Introduction: Chronic ankle instability (CAI) is known to induce impairments throughout the lower quarter kinetic chain, however there is currently no synthesized information on proximal adaptations of the trunk, hip, thigh, and knee for neuromuscular and biomechanical outcomes during strength, balance, jumping, and gait among CAI patients. The purpose of this systematic review and meta-analysis was to synthesize trunk, hip, thigh and knee neuromuscular and biomechanical outcome measures during functional assessments when comparing CAI to healthy groups. Methods: Cumulative Index of Nursing and Allied Health Literature and Medical Literature Analysis and Retrieval System Online with PubMed databases were searched on June 3, 2019. Studies comparing outcomes at the trunk, hip, thigh, or knee regardless of assessment type in CAI versus healthy groups were considered for inclusion. Assessment categories were used to differentiate adaptations by assessment type after inclusion. Two independent reviewers assessed methodological quality using the Physiotherapy Evidence Database scoring criteria. Data pertaining to study methodology and primary proximal adaptation outcomes were extracted. Separate random effects meta-analyses were performed for consistently reported outcome measures. Results: Pooled estimates reflected that CAI patients had decreased triplanar isometric hip strength outcomes (P < 0.001, effect size range: 0.52–0.93). Knee kinematics did not differ from healthy groups during dynamic balance testing (P = 0.26). Few studies found CAI patients have altered knee kinematics during jumping tasks. The remaining findings were isolated to individual studies and thus inconclusive. Conclusions: The CAI groups demonstrated triplanar hip strength deficits and altered knee flexion angles during jumping assessments. Clinicians should consider proximal evaluations and interventions for CAI patients.

The COVID-19 pandemic has influenced activity behaviors worldwide. Given the accessibility of running as exercise, gaining information on running behaviors, motivations, and running-related injury (RRI) risk during the pandemic is warranted. The purpose of this study was to assess the influence of the COVID-19 pandemic on running volume, behaviors, motives, and RRI changes from the year prior to the pandemic to the timeframe during social isolation restrictions. Runners of all abilities were recruited via social media to complete a custom Qualtrics survey. Demographics, running volume, behaviors, motivations, and injury status were assessed for the year prior to the pandemic, and during social isolation measures. Descriptive statistics and Student’s t-tests were used to assess changes in running outcomes during the pandemic. Logistic regressions were used to assess the influence of demographics on running behaviors and injury. Adjusted RRI risk ratios were calculated to determine the odds of sustaining an injury during the pandemic. Alpha was set to.05 for all analyses. A total of 1147 runners (66% females, median age: 35 years) across 15 countries (96% United States) completed the survey. Runners reported increased runs per week (Mean Difference with Standard Error [MD]: 0.30 [0.05], p < .001), sustained runs (MD: 0.44 [0.05], p < .001), mileage (MD: 0.87 [0.33], p = .01), and running times of day (MD: 0.11 [0.03], p < .001) during the pandemic, yet reported less workouts (i.e. sprint intervals; MD: -0.33 [0.06], p < .001), and less motives (MD [SE]: -0.41 [0.04], p < .001). Behavior changes were influenced by running experience and age. There was 1.40 (CI: 1.18,1.61) times the RRI risk during the pandemic compared to prior to the social isolation period. The COVID-19 pandemic influenced runners’ behaviors with increased training volume, decreased intensity and motivation, and heightened injury risk. These results provide insights into how physical activity patterns were influenced by large-scale social isolation directives associated with the pandemic.

Impairments in dynamic postural control and gluteal muscle activation have been associated with the development of symptoms related to long-term injury, which are characteristic of chronic ankle instability (CAI). Ultrasound imaging (USI) provides a visual means to explore muscle thickness throughout movement; however, USI functional-activation ratios (FARs) of the gluteal muscles during dynamic balance exercises have not been investigated. To determine differences in gluteus maximus and gluteus medius FARs using USI, Y-Balance Test (YBT) performance, and lower extremity kinematics in individuals with or without CAI. Cross-sectional study. University laboratory. Twenty adults with CAI (10 men, 10 women; age = 21.70 ± 2.32 years, height = 172.74 ± 11.28 cm, mass = 74.26 ± 15.24 kg) and 20 adults without CAI (10 men, 10 women; age = 21.20 ± 2.79 years, height = 173.18 ± 15.16 cm, mass = 70.89 ± 12.18 kg). Unilateral static ultrasound images of the gluteal muscles during quiet stance and to the point of maximum YBT reach directions were obtained over 3 trials. Hip, knee, and ankle sagittal-plane kinematics were collected with motion-capture software. Gluteal thickness was normalized to quiet stance to yield FARs for each muscle in each YBT direction. We averaged normalized reach distances and obtained average peak kinematics. Independent t tests, mean differences, and Cohen d effect sizes were calculated to determine group differences for all outcome measures. The CAI group had anterior-reach deficits compared with the control group (mean difference = 4.37%, Cohen d = 0.77, P = .02). The CAI group demonstrated greater anterior gluteus maximus FARs than the control group (mean difference = 0.08, Cohen d = 0.57, P = .05). The CAI group demonstrated YBT reach deficits and alterations in proximal muscle activation. Increased reliance on the gluteus maximus during dynamic conditions may contribute to distal joint dysfunction in this population.

Wearable sensors are capable of capturing foot-strike positioning, which lends insight into landing biomechanics during running. The purpose of our study was to assess the relationship between foot-strike categorization and foot-strike angle during running to validate the sensor-derived foot-strike outcome. Twenty collegiate cross-country athletes (12 females, 8 males) ran at 2 speeds on an instrumented treadmill. RunScribe sensors were used to determine foot-strike categorizations (1–5 = rearfoot, 6–10 = midfoot, 11–16 = forefoot), and foot-strike angles were simultaneously assessed with 3-dimensional motion capture bilaterally. We calculated Pearson r correlation coefficients to compare foot-strike categorizations and angles at initial contact over 800 steps as well as sensor foot-strike identification accuracy. A strong, inverse correlation between foot-strike categorizations and foot-strike angles was present (r = −0.86, P < .001). Overall, the sensors demonstrated 78% accuracy (rearfoot = 72.5%, midfoot = 55.3%, forefoot = 95.4%). These results support the concurrent validity of the sensor-derived foot-strike measures.