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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.

Context: Instrument-assisted soft tissue mobilization (IASTM) continues to increase in popularity and utilization among manual therapists. Despite its popularity, little is known about the consistency in peak or average forces that clinicians apply when performing IASTM treatments with a 2-handed grip. The purpose of this study was to examine intraclinician consistency in peak and average forces when applying a 2-handed IASTM grip. Design: Randomized crossover study conducted in a university biomechanics laboratory. Methods: Five (5) licensed athletic trainers with prior IASTM training used 5 different IASTM instruments to apply simulated treatment. Average peak forces (F_peak) and average mean forces (F_mean) were collected via force plate for all 5 IASTM instruments with a skin simulant attached. Descriptive statistics, coefficients of variation (CVs), box and density plots, and Bland–Altman plots were assessed. Results: The clinicians’ average F_peak ranged from 3.0 N to 11.6 N and average F_mean from 1.9 N to 8.1 N. F_peak CVs for all instruments ranged from 14% to 31%, and F_mean CVs ranged from 15% to 35%. Bland–Altman plots indicated that for both F_peak and F_mean, 97% of the data points fell within the limits of agreement across instruments and clinicians. Mean differences across instruments ranged from 0.9 N (91.8 g) to 4.1 N (418.1 g) for F_peak and from 1.0 N (102.0 g) to 2.8 N (285.5 g) for F_mean. Thus, CVs, box and density plots, and Bland–Altman plots supported general force application consistency. Conclusion: Trained IASTM clinicians produced consistent treatment application forces (ie, F_peak and F_mean) within treatment sessions during 2-handed simulated application.

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.

Context: As blood flow restriction gains popularity across different populations (eg, young and older adults) and settings (eg, clinical and sports rehabilitation), the accuracy of blood flow restricted percentage becomes crucial. We aimed to compare manually measured arterial occlusion pressure (AOP) among young adults to understand whether lower limb composition affects the pressure required to achieve AOP. The results will shed light on the adequacy of published calculations used to estimate AOP in practical and research settings. Design: An observational cross-sectional study design was implemented to examine the relationship between lower limb composition, lower limb circumference, and measured AOP. Methods: Twenty-two participants (12 males, 26 [4] y, 1.74 [0.07] m, 73.2 [12.5] kg) underwent a whole-body Dual-energy X-ray Absorptiometry scan before AOP (in millimeters of mercury) and lower limb circumference (in centimeters) were determined. In a supine position, a 10-cm wide cuff was manually inflated on the dominant leg to the point where a pulse could no longer be detected by a Doppler ultrasound of the posterior tibial artery to determine AOP. Lower limb composition (fat, muscle, and bone mass [in grams]) was obtained from the Dual-energy X-ray Absorptiometry scan. Results: Lower limb muscle mass had a moderate negative relationship with AOP (r ² = .433, β = −0.004) and a moderate positive relationship with lower limb circumference (r ² = .497, β = 0.001). Lower limb circumference had the weakest relationship with AOP (r ² = .316, β = 0.050) of all measures. Conclusions: The reported relationships between lower limb muscle mass, lower limb circumference, and AOP suggest that as muscle mass increases, lower limb circumference also increases, yet AOP decreases. This implies that limb circumference should not be used as the primary measure for calculating AOP within the sampled population. We recommend individually measuring AOP when implementing blood flow restriction in all exercise modalities.

Context: Racial identity may associate with clinical outcomes following sport-related concussion (SRC). This study compared clinical outcome scores before and after recovery from a SRC between Black or White college athletes. Design: Prospective cohort. Methods: Participants were self-reported White (n = 61, 18.5 [1.1] y of age) and Black (n = 24, 18.3 [1.1] y of age) NCAA Division 1 college athletes. The revised Head Injury Scale (HIS-r), the Immediate Postconcussion and Cognitive Test (ImPACT) battery, and the Sensory Organization Test (SOT) at baseline (T1), upon symptom resolution (T2) following a diagnosed SRC, and upon establishing a new baseline assessment (T3). Race was collected from paper and electronic medical records. The revised Head Injury Scale total symptom severity, ImPACT’s Verbal Memory, Visual Memory, Visual Motor Speed (VMS), and Reaction Time, and the SOT Equilibrium Score, were compared between groups at each time point. Multivariate analyses of variance (2 [group] × 3 [time]) were used to compare revised Head Injury Scale, ImPACT, and SOT outcome scores. Post hoc analyses consisted of independent and paired sample t tests. Results: A significant main effect for time (λ = 0.66, F _2,82 = 21.55, P < .001, ${\eta }_{\mathrm{p}}^2=.34$ ) was observed for the SOT. White athletes significantly improved on the Equilibrium Score between all time points (all P < .006). Similarly, Black athletes significantly improved on the Equilibrium Score between T1–T2 and T1–T3 (all P < .001). A significant main effect of time was observed for ImPACT’s Verbal Memory, Visual Memory, and VMS outcome scores (all P < .001). VMS improved for White athletes between T1–T2 (P = .02) and T3 (P = .006). Black athletes had improved VMS scores between T1–T3 (P = .015) and T2–T3 (P = .005). A between-group difference was observed for VMS at T2 (P = .004). Conclusions: There was 1 small and not clinically significant difference between groups for the VMS score at T2. Overall, groups performed consistently or improved upon their baseline balance, cognition, and symptom outcome scores at clinically relevant time points following a SRC.

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.

A sport-related musculoskeletal injury carries substantial consequences. It is essential to individualize management of these injuries with a model optimizing goal-oriented rehabilitation. A major challenge is to link a patient’s goal for returning to sport with the restoration of performance assessed through the rehabilitation process. Even more challenging is that the demanded movement competence is a moving target based on the type of sport and level of competition the athlete seeks to return to. Currently, no single standardized test battery can elucidate a patient’s readiness to return to their desired sport at their desired level. We propose a clinical framework to link the assessed capacity (AC) of patients and the demanded competence (DC) of a sport/recreational activity to develop a readiness score (the AC-DC score). The AC-DC score provides a starting point for exploring the critical elements in the decision-making process surrounding the return-to-sport continuum.

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.

Daily living activities present a diverse array of task and environmental constraints, highlighting the critical role of adapting gait initiation (GI) for an individual’s quality of life. This study investigated the effects of GI directions, obstacle negotiation, and leg dominance on anticipatory postural adjustments and stepping kinematics. Fourteen active, young, healthy individuals participated in GI across 4 directions—forward, medial 45°, lateral 45°, and lateral 90°—with variations in obstacle presence and leg dominance. Results revealed a consistent decreasing trend in maximum center of pressure displacement, anticipatory postural adjustment duration, step distance, and swing leg velocity with lateral shifts in GI directions, yet the step duration and swing leg heel trajectory were not affected by GI directions except in lateral 90° GI. Center of pressure displacements were intricately scaled to directional propulsive forces generation, and the stepping kinematics were influenced by the directional modifications in movements. With obstacles, modifications in anticipatory postural adjustment metrics and stepping kinematics reflected the obstacle clearance movements. The dominant leg GI exhibited longer step durations and greater movement variability in medial 45° GI. The current investigation of GI factors expands our existing understanding of GI dynamics and offers valuable insights applicable to fall prevention and gait rehabilitation strategies.