Hip biomechanical alterations during walking in chronic ankle instability patients: a cross-correlation analysis.

Chronic ankle instability (CAI) patients often present with centrally-mediated neuromuscular adaptations. Gluteal thickness measures derived from ultrasound imaging (USI) have been correlated to hip biomechanical measures during walking among healthy individuals, however these relationships remain unexplored among CAI patients. The purpose of this study was to compare USI-derived gluteus maximus and medius thickness measures to tri-planar hip kinematics, kinetics, and gluteus medius surface electromyography (sEMG) amplitude during walking among CAI patients. Fifteen females with CAI walked on a treadmill while USI, hip tri-planar kinematics, kinetics, and sEMG were synchronously recorded. Cross-correlation analyses were conducted at 1% intervals (11-ms) from -20% to 20% in the gait cycle. Gluteus medius thickness measures were associated with frontal plane kinematics at a 99-ms lag (cross-correlation coefficient [CCF]: -0.61), transverse plane kinematics at a 66-ms lag (CCF: -0.69), and with hip kinetics at 110-ms lags (CCF: 0.51-0.55). Gluteus medius thickness measures followed sEMG amplitudes by 143-ms (CCF: 0.22). Gluteus maximus thickness was associated with sagittal kinematics at a 220-ms lag (CCF: -0.70), and thickness changes preceded sagittal kinetics at 200-ms (0.87). Compared to reference healthy data, the CAI group presented with differing lag times between USI-derived measures and hip biomechanics, suggesting neuromechanical alterations during walking.

Running behaviors, motivations, and injury risk during the COVID-19 pandemic: A survey of 1147 runners.

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.

Gait biofeedback and impairment-based rehabilitation for chronic ankle instability.

Our purpose was to analyze the effects of 4 weeks of visual gait biofeedback (GBF) and impairment-based rehabilitation on gait biomechanics and patient-reported outcomes (PROs) in individuals with chronic ankle instability (CAI). Twenty-seven individuals with CAI participated in this randomized controlled trial (14 received no biofeedback (NBF), 13 received GBF). Both groups received 8 sessions of impairment-based rehabilitation. The GBF group received visual biofeedback to reduce ankle frontal plane angle at initial contact (IC) during treadmill walking. The NBF group walked for equal time during rehabilitation but without biofeedback. Dependent variables included three-dimensional kinematics and kinetics at the ankle, knee, and hip, electromyography amplitudes of 4 lower extremity muscles (tibialis anterior, fibularis longus, medial gastrocnemius, and gluteus medius), and PROs (Foot and Ankle Ability Measure Activities of Daily Living (FAAM-ADL), FAAM-Sport, Tampa Scale of Kinesiophobia (TSK), and Global Rating of Change (GROC)). The GBF group significantly decreased ankle inversion at IC (MD:-7.3º, g = 1.6) and throughout the entire stride cycle (peak inversion: MD:-5.9º, g = 1.2). The NBF group did not have significantly altered gait biomechanics. The groups were significantly different after rehabilitation for the FAAM-ADL (GBF: 97.1 ± 2.3%, NBF: 92.0 ± 5.7%), TSK (GBF: 29.7 ± 3.7, NBF: 34.9 ± 5.8), and GROC (GBF: 5.5 ± 1.0, NBF:3.9 ± 2.0) with the GBF group showing greater improvements than the NBF group. There were no significant differences between groups for kinetics or electromyography measures. The GBF group successfully decreased ankle inversion angle and had greater improvements in PROs after intervention compared to the NBF group. Impairment-based rehabilitation combined with visual biofeedback during gait training is recommended for individuals with CAI.

Athlete Workloads During Collegiate Women's Soccer Practice: Implications for Return to Play.

