A Novel Intrinsic Foot Muscle Strength Dynamometer Demonstrates Moderate-To-Excellent Reliability and Validity.

Background: Intrinsic foot muscle (IFM) weakness can result in reduced foot function, making it crucial for clinicians to track IFM strength changes accurately. However, assessing IFM strength can be challenging for clinicians, as there is no clinically applicable direct measure of IFM strength that has been shown to be reliable and valid with the foot on the ground. Purpose: The purpose was to investigate the intra-rater and inter-rater reliability of a novel, budget-friendly IFM dynamometer and determine its agreement with a handheld dynamometer (HHD). The researchers also examined correlations of foot morphology and activity level to IFM strength. Study design: Descriptive Laboratory Study. Methods: Two assessors measured IFM strength of 34 healthy volunteers (4 male, 30 female; age=21.14±2.57, height=164.66 ±7.62 cm, mass=64.45±11.93 kg) on two occasions 6.62±0.78 days apart with the novel dynamometer to assess intra- and inter-rater reliability. The HHD was used to measure IFM in the first session in order to assess validity. Results: For the novel dynamometer, intra- and inter-rater reliability was moderate-to-excellent (ICC = 0.73 - 0.95), and the majority of the strength tests were within the 95% limits of agreement with the HHD. Wider foot morphology and a higher number of days walking over the prior seven days had small but significant correlations with IFM strength (dominant foot r = 0.34, non-dominant foot r = 0.39; r = -0.33, -0.39 respectively). Conclusion: This novel IFM dynamometer is a budget-friendly ($75) tool that was shown to be reliable and valid in a healthy population. Levels of evidence: Level 3©The Author(s).

The Effects of Minimalist Shoes on Plantar Intrinsic Foot Muscle Size and Strength: A Systematic Review.

Minimalist shoes are proposed to prevent injury and enhance performance by strengthening intrinsic foot muscles, yet there is little consensus on the effectiveness of minimalist shoes in increasing muscle strength or size. This systematic review assesses using minimalist shoes as an intervention on changes in plantar intrinsic foot muscle size and strength. PubMed, CINHAL, Scopus, and SPORT Discus were systematically searched for articles from January 2000 to March 2022. Studies were included if they had an intervention of at least 2 weeks with a control group and examined the effect of minimalist shoes on plantar intrinsic foot strength or size (either volume, cross-sectional area, or thickness). Nine studies were included. There were significant increases and percent changes in foot muscle strength, volume, cross-sectional area, and thickness. Strength increased between 9-57%, and size increased between 7.05-10.6%. Minimalist shoes may effectively increase intrinsic foot muscle size and strength in healthy individuals, and they may also be more convenient than implementing time-intensive physical therapy programs. Future research is needed to explore using minimalist shoes as an intervention in clinical populations who would benefit from increased IFM strength and function. It will also be vital to improve upon IFM assessment methods.

Predicting Anterior Cruciate Ligament Reinjury From Return-to-Activity Assessments at 6 Months Postsurgery: A Prospective Cohort Study.

