Single Leg Step Research Articles

Functional performance profile of Under-20 soccer athletes from a Brazilian first division team during the COVID-19 pandemic: A descriptive study

BackgroundThe COVID-19 pandemic led to widespread social isolation and the suspension of sports activities, significantly impacting the physical and psychological performance of athletes worldwide, particularly soccer players. This study aims to evaluate the effects of pandemic-related training suspensions on the functional performance of U-20 soccer players from a first-division club in Rio de Janeiro. MethodsForty-one male U-20 soccer players were assessed during the preseason (PS) periods of 2020 and 2021. The following functional tests were performed: Single Leg Step Down (STEP DOWN), Ankle Mobility Test (LUNGE), Y-Balance Test (YBT), and Single Leg Bridge Test (BRIDGE). Comparisons were made between seasons and against established cutoff values. ResultsMost athletes demonstrated moderate-to-good performance in the functional tests during PS-20. However, in PS-21, the players showed significantly improved performance in the LUNGE test (P = 0.001) but a decline in YBT performance (P = 0.009). Specifically, 68% and 21% of the U-20 players exhibited moderate-to-good performance in LUNGE and YBT, respectively, in PS-21. ConclusionAfter a period of restricted social and sports activities due to the COVID-19 pandemic, most U-20 soccer players experienced changes in their functional test performance. These findings highlight the need for medical and health professionals working with soccer teams to carefully plan exercise and rehabilitation programs during periods of activity restrictions.

Lumbopelvic Stability during a Single Leg Step Down Predicts Elbow Varus Torque during Baseball Pitching.

During a baseball pitch, energy is transferred from the lower extremities through the lumbopelvic junction to the upper extremity. Reduced lumbopelvic stability has been associated with elbow injuries, but the mechanisms are unclear. Characterize the predictive ability of lumbopelvic stability on elbow varus torque during a baseball pitch. Cross-Sectional. Facilities at NCAA Division 1 universities. NCAA Division 1 baseball players (N=44; 19.6+1.3yrs). Pitchers completed a warm-up and then threw ten fastballs from a mound to a catcher. During the pitches, elbow varus torque was recorded using an inertial measurement unit and ball velocity was recorded with a radar gun. Participants also completed a single leg step down (SLSD) task with and without a cognitive Stroop, while triplanar pelvic and trunk kinematics were recorded by inertial measurement units. Statistical analysis consisted of a cluster analysis, principal component analysis (PCA), and a multivariate logistic regression model. Cluster analysis revealed 2 clusters: Low Torque-High Velocity and High-Torque-Low Velocity. The PCA analysis revealed 4 patterns of variability (principal components) during the SLSD: 1-sagittal plane, 2-transverse plane, 3-frontal plane trail limb, and 4-frontal plane lead limb. Logistic regression indicated increased transverse plane trunk and pelvis motion predicted higher odds of belonging to the High Torque-Low Velocity cluster; trunk [OR=2.9 (95%CI:1.1,8.0), p=0.036] and pelvis [OR=2.6 (95%CI:1.1,6.0), p=0.031]. Lumbopelvic movement assessed during the SLSD can identify deficits that relate to high elbow torque-low ball velocity during the baseball pitch. Specifically, higher pelvis and trunk transverse plane motion was associated with pitchers in the High Torque-Low Velocity cluster. Our assessment of trunk and pelvis motion during a SLSD provides a method for coaches and clinicians to identify a potential risk factor related to increased elbow varus torque and decreased ball velocity.

Effects of high frequency strengthening on pain sensitivity and function in female runners with chronic patellofemoral pain

ObjectiveTo investigate the effects of a high frequency strengthening program on function, pain, and pain sensitization in female runners with chronic patellofemoral pain (PFP). DesignCross-sectional study. SettingUniversity laboratory. ParticipantsThirty female runners (mean age 32 ± 8.1 years) with chronic PFP completed an 8-week home strengthening program. Main outcome measuresVariables assessed at baseline, 8-weeks, and 12 weeks included single leg step down test (SLSD), pain, Anterior Knee Pain Scale (AKPS), University of Wisconsin Running Injury and Recovery Index (UWRI), and quantitative sensory testing. ResultsThere was large and statistically significant improvement at 8 and 12 weeks for average knee pain (ηp2 = 0.334, p < 0.001), worst knee pain (ηp2 = 0.351, p < 0.001), SLSD (ηp2 = 0.161, p = 0.001), AKPS (ηp2 = 0.463, p < 0.001), and UWRI (ηp2 = 0.366, p < 0.001). A medium to large effect and statistically significant improvement in pressure pain threshold testing was found for all local and remote structures (ηp2 range, 0.110 to 0.293, range p < 0.001 to p = 0.009) at 8 and 12 weeks. ConclusionsThere was a significant decrease in local and remote hyperalgesia via mechanical and thermal pain sensitivity testing in female runners with chronic PFP. There was a large effect and significant improvement in self-reported pain and function.

Neuromuscular and Functional Responses Among Males Trained with Free Weights vs. Machines: Implications for Injury Prevention

The purpose of this study was to compare balance, functional performance and isometric hip strength muscle among males practitioners of resistance training (RT) with Free-weights and Machines. Thirty males were recruited and separated into two groups: Free-weights (n = 15) and Machines (n = 15). Free-weights group showed a routine of RE that engaged the whole body with resistance bands, free-weights, dumbbells, and medicine balls. Conversely, machine group trained only exercises on machines. All participants underwent three tests to assess balance, functionality, and isometric muscle strength. All tests were performed in a single assessment session in the following order: Y Balance test; functional performance testing; and maximal isometric hip strength, respectively. The two-way ANOVA yielded main effects for group in the anterior (F1,22= 12.11, p &lt; .002), posteromedial (F1,22= 16.87, p &lt; .0005), posterolateral (F1,22= 15.97, p &lt; .0006) and composite (F1,22= 21.39, p &lt; .0001) in performance during YBT between free-weight vs. machines group for both legs. Single leg step down (SLSD) and Single leg hop (SLH) test demonstrating better functional performance in the free-weight group for both legs (p&lt;.001). Isometric muscle strength of hip abduction and extension showed lower in the machines when compared to free-weight group for both legs. This study showed greater balance, functional performance and isometric muscle strength of hip abduction and extension in males trained with Free-weight. Males trained with machine showed lower functional performance, balance and bilateral asymmetry of the hip extensor muscles strength and risk of injuries.

Knee Kinetics and Kinematics of Young Asymptomatic Participants during Single-Leg Weight-Bearing Tasks: Task and Sex Comparison of a Cross-Sectional Study.

This cross-sectional study aimed to describe and compare kinetic and kinematic variables of the knee joint during stair descent, single-leg step down, and single-leg squat tasks. It also aimed to investigate potential sex difference during the tasks. Thirty young asymptomatic individuals (15 males, 15 females) were assessed during the performance of single-leg weight-bearing tasks. The kinetic and kinematic data from the knee were evaluated at the peak knee moment and at peak knee flexion. Single-leg squat presented a higher peak knee moment (2.37 Nm/kg) and the greatest knee moment (1.91 Nm/kg) at knee peak angle in the frontal plane, but the lowest knee flexion (67°) than the other two tasks (p < 0.05). Additionally, the single-leg step down task presented a higher varus knee angle (5.70°) when compared to stair descent (3.71°) (p < 0.001). No substantial sex difference could be observed. In conclusion