CONTEXT: Athlete monitoring via wearable technology is often used in soccer athletes. Although researchers have tracked global outcomes across soccer seasons, little information exists on athlete loads during individual practice drills. Understanding these demands is important for athletic trainers in making decisions about return to play. OBJECTIVE: To provide descriptive information on total distance, total player load (PL), total distance per minute, and PL per minute for practice drill structures and game play by player position among female soccer athletes across a competitive season. DESIGN: Retrospective observational study. SETTING: National Collegiate Athletic Association Division I university. PATIENTS OR OTHER PARTICIPANTS: A total of 32 female collegiate soccer players (age = 20 ± 1 years, height = 168.75 ± 4.28 cm). INTERVENTION(S): Athletes wore a single global positioning system and triaxial accelerometer unit during all practices and games in a single soccer season. Individual practice drills were labeled by the team's strength and conditioning coach and binned into physical, technical and tactical skills and large- and small-sided competition drill structures. MAIN OUTCOME MEASURE(S): Descriptive analyses were used to assess the median total distance, total PL, total distance per minute, and PL per minute by drill structure and player position (defender, forward or striker, and midfielder) during practices and games. RESULTS: Large- and small-sided competition drills imposed the greatest percentage of workload across all measures for each position (approximately 20% of total practice), followed by physical drills. When comparing technical and tactical skills drills, we found that technical skills drills required athletes to cover a greater distance (approximately 17% for technical skills and 15% for tactical skills), and tactical skills drills required higher play intensity during practices across all positions (approximately 18% for technical skills and 13% for tactical skills). Defenders had the highest median PL outcomes of all positions during practices. CONCLUSIONS: Different practice drill types imposed various levels of demands, which simulated game play, on female soccer athletes. Athletic trainers and other clinicians may use this information in formulating objective return-to-play guidelines for injured collegiate women's soccer players.

Validation of Foot-Strike Assessment Using Wearable Sensors During Running.

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.

Increased Contact Time and Strength Deficits in Runners With Exercise-Related Lower Leg Pain.

CONTEXT: Exercise-related lower leg pain (ERLLP) is common in runners. OBJECTIVE: To compare biomechanical (kinematic, kinetic, and spatiotemporal) measures obtained from wearable sensors as well as lower extremity alignment, range of motion, and strength during running between runners with and those without ERLLP. DESIGN: Case-control study. SETTING: Field and laboratory. PATIENTS OR OTHER PARTICIPANTS: Of 32 young adults who had been running regularly (>10 mi [16 km] per week) for ≥3 months, 16 had ERLLP for ≥2 weeks and 16 were healthy control participants. MAIN OUTCOME MEASURE(S): Both field and laboratory measures were collected at the initial visit. The laboratory measures consisted of alignment (arch height index, foot posture index, navicular drop, tibial torsion, Q-angle, and hip anteversion), range of motion (great toe, ankle, knee, and hip), and strength. Participants then completed a 1.67-mi (2.69-km) run along a predetermined route to calibrate the RunScribe devices. The RunScribe wearable sensors collected kinematic (pronation excursion and maximum pronation velocity), kinetic (impact g and braking g), and spatiotemporal (stride length, step length, contact time, stride pace, and flight ratio) measures. Participants then wore the sensors during at least 3 training runs in the next week. RESULTS: The ERLLP group had a slower stride pace than the healthy group, which was accounted for as a covariate in subsequent analyses. The ERLLP group had a longer contact time during the stance phase of running (mean difference [MD] = 18.00 ± 8.27 milliseconds) and decreased stride length (MD = -0.11 ± 0.05 m) than the control group. For the clinical measures, the ERLLP group demonstrated increased range of motion for great-toe flexion (MD = 13.9 ± 4.6°) and ankle eversion (MD = 6.3 ± 2.7°) and decreased strength for ankle inversion (MD = -0.49 ± 0.23 N/kg), ankle eversion (MD = -0.57 ± 0.27 N/kg), and hip flexion (MD = -0.99 ± 0.39 N/kg). CONCLUSIONS: The ERLLP group exhibited a longer contact time and decreased stride length during running as well as strength deficits at the ankle and hip. Gait retraining and lower extremity strengthening may be warranted as clinical interventions in runners with ERLLP.

Cross-correlations between gluteal muscle thickness derived from ultrasound imaging and hip biomechanics during walking gait.