CONTEXT: Return-to-activity (RTA) assessments are commonly administered after anterior cruciate ligament reconstruction (ACLR) to manage the patient's postoperative progressions back to activity. To date, few data are available on the clinical utility of these assessments to predict patient outcomes such as secondary anterior cruciate ligament (ACL) injury once the athlete has returned to activity. OBJECTIVE: To identify the measures of patient function at 6 months post-ACLR that best predict RTA and second ACL injury at a minimum of 2 years after ACLR. DESIGN: Prospective cohort study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 234 patients with primary, unilateral ACLR completed functional assessments at approximately 6 months post-ACLR. Of these, 192 (82.1%) completed follow-up at ≥2 years post-ACLR. MAIN OUTCOME MEASURE(S): The 6-month functional assessments consisted of patient-reported outcomes, isokinetic knee-flexor and -extensor strength, and single-legged hopping. We collected RTA and secondary ACL injury data at ≥2 years after ACLR. RESULTS: Of the patients who were able to RTA (n = 155), 44 (28.4%) had a subsequent ACL injury, 24 (15.5%) to the ipsilateral graft ACL and 20 (12.9%) to the contralateral ACL. A greater proportion of females had a secondary injury to the contralateral ACL (15/24, 62.5%), whereas a greater proportion of males reinjured the ipsilateral ACL graft (15/20, 75.0%; P = .017). Greater knee-extension symmetry at 6 months increased the probability of reinjury (B = 0.016, P = .048). Among patients with RTA at <8 months, every 1% increase in quadriceps strength symmetry at 6 months increased the risk of reinjury by 2.1% (B = 0.021, P = .05). Among patients with RTA at >8 months, every month that RTA was delayed reduced the risk of reinjury by 28.4% (B = -0.284, P = .042). Descriptive statistics of patient function stratified between the early and delayed RTA groups can be found in the Supplemental Table (available online at http://dx.doi.org/10.4085/1062-6050-0407.20.S1). CONCLUSIONS: Patients with more symmetric quadriceps strength at 6 months post-ACLR were more likely to experience another ACL rupture, especially those who returned to sport at <8 months after the index surgery. Clinicians should be cognizant that returning high-functioning patients to activity at <8 months post-ACLR may place them at an increased risk for reinjury.

Intrinsic foot muscle size and quality in a single leg weight bearing position across foot posture types in individuals with Patellofemoral Pain compared to healthy.

OBJECTIVE: To identify if any differences exist in IFM size and quality in single leg weight bearing position between healthy and PFP participants based on foot posture. DESIGN: Cross-sectional, matched case-comparison study SETTING: University Laboratory Setting PARTICIPANTS: 35 PFP (age:20.46 ± 3.79yrs, mass:73.28 ± 26.58 kg, height:170.80 ± 11.91 cm) and 35 healthy (age:20.40 ± 3.16yrs, mass:64.76 ± 11.52 kg, height:169.55 ± 9.10 cm) participants METHODS: After measuring Foot Posture Index (FPI), ultrasound images (USI) of Abductor Hallucis (AH), Flexor Digitorum Brevis (FDB) and Quadratus Plantae (QP) were taken in a single limb weight bearing position. Cross-sectional area (CSA) and echogenicity were measured on the USI. RESULTS: FPI was not different between groups (PFP:2.34 ± 3.76, Healthy:2.34 ± 3.10, 9 pronated and 26 non-pronated in both groups). AH CSA was smaller in PFP than healthy group (PFP:0.030 ± 0.01 cm (Smith et al., 2018)/kg, Healthy:0.042 ± 0.01 cm (Smith et al., 2018)/kg, P < 0.001) with a large effect (d = -1.20(-1.71, -0.69). There were no other significant group main effects or group-by-FP interactions in AH/FDB/QP CSA or echogenicity. CONCLUSION: AH CSA was smaller in PFP than healthy controls, but no difference in CSA or echogenicity of FDB/QP exist, as well as no difference in foot posture between groups. While single limb weight bearing, the PFP group presented with a smaller IFM which provides eccentric control of medial longitudinal arch, which may have implications up the chain during weight bearing functional tasks.

Quantification of Workload and Wellness Measures in a Women's Collegiate Volleyball Season.

The purpose of this paper was to quantify internal and external loads completed by collegiate volleyball athletes during a competitive season. Eleven players were sampled (using accelerometers and subjective wellness surveys) during the practice (n = 55) and game (n = 30) sessions over the 2019 season. Longitudinal data were evaluated for trends across the preseason, non-conference play, and conference play periods. Data were also analyzed with respect to positional groups. Longitudinal analysis of accelerometer data showed higher workload demand during practices than games. Positional group differences were most when evaluating jump count and height. Setters accrued over twice as many jumps in a practice than during a game and had similar overall jump counts in practice to attacking positions. Average team wellness values varied with time in the season, especially during times of congested travel. This is the first study to look at both game and practice workload and wellness measures in collegiate women's volleyball. The results suggest athlete monitoring can be used to understand the demands of volleyball and used in the future to enhance practice and recovery day design to optimize athlete well-being.

Quadriceps Oxygenation During Exercise in Patients With Anterior Cruciate Ligament Reconstruction.

