during patient transfers have been estimated. However, no study has considered the actual patient body weight that caregivers had to handle during transfers. We developed a simple kinematic model of lifting to address this limitation. Fifteen prospective health care providers transferred a 70-kg individual who mimicked a patient (“patient”) from bed to wheelchair. Trials were acquired with the patient donning (weighted) and doffing (unweighted) a 5-kg weight belt. Trials were also acquired with and without knee assistance and a mechanical lift. During trials, kinematics and kinetics of transfers were recorded to estimate the peak compressive force at L5/S1 using static equilibrium equations. The peak compressive force was associated with the transfer method (P < .0005), and the compressive force was 68% lower in lift-assisted than manual transfer (2230 [SD = 433] N vs 6875 [SD = 2307] N). However, the peak compressive force was not associated with knee assistance, nor with a change in the patient body weight. Our results inform that mechanical loading exceeding the National Institute for Occupational Safety and Health safety criterion occurs during patient transfers, confirming a high risk of lower back injuries in caregivers. However, the risk can be mitigated with the use of a mechanical lift.