Ultrasound imaging (USI) of muscle thickness offers different insights into musculoskeletal function than kinematics, kinetics, and surface electromyography (sEMG), however it is unknown how USI-derived measures correlate to traditional measures during walking. The purpose of this study was to compare USI-derived gluteus maximus (GMAX) and medius (GMED) thickness measures to tri-planar hip kinematics and kinetics, and GMED thickness to sEMG amplitude. Fourteen females walked on a treadmill at 1.34 m/s. GMAX and GMED thickness, hip tri-planar kinematics, kinetics, and GMED sEMG were simultaneously recorded. USI-derived thickness measures were compared to other biomechanical outcomes using cross-correlation analyses, computed at each 1% (11-ms) of the gait cycle with lag times from -20% to 20%. GMED and GMAX thickness measures were most strongly correlated with hip extension and abduction angles at 150-220-ms lags (cross-correlation coefficients [CCF]: -0.34; -0.83). GMED thickness was most correlated to abduction and external rotation moments simultaneously (CCF: -0.28; -0.47). GMAX thickness and flexion moments were most strongly correlated at a 66-ms lag (CCF: 0.33). GMED sEMG amplitude was most strongly correlated to muscle thickness at a 99-ms lag (CCF: 0.39). These results elucidate the unique information provided from USI-derived measures of gluteal muscle thickness during walking.

Gluteus medius dysfunction in females with chronic ankle instability is consistent at different walking speeds.

BACKGROUND: Patients with chronic ankle instability often present with altered gait mechanics compared to ankle sprain copers. There is increasing evidence to suggest proximal neuromuscular alterations contribute to the injury etiology, however little is known about how these changes manifest during gait. The purpose of this study was to investigate ipsilateral gluteus maximus and medius functional activity ratios throughout treadmill walking at three speeds (preferred, 120% preferred, and 1.35 m per second) in chronic ankle instability patients compared to copers. METHODS: 28 females (14 chronic ankle instability, 14 copers) walked at the three gait speeds in randomized order. Ground reaction forces and 10-s gluteal ultrasound clips were simultaneously recorded. Clips were reduced using ground reaction forces to extract 55 measurement frames. Normalized gluteal thickness measures were used to determine functional activity ratios. 2 × 3 analyses of variance were run to assess group and speed effects on gluteal outcomes throughout walking using statistical parametric mapping. Post-hoc t-tests, mean differences, and Cohen's d effect sizes were assessed for significant findings (P ≤ .05). FINDINGS: The chronic ankle instability group had significantly decreased gluteus medius activity throughout the entire gait cycle when compared to the coper group, independent of gait speed (P < .001, mean differences: 0.10-0.18; d: 1.00-3.17). There were no significant group or speed main effects, nor an interaction for gluteus maximus activity. INTERPRETATION: Gluteal dysfunction throughout walking was identified in chronic ankle instability. The coper group remained within healthy reference muscle activity ranges, suggesting that proximal muscle activation alterations are associated chronic ankle impairments.

Proximal Adaptations in Chronic Ankle Instability: Systematic Review and Meta-analysis.

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.

Ultrasound Imaging of the Gluteal Muscles During the Y-Balance Test in Individuals With or Without Chronic Ankle Instability.

CONTEXT: 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. OBJECTIVE: 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. DESIGN: Cross-sectional study. SETTING: University laboratory. PATIENTS OR OTHER PARTICIPANTS: 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). INTERVENTION(S): 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. MAIN OUTCOME MEASURE(S): 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. RESULTS: 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). CONCLUSIONS: 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.

Gluteus medius activity during gait is altered in individuals with chronic ankle instability: An ultrasound imaging study.

BACKGROUND: Altered gait mechanics are frequently reported in individuals with chronic ankle instability (CAI), and increasing information suggests proximal muscle adaptations occur in this population. Ultrasound imaging (USI) offers a visual means to evaluate muscle activity during movement, and overcomes limitations of electromyography (EMG) to detect hip muscle activity. RESEARCH QUESTION: A descriptive laboratory study was conducted to determine if gluteus maximus (GMAX) and medius (GMED) muscle activity differed throughout gait in patients with CAI compared to healthy counterparts. METHODS: Twenty young adults with CAI (21.6 ± 2.4 years, 10 males) and 20 healthy participants (21.2 ± 2.8 years, 10 males) walked on a treadmill at 1.35 m/s while researchers obtained 10-second clips of bilateral USI of the GMAX and GMED. USI clips were reduced to 55 frames consisting of 11 points over five full gait cycles. Muscle thickness values during walking were normalized to quiet bipedal standing USI images to obtain functional activity ratios (FARs). FARs with 90% confidence intervals (CI) were plotted as 10% interludes from 0 to 100% of the gait cycle to compare groups and limbs. Mean differences and Cohen's d effect sizes were used to assess the extent of differences. The CAI group had decreased GMED activity bilaterally from 0 to 40% of walking gait compared to healthy counterparts with large effect sizes (d≥0.60). CAI group FARs were below quiet stance levels (FARs<1.0) throughout the entire gait cycle. There were no differences noted between groups or limbs for GMAX measures. SIGNIFICANCE: Proximal stabilizing musculature was altered bilaterally in CAI individuals compared to healthy counterparts, which may contribute to movement dysfunction. Previous studies using EMG have not detected this extent of bilateral gluteal muscle alterations in CAI groups during gait, however our findings suggest USI was able to detect significant proximal alterations during walking in this population.