CONTEXT: The causes of persistent muscle weakness after anterior cruciate ligament reconstruction (ACLR) are not well known. Changes in muscle oxygenation have been proposed as a possible mechanism. OBJECTIVE: To investigate changes in quadriceps muscle oxygenation during knee extension in ACLR-involved and ACLR-uninvolved limbs. DESIGN: Case-control study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 20 individuals: 10 patients with primary, unilateral ACLR (7 women, 3 men; age = 22.90 ± 3.45 years, height = 170.81 ± 7.93 cm, mass = 73.7 ± 15.1 kg) and 10 matched control individuals (7 women, 3 men; age = 21.50 ± 2.99 years, height = 170.4 ± 10.7 cm, mass = 68.86 ± 9.51 kg). INTERVENTION(S): Each participant completed a single data-collection session consisting of 5-second isometric contractions at 25%, 50%, and 75% of the volitional maximum followed by a 30-second maximal isometric knee-extension contraction. MAIN OUTCOME MEASURE(S): Oxygenated hemoglobin (O2Hb) measures in the reconstructed thigh were continuously recorded (versus the uninvolved contralateral limb as well as the nondominant thigh of healthy control individuals) using 3 wearable, wireless near-infrared spectroscopy units placed superficially to the vastus medialis, vastus lateralis, and rectus femoris muscles. Relative changes in oxygenation were ensemble averaged and plotted for each contraction intensity with associated 90% CIs. Statistical significance occurred where portions of the exercise trials with CIs on the O2Hb graph did not overlap. Effect sizes (Cohen d, 90% CI) were determined for statistical significance. RESULTS: We observed less relative change in O2Hb in patients with ACLR than in healthy control participants in the rectus femoris at 25% (d = 2.1; 90% CI = 1.5, 2.7), 50% (d = 2.8; 90% CI = 2.6, 2.9), and 75% (d = 2.0; 90% CI = 1.9, 2.2) and for the vastus medialis at 75% (d = 1.5; 90% CI = 1.4, 1.5) and 100% (d = 2.6; 90% CI = 2.5, 2.7). Less relative change in O2Hb was also noted for the vastus medialis in ACLR-involved versus ACLR-uninvolved limbs at 100% (d = 2.62; 90% CI = 2.54, 2.70). CONCLUSIONS: Quadriceps muscle oxygenation during exercise differed between patients with ACLR and healthy control individuals. However, not all portions of the quadriceps were affected uniformly across contraction intensities.

Effects of 4-week impairment-based rehabilitation on jump-landing biomechanics in chronic ankle instability patients.

OBJECTIVE: To determine effects of 4-weeks of impairment-based rehabilitation on lower extremity neuromechanics during jump-landing. DESIGN: Descriptive laboratory study. PARTICIPANTS: Twenty-six CAI subjects (age = 21.4 ± 3.1 sex=(M = 7,F = 19), height = 169.0 ± 8.8 cm, weight = 71.0 ± 13.8 kg) completed 15 jump-landing trials prior to and following 12 supervised rehabilitation sessions. MAIN OUTCOME MEASURES: Frontal and sagittal lower extremity kinematics and kinetics and sEMG amplitudes (anterior tibialis, peroneus brevis, peroneus longus, and medial gastrocnemius). Means and 90% confidence intervals (CIs) were calculated for 100 ms prior to and 200 ms following ground contact. Areas where pre- and post-rehabilitation CIs did not overlap were considered significantly different. Kinematic and kinetic peaks and kinematic excursion were compared with paired t-test (P ≤ 0.05). RESULTS: Following rehabilitation, CAI subjects exhibited less ankle (2.1° (0.8, 3.4), P < 0.01) and hip (2.0° (0.5, 3.7), P = 0.01) frontal plane excursion and lower peak hip abduction (2.5° (0.0, 5.0), P = 0.05). There was less ankle (5.0° (1.7, 8.3), P < 0.01) and knee (3.4° (0.8, 6.0), P = 0.01) sagittal plane excursion following rehabilitation. There was decreased peroneus longus activity from 9 ms to 135 ms post ground contact and decreased peak plantar flexion moment (0.08 N∗m/kg (0.01, 0.13), P = 0.02) following rehabilitation. CONCLUSION: Progressive impairment-based rehabilitation resulted in reductions in kinematic excursion and peroneus longus muscle activity, suggesting a more efficient landing strategy.

