Knee osteoarthritis (OA) is one of the leading causes of disability in the United States. Biomechanics research has expanded knowledge on knee OA presentation, progression, and treatment, with clinical practices evolving based on biomechanical discoveries. In the United States, patients with knee OA are diverse across various demographics, including age, sex, body mass index, race, and ethnicity. Given the close relationship between biomechanics research and clinical practice, it is important that biomechanical studies reflect the diverse clinical population. This scoping review evaluates the hypotheses that demographics in knee OA gait biomechanical studies are underreported and do not represent the clinical population in the United States. Research articles published between 2016 and 2024 were screened, and 58 articles were evaluated. Participant age and sex were reported in 98% of articles, while only 12% and 7% of articles reported race and ethnicity, respectively. Average study participant age and sex were representative of the clinical population. However, only a few articles reported comprehensive race and ethnicity data, so clinical comparison was inconclusive. This scoping review demonstrates the need for more comprehensive demographic reporting in knee OA gait biomechanics studies to enable a widely applicable understanding of the disease and development of optimal treatments.
Despite efforts to achieve gender equity in science, technology, engineering, and mathematics (STEM), women remain underrepresented particularly in academic leadership roles. Structured programs targeting mentoring and professional connections may strengthen mentoring skills, confidence, and social capital. This mixed-methods study evaluated the mentor component of the Biomechanics Research and Innovation Challenge program. Sixteen early-mid career women mentors completed preprogram and postprogram surveys, and 14 participated in interviews. Participants reported increased self-perceived mentoring skills (81.3%–93.8%) and confidence (75%–93.8%). Over half (56.3%) reported expanded professional networks. Thematic analysis identified 4 key themes: mentor attributes and skills, program structure and support, motivations for participation, and delivery challenges. Program structure, peer support, and training facilitated mentoring effectiveness, while time commitment and logistical barriers presented challenges. These findings demonstrate that structured mentoring programs can enhance mentoring skills, confidence, and professional networking among early-mid career women in biomechanics, highlighting their potential role in supporting career development and improving retention of women in STEM.
Propulsive trail leg ground reaction forces play an important role in transferring energy to the pelvis during baseball pitching. Traditionally, trail leg ground reaction forces have been reported as individual force components or resultants. However, propulsion depends on the coordinated contribution of both vertical and anterior shear forces. The coefficient of propulsion (CoPr), defined as the ratio of anterior shear to vertical force, provides a composite measure of trail leg force production during the stride phase. In this technical note, we compared how well of peak vertical force, peak anterior shear force, peak 2-D resultant force, and peak CoPr explained variance in pelvis kinetic energy (PKE) at stride foot contact. Thirty-seven collegiate pitchers threw fastballs from an instrumented mound. PKE was the sum of translational and rotational kinetic energies at stride foot contact. Linear regressions described variance explained in PKE by peak vertical, peak anterior shear and peak 2-D resultant forces, and peak CoPr. Peak CoPr explained greater variance in PKE ( R 2 = .32, P < .001) than peak anterior shear ( R 2 = .20, P = .005), peak vertical ( R 2 = .00, P = .920, or peak 2-D resultant forces ( R 2 = .01, P = .517). These findings suggest that considering the relationship between vertical and anterior shear forces may provide additional insight into trail leg propulsion during the stride phase of pitching.
Single-leg hop performance is widely used in clinics to assess knee function following anterior cruciate ligament injury. However, performance provides limited insight into joint-specific kinetic contributions, and the influence of repeated trials remains unclear. This study quantified the effects of hop directions (forward/vertical/backward) and repeated practice trials on performance and lower-limb joint kinetics. Forty-five injury-free participants performed 10 trials per task. Hop performance and peak moment/power/work at the hip/knee/ankle were calculated. Trials were grouped as one practice attempt and 3 blocks: I (trials 2–4), II (trials 5–7), and III (trials 8–10). Three-by-three repeated-measures analyses of variance were conducted to quantify the effects of task and practice. Backward hop demonstrated the greatest knee moment/work/power and contribution across blocks. Performance increased across blocks in forward and backward hops while remaining consistent in the vertical hop. Knee work was smaller in block I across tasks, whereas backward hop demonstrated greater knee work contribution in block II than in block I. The backward hop places greater knee emphasis, supporting its use as a knee-specific assessment. Minimal practice trials are necessary when using forward/vertical/backward hop performance to assess knee power, whereas at least 4 trials may be required for forward and vertical hops when evaluating knee work.
We evaluated the test-retest reliability of a comprehensive, multitask virtual reality (VR)-based sensorimotor assessment designed to capture and quantify aspects of body movement during standardized visuomotor, auditory, gait, oculomotor, and balance tasks. Twenty healthy adults completed 3 sessions of the Dynamic Assessment of Sensorimotor Health protocol nonconsecutive days at a university research center. Dynamic Assessment of Sensorimotor Health includes 7 VR tasks (Trail Making, Sound Localization, Tandem Gait, Reaction Board, Smooth Pursuit, Single-Leg Balance, and Target Matching Balance). Session-level performance metrics were derived from head-, hand-, and eye-tracking data, and intraclass correlation coefficients (ICC[3,1]) and session means were calculated for each metric. Reliability ranged from poor to excellent (ICC = .07 .81). Metrics from the Reaction Board (reaction time) and Target Matching Balance (head path length) tasks demonstrated highest reliability (ICC up to .81), and several measures from the Trail Making, Smooth Pursuit, and Sound Localization tasks showed fair-to-good reliability. These findings identify specific VR-derived body movement metrics that show promise tracking sensorimotor performance over time and highlight others that may require redesign or alternative processing before in longitudinal or clinical applications.
