Jack Williams

All Publications

• Sex-Based Differences in Patient-Reported Outcome Measures Are Not Present Three Months After ACL Reconstruction. Journal of clinical medicine Alfayyadh, A., Williams, J. R., Neal, K., Khandha, A., Snyder-Mackler, L., Buchanan, T. S. 2026; 15 (2)

  Abstract

  Background: Patient-reported outcome measures (PROMs) provide important insights into recovery after anterior cruciate ligament reconstruction (ACLR). Previous research suggests that males and females recover differently after ACLR, with females reporting greater pain, slower functional gains, and lower psychological readiness at later stages of rehabilitation. However, it is unknown if patient-reported outcomes differ by sex early after ACLR. To address this gap, we conducted a cross-sectional analysis comparing patient-reported outcome measures between sexes three months after ACLR. We hypothesized that females would report worse PROMs compared to males. Methods: This cross-sectional analysis used data from a prospectively maintained ACL reconstruction cohort. Fifty-six individuals (female: 23 and male: 33) with primary, unilateral ACLR completed PROMs three months after surgery. These PROMs included the Knee Injury and Osteoarthritis Outcome Score (KOOS; Symptoms, Pain, Activities of Daily Living, Sport and Recreation, Quality of Life), International Knee Documentation Committee (IKDC) subjective score, Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS), Anterior Cruciate Ligament-Return to Sport After Injury (ACL-RSI), and the Tampa Scale of Kinesiophobia (TSK). All outcomes were expressed on a 0 to 100 percent scale, with higher scores indicating better outcomes, except for TSK, where lower scores indicated better outcomes. Normality was assessed within sex, using the Shapiro-Wilk test. Two-tailed independent-samples t-tests with Welch correction were used for approximately normal variables; otherwise, Mann-Whitney U tests were utilized (α = 0.05). Several outcomes had limited statistical power to detect MCID-sized differences, and findings for these measures should be interpreted cautiously. Results: No significant differences between sexes were found for any of the PROMs. Males trended towards having better KOOS Sport and Recreation and IKDC, but these were not statistically significant, and the effect sizes were small-to-moderate. Conclusions: No statistically significant sex-based differences were detected in PROMs at approximately 3 months after ACLR, indicating that any sex-related divergences between these measures may not occur until later in recovery.

  View details for DOI 10.3390/jcm15020680

  View details for PubMedID 41598617

  View details for PubMedCentralID PMC12841943

• Ankle Exoskeleton Resistance Training May Improve Older Adult Plantarflexor Strength and Mobility: A Pilot Evaluation. Journal of biomechanics Williams, J. R., Hylin, J. C., Fang, Y., Lerner, Z. F. 2025; 194: 113071

  Abstract

  Older adults exhibit declining mobility with age, partly because ankle plantarflexor strength and function, which are crucial for propulsion, are diminished. Exoskeletons hold potential as task-specific resistance training tools that may lead to improved mobility by promoting functional neuromuscular control in addition to strength. Thus, this pilot study assessed the efficacy of an ankle exoskeleton resistance training paradigm on improving plantarflexor strength and mobility among older adults. Eight participants (age: 76 ± 5 years) completed twelve sessions of biofeedback-informed ankle exoskeleton resistance training over four weeks. Each session consisted of twenty minutes of treadmill walking with exoskeleton resistance and plantar pressure-based biofeedback. Prior to and following training, individuals completed plantarflexor strength testing, overground mobility assessments, and treadmill-based biomechanical assessments. Following resistance training, participants had increased plantarflexor muscle strength (+38%, p < 0.001), greater habitual (+13%, p < 0.001) and fastest (+9%, p = 0.005) overground walking speeds, and further six-minute walk test distances (+11%, p = 0.025). While walking on a treadmill at the same speed as their pre-assessment visit, individuals had increased peak ankle plantarflexion angles (+3.6°, p = 0.037) and hip range of motion (+1.6°, p = 0.005), but no differences in the cost of transport (-2%, p = 0.690), peak anterior ground reaction force (+5%, p = 0.285), peak ankle power (+2%, p = 0.757), and peak hip power (-7%, p = 0.348). A randomized trial investigating the full potential of this paradigm and the biomechanical mechanisms responsible for improved mobility warrants further exploration.

  View details for DOI 10.1016/j.jbiomech.2025.113071

  View details for PubMedID 41260122