Visuomotor therapy modulates corticospinal excitability in patients following anterior cruciate ligament reconstruction: A randomized crossover trial.

BACKGROUND: Corticospinal adaptations have been observed following anterior cruciate ligament reconstruction around the time of returning to activity. These measures have been related to quadriceps strength deficits. Visuomotor therapy, combining motor control tasks with visual biofeedback, has been shown to increase corticospinal excitability. The purpose of this study was to assess the immediate changes of corticospinal excitability following a single session of visuomotor therapy in patients following anterior cruciate ligament reconstruction. METHODS: This was a single blinded, sham-controlled crossover study. Ten patients following ACLR (8 Female, 26.1(6.2) years) completed assessments of quadriceps strength at approximately 4- and 6-months following anterior cruciate ligament reconstruction. At 6-months, quadriceps motor evoked potentials were assessed at 80%, 90%, 100%, 110%, 120%, 130%, 140%, and 150% of the patient's active motor threshold. Patients were randomized to receive a single session of visuomotor therapy(active) or passive motion(sham). Quadriceps motor evoked potentials were reassessed for treatment effect. Following a one-week washout period, all patients received the crossover intervention. FINDINGS: Moderate to large increases in motor response following visuomotor therapy 90%(P = .008, r = 0.60), 110%(P = .038, r = 0.46), 120%(P = .021, r = 0.52), 130%(P = .021, r = 0.52), 140%(P = .008, r = 0.60) and 150%(P = .021, r = 0.52) of the active motor threshold were found. Moderate increases in motor response was observed following the passive motion at 80% of the active motor threshold(P = .028, r = 0.49). INTERPRETATION: A single session of visuomotor therapy was found to increase quadriceps corticospinal motor response greater than the response to sham therapy. Visuomotor therapy is a potential supplement to quadriceps rehabilitation programs when upregulation of corticospinal excitability is indicated.

Athletic Trainers' Perceptions of Treating and Managing Patients With Ankle Sprains.

CONTEXT: Ankle sprains are common occurrences in athletic and general populations. High volumes of ankle sprains elevate the clinical burden on athletic trainers (ATs). The National Athletic Trainers' Association (NATA) published a position statement regarding the treatment and management of ankle sprains, but certain factors might affect an AT's ability to effectively implement the recommendations. OBJECTIVE: To evaluate ATs' current understanding, perceptions, and difficulties regarding the treatment, management, and long-term effects of ankle sprains. DESIGN: Cross-sectional study. SETTING: Online survey instrument. PATIENTS OR OTHER PARTICIPANTS: A total of 796 ATs (years certified = 12.1 ± 9.2) across all athletic training job settings. MAIN OUTCOME MEASURE(S): Participants completed a 38-question survey that addressed their demographic characteristics, as well as their perceptions and knowledge of the epidemiology, treatment, and management of ankle sprains. The survey was also used to document participants' patient education practices and attitudes toward the NATA position statement regarding ankle sprains, along with the challenges of and pressures against implementation. Descriptive statistics, correlations, and analyses of variance were used to analyze the data and evaluate group differences and relationships. RESULTS: Of the participants, 83% demonstrated a moderate understanding of fundamental ankle sprain epidemiology. Group differences regarding patient education were seen by education levels, years certified, and job setting. Overall, 38.1% of ATs were either unsure or unaware of the NATA position statement, but those who were aware rated its usefulness at 3.89 on a scale of 1 to 5, with 1 being not useful at all; 3, neutral; and 5, very useful. On average, 1.9 ± 0.88 challenges to implementing effective treatment practices were documented, and 2.0 ± 0.95 pressures to return athletes to play after ankle sprain were reported. CONCLUSIONS: Nearly 40% of the ATs were either unaware or unsure of the current recommendations regarding how patients with ankle sprains are treated, which could affect how care is delivered.

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.

Lower Extremity Biomechanics During a Drop-Vertical Jump and Muscle Strength in Women With Patellofemoral Pain.