Detection of Gluteal Changes Using Ultrasound Imaging During Phases of Gait in Individuals With Medial Knee Displacement.

Context: Medial knee displacement (MKD) is a common risk factor for lower-extremity injury and is related to altered gluteal muscle activity. Ultrasound imaging (USI) is a reliable means to explore mechanical muscle activity; however, no information exists regarding USI of the gluteals during gait in an MKD population. Objective: To determine differences in USI gluteal muscle activity during gait in individuals with and without MKD. Design: Descriptive laboratory study. Setting: University research laboratory. Participants: Out of 28 participants, 14 exhibiting MKD unilaterally during a single-leg squat (19.36 [1.51] y, 169.73 [7.50] cm, and 62.01 [10.57] kg; 10 females) and 14 matched non-MKD subjects (20.29 [1.73] y, 167.24 [9.07] cm, and 67.53 [16.03] kg). Interventions: Bilateral B-mode USI of the gluteus maximus (Gmax) and gluteus medius (Gmed) muscles during quiet stance, heel strike, and a 10-second treadmill walking clip. Main Outcome Measures: Gluteal thickness measures normalized to quiet stance yielded activity ratios, and percentage of muscle thickness change was assessed between heel strike and quiet stance. Differences between groups were assessed with Cohen's d effect sizes with 95% confidence intervals. Activity ratios with 90% confidence intervals plotted on 10% intervals from 0% to 100% of gait were used to compare groups and limbs. A subsample of images was measured to determine intertester reliability. Results: USI revealed decreased Gmax and Gmed percent change at heel strike (%change = -9.57% [7.15%] and -8.76% [4.26%], respectively). The MKD limb compared with the contralateral limb exhibited decreased Gmed activity ratio at 30% of gait (MKD = 0.89 [0.056]; non-MKD = 1.01 [.052]). Intertester reliability was excellent for gluteus maximus (intraclass correlation coefficient = .987 [.014]) and Gmed (intraclass correlation coefficient = .989 [.013]) measurements. Conclusions: USI highlighted gluteal activity differences of MKD limbs during gait, which may contribute to inadequate hip stabilization during this daily repetitive task. These findings potentiate the use of USI as an intervention- or screening-based visual tool.

Gait-training devices in the treatment of lower extremity injuries in sports medicine: current status and future prospects.

INTRODUCTION: This review seeks to provide synthesized information on gait-training techniques and devices applied, in four of the most prevalent chronic lower extremity injuries seen in sports medicine. AREAS COVERED: Comprehensive searches were performed in CINAHL and PubMed databases in April 2018 to identify gait-training articles in Chronic Ankle Instability (CAI), Exercise-Related Lower Leg Pain (ERLLP), Patellofemoral Pain (PFP), and Anterior Cruciate Ligament with Reconstruction (ACLR) populations. An investigator reviewed the articles and extracted data including study demographics, gait-training techniques, devices used, and primary gait-training outcomes. Fifty-eight articles were included in this review (9 CAI, 19 ERLLP, 17 PFP, 13 ACLR). Pooled analyses were performed for common outcomes within each injury category. Current evidence supports destabilization training and pressure medialization tactics for CAI (n = 9), footstrike/loading and cadence interventions for ERLLP (n = 11) and PFP (n = 7), and limb off-loading techniques for ACLR (n = 4). Commonly used devices included accelerometers (n = 6), custom gait-training footwear (n = 9), metronomes (n = 14), and pressure sensors (n = 5). EXPERT COMMENTARY: Although there are commonalities among gait-training interventions for chronic pathologies, more uniform approaches and clinical predictor rules would help identify the most appropriate interventions. Wearable sensors will continue to revolutionize gait-training and allow for ecologically valid gait-training interventions.