CONTEXT: Patellofemoral pain (PFP) is one of the most prevalent knee conditions observed in women. Current research suggests that individuals with PFP have altered muscle activity, kinematics, and kinetics during functional tasks. However, few authors have examined differences in lower extremity biomechanics in this population during the drop-vertical jump (DVJ). OBJECTIVE: To determine how lower extremity electromyography, kinematics, and kinetics during a DVJ and lower extremity isometric strength differed between women with and those without PFP. DESIGN: Cross-sectional study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Fifteen healthy women (age = 20.23 ± 1.39 years, height = 169.32 ± 5.38 cm, mass = 67.73 ± 9.57 kg) and 15 women with PFP (age = 22.33 ± 3.49 years, height = 166.42 ± 6.01 cm, mass = 65.67 ± 13.75 kg). INTERVENTION(S): Three trials of a DVJ. MAIN OUTCOME MEASURE(S): Surface electromyography, kinematics, and kinetics were collected simultaneously during a DVJ. Lower extremity strength was measured isometrically. Independent-samples t tests were performed to assess group differences. RESULTS: Normalized muscle activity in the vastus medialis (healthy group = 120.84 ± 80.73, PFP group = 235.84 ± 152.29), gluteus maximus (healthy group = 43.81 ± 65.63, PFP group = 13.37 ± 13.55), and biceps femoris (healthy group = 36.68 ± 62.71, PFP group = 11.04 ± 8.9) during the landing phase of the DVJ differed between groups. Compared with healthy women, those with PFP completed the DVJ with greater hip internal-rotation moment (0.04 ± 0.28 N/kg versus 0.06 ± 0.14 N/kg, respectively) and had decreased knee-flexion excursion (76.76° ± 7.50° versus PFP = 74.14° ± 19.85°, respectively); they took less time to reach peak trunk flexion (0.19 ± 0.01 seconds versus 0.19 ± 0.02 seconds, respectively) and lateral trunk flexion (0.12 ± 0.07 seconds versus 0.11 ± 0.04 seconds, respectively). CONCLUSIONS: During the DVJ, women with PFP had increased hip internal-rotation moment and decreased knee-flexion excursion with less time to peak trunk flexion and lateral flexion. Muscle activation was increased in the vastus medialis but decreased in the gluteus maximus and biceps femoris. This suggests that altered motor-unit recruitment in the hip and thigh may result in changes in biomechanics during a DVJ that are often associated with an increased risk of injury.

Effects of midfoot joint mobilization on ankle-foot morphology and function following acute ankle sprain. A crossover clinical trial.

BACKGROUND: Midfoot joint impairment is likely following lateral ankle sprain (LAS) that may benefit from mobilization. OBJECTIVE: To investigate the effects of midfoot joint mobilizations and a one-week home exercise program (HEP) compared to a sham intervention and HEP on pain, patient-reported outcomes (PROs), ankle-foot joint mobility, and neuromotor function in young adults with recent LAS. METHODS: All participants were instructed in a stretching, strengthening, and balance HEP and were randomized a priori to receive midfoot joint mobilizations (forefoot supination, cuboid glide and plantar 1st tarsometatarsal) or a sham laying-of-hands. Changes in pain, physical, psychological, and functional PROs, foot morphology, joint mobility, pain-to-palpation, neuromotor function, and dynamic balance were assessed pre-to-post treatment and one-week following. Participants crossed-over following a one-week washout to receive the alternate treatment and were assessed pre-to-post treatment and one-week following. ANOVAs, t-tests, proportions, and 95% confidence intervals (CI) were calculated to assess changes in outcomes. Cohen's d and 95% CI compared treatment effects at each time-point. RESULTS: Midfoot joint mobilization had greater effects (p < .05) in reducing pain 1-week post (d = 0.8), and increasing Single Assessment Numeric Evaluation (immediate: d = 0.6) and Global Rating of Change (immediate: d = 0.6) compared to a sham treatment and HEP. CONCLUSION: Midfoot joint mobilizations and HEP yielded greater pain reduction and perceived improvement compared to sham and is recommended in a comprehensive rehabilitation program following LAS.

Visual Biofeedback and Changes in Lower Extremity Kinematics in Individuals With Medial Knee Displacement.

CONTEXT: Increased frontal-plane knee motion during functional tasks, or medial knee displacement, is a predictor of noncontact anterior cruciate ligament injury and patellofemoral pain. Intervention studies that resulted in a reduced risk of knee injury included some form of feedback to address aberrant lower extremity movement patterns. Research on integrating feedback into single-legged tasks and the ability to train 1 task and test another is limited. OBJECTIVE: To determine if adding real-time visual biofeedback to common lower extremity exercises would improve single-legged landing mechanics in females with medial knee displacement. DESIGN: Cohort study. SETTING: University laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty-four recreationally active females with medial knee displacement were randomized to a visual-biofeedback group (n = 12; age = 19.75 ± 0.87 years, height = 165.32 ± 8.69 cm, mass = 62.41 ± 8.91 kg) or a control group (n = 12; age = 19.75 ± 0.97 years, height = 166.98 ± 6.89 cm, mass = 59.98 ± 6.24 kg). INTERVENTION(S): Individuals in the feedback group viewed a real-time digital model of their body segments generated by Microsoft Kinect. The skeletal model changed color according to the knee-abduction angle of the test limb during the exercise tasks. MAIN OUTCOME MEASURE(S): Participants completed 3 trials of the single-legged drop vertical jump (SL-DVJ) while triplanar kinematics at the trunk, hip, knee, and ankle were collected via 3-dimensional motion capture. The feedback and control groups completed lower extremity exercises with or without real-time visual biofeedback, respectively. After the intervention, participants completed 3 additional trials of the SL-DVJ. RESULTS: At baseline, the feedback group had 3.83° more ankle eversion than the control group after initial contact. After the intervention, the feedback group exhibited 13.03° more knee flexion during the flight phase of the SL-DVJ and 6.16° less knee abduction after initial contact than the control group. The feedback group also demonstrated a 3.02° decrease in peak knee-abduction excursion compared with the baseline values (P = .008). CONCLUSIONS: Real-time visual biofeedback immediately improved faulty lower extremity kinematics related to knee-injury risk. Individuals with medial knee displacement adjusted their movement patterns after a single training session and reduced their medial knee motion during a dynamic task.

Sex affects gait adaptations after exercise in individuals with anterior cruciate ligament reconstruction.

BACKGROUND: Osteoarthritis after anterior cruciate ligament reconstruction has been linked with changes in gait. Individuals with reconstruction demonstrate gait changes after exercise, however there is no information on altered gait after exercise based on sex. The purpose of this study was to examine the association of sex on changes in running gait after exercise in individuals with reconstruction compared to healthy. METHODS: Forty females (22 reconstructed) and 22 men (11 reconstructed) ran before and after exercise. Triplanar lower extremity kinematics and kinetics were measured on the involved limb. Data were reduced to 0-100% of gait. Change scores were calculated for each 1% with 90% confidence intervals. Mean differences were calculated for all significant differences. FINDINGS: After exercise, females with reconstruction increased knee valgus (1.81°), knee external rotation (2.02°), lateral trunk flexion (1.24°) and trunk rotation (2.15°) compared to healthy females. Females with reconstruction increased knee extension moment (0.07 Nm/kg), knee abduction moment (0.08 Nm/kg), hip extension moment (0.14 Nm/kg) and hip internal rotation moment (0.04 Nm/kg) compared to healthy females. After exercise, males with reconstruction decreased knee varus (-4.83°), hip adduction (-1.99°), and hip internal rotation (-4.44°), however increased lateral trunk flexion (1.94°) compared to healthy males. Males with reconstruction increased knee extension moment (0.07 Nm/kg), knee adduction moment (0.31 Nm/kg), knee internal rotation moment (0.13 Nm/kg), hip flexion moment (0.17 Nm/kg), and hip external rotation moment (0.05 Nm/kg) compared to healthy males. INTERPRETATION: Males with reconstruction increased hip loading while women with reconstruction increased trunk motion post-exercise. Sex should be considered when evaluating response to exercise after reconstruction.

Measures of Agility and Single-Legged Balance as Clinical Assessments in Patients With Anterior Cruciate Ligament Reconstruction and Healthy Individuals.

CONTEXT: Current clinical assessments used for patients with anterior cruciate ligament reconstruction (ACLR) may not enable clinicians to properly identify functional deficits that have been found in laboratory studies. Establishing muscular-function assessments, through agility and balance tasks, that can properly differentiate individuals with ACLR from healthy, active individuals may permit clinicians to detect deficits that increase the risk for poor outcomes. OBJECTIVE: To compare lower extremity agility and balance between patients with ACLR and participants serving as healthy controls. DESIGN: Case-control study. SETTING: Controlled laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 47 volunteers in 2 groups, ACLR (9 males, 11 females; age = 23.28 ± 5.61 years, height = 173.52 ± 8.89 cm, mass = 70.67 ± 8.89 kg) and control (13 males, 12 females; age = 23.00 ± 6.44, height = 172.50 ± 9.24, mass = 69.81 ± 10.87 kg). MAIN OUTCOME MEASURE(S): Participants performed 3 timed agility tasks: Agility T Test, 17-hop test, and mat-hopping test. Balance was assessed in single-legged (SL) stance in 3 positions (straight knee, bent knee, squat) on 2 surfaces (firm, foam) with the participants' eyes open or closed for 10-second trials. Agility tasks were measured for time to completion. Eyes-open balance tasks were measured using center-of-pressure average velocity, and eyes-closed balance tasks were measured using the Balance Error Scoring System. RESULTS: For the Agility T Test, the ACLR group had slower times than the control group (P = .05). Times on the Agility T Test demonstrated moderate to strong positive relationships for unipedal measures of agility. The ACLR group had greater center-of-pressure average velocity in the SL bent-knee position than the control group. No differences were found between groups for the SL straight-knee and SL-squat balance tasks (P > .05). No differences in errors were present between groups for the eyes-closed balance tasks (P > .05). CONCLUSIONS: The ACLR group demonstrated slower bipedal agility times and decreased postural stability when assessed in an SL bent-knee position compared with the control group.

Ultrasonography of Gluteal and Fibularis Muscles During Exercises in Individuals With a History of Lateral Ankle Sprain.

CONTEXT: Individuals with a history of lateral ankle sprains (LASs) have ankle and hip neuromuscular changes compared with those who do not have a history of LAS. OBJECTIVE: To compare gluteus maximus (GMax), gluteus medius (GMed), and fibularis longus and brevis muscle activation using ultrasound imaging during tabletop exercises and lateral resistance-band walking in individuals with or without a history of LAS or chronic ankle instability (CAI). DESIGN: Cross-sectional study. PATIENTS OR OTHER PARTICIPANTS: Sixty-seven young adults (27 males, 40 females). Groups were healthy = 16, coper = 17, LAS = 15, CAI = 19. The number of previous sprains was 0 ± 0 in the healthy group, 1.1 ± 0.3 in the coper group, 2.9 ± 2.4 in the LAS group, and 5.3 ± 5.9 in the CAI group. MAIN OUTCOME MEASURE(S): Ultrasound imaging measures of fibularis cross-sectional area (CSA) were collected during nonresisted and resisted ankle eversion. Gluteal muscle thicknesses were imaged during nonresisted and resisted side-lying abduction and during lateral resistance-band walking exercises (lower leg and forefoot band placement). Separate 4 × 2 repeated-measures analyses of variance and post hoc Fisher least significant difference tests were used to assess activation across groups and resistance conditions. RESULTS: All groups demonstrated 3.2% to 4.1% increased fibularis CSA during resisted eversion compared with nonresisted. During side-lying abduction, the LAS and CAI groups displayed increased GMax thickness (6.4% and 7.2%, respectively), and all but the CAI group (-0.4%) increased GMed thickness (5.3%-11.8%) with added resistance in hip abduction. During band walking, the healthy and LAS groups showed increased GMax thickness (4.8% and 8.1%, respectively), and all groups had increased GMed thickness (3.0%-5.8%) in forefoot position compared with the lower leg position. Although the values were not different, copers exhibited the greatest amount of GMed thickness during band-walking activities (copers = 23%-26%, healthy = 17%-23%, LAS = 11%-15%, CAI = 15%-19%). CONCLUSIONS: All groups had increased fibularis CSA with resisted eversion. In side-lying hip abduction, individuals with CAI had greater GMax thickness than GMed thickness. Ultrasound imaging of fibularis CSA and gluteal muscle thickness may be clinically useful in assessing and treating patients with LAS or CAI.

The relationships between kinesiophobia and clinical outcomes after ACL reconstruction differ by self-reported physical activity engagement.

OBJECTIVES: To investigate whether relationships between kinesiophobia, lower extremity function, and patient-reported function differ by self-reported physical activity engagement after ACL reconstruction (ACLR). DESIGN: Cross-sectional. SETTING: Laboratory. PARTICIPANTS: Seventy-seven patients with a primary, unilateral ACLR. MAIN OUTCOME MEASURES: Kinesiophobia (TSK-17) was the primary outcome. Lower extremity function included quadriceps and hamstrings strength, fatigue, and hop performance. Patient-reported function included regional function (IKDC, KOOS subscales) and physical activity engagement (Godin Leisure-Time Exercise). Patients were evaluated together, then stratified by LOW and HIGH physical activity. Correlations and multiple regression analyses identified relationships between kinesiophobia and outcome measures. RESULTS: Greater kinesiophobia was associated with lesser hamstrings strength, hop performance, and patient-reported function. Greater hamstrings fatigue and lesser KOOSADL explained greater kinesiophobia in patients reporting LOW physical activity. Lesser triple hop symmetry, crossover hop distance, and IKDC explained greater kinesiophobia in patients reporting HIGH physical activity. CONCLUSIONS: Greater kinesiophobia associated with worse outcomes after ACLR. Relationships differed by self-reported physical activity engagement. Interventions that improve the ability to perform knee-related activities of daily living may be appropriate to minimize the impact of fear in less active patients, while those targeting hop performance and knee-related sport activities may be better suited for more active patients.

Impairment-Based Rehabilitation With Patterned Electrical Neuromuscular Stimulation and Lower Extremity Function in Individuals With Patellofemoral Pain: A Preliminary Study.

CONTEXT: Patellofemoral pain (PFP) is a chronic condition that presents with lower extremity muscle weakness, decreased flexibility, subjective functional limitations, pain, and decreased physical activity. Patterned electrical neuromuscular stimulation (PENS) has been shown to affect muscle activation and pain after a single treatment, but its use has not been studied in a rehabilitation trial. OBJECTIVE: To determine the effects of a 4-week impairment-based rehabilitation program using PENS on subjective function, pain, strength, range of motion, and physical activity in individuals with PFP. DESIGN: Randomized controlled trial. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 21 patients with PFP (5 males, 16 females; age = 23.4 ± 7.6 years, height = 168.0 ± 7.5 cm, mass = 69.0 ± 19.5 kg). INTERVENTION(S): Participants completed a 4-week supervised rehabilitation program in conjunction with random assignment to receive PENS or sham treatments. MAIN OUTCOME MEASURE(S): Subjective function, pain, strength, range of motion, and physical activity levels were assessed prerehabilitation and postrehabilitation. Subjective function and pain were also assessed at 6 and 12 months postrehabilitation. Repeated-measures analyses of variance and Tukey post hoc testing were conducted with α ≤ .05. We calculated Cohen d effect sizes with 95% confidence intervals. RESULTS: Both groups had statistically and clinically meaningful differences in subjective function, pain, strength, range of motion, and activity level after 4 weeks of impairment-based rehabilitation. Improved subjective function was observed in both groups at 6 and 12 months after the interventions. The PENS group had improvements in current pain for all 3 postrehabilitation times compared with baseline measures. CONCLUSIONS: An impairment-based intervention effectively improved subjective function, pain, strength, range of motion, and physical activity levels in individuals with PFP. Participants who received PENS in addition to the rehabilitation program had improved current pain at 6 and 12 months postrehabilitation compared with baseline scores. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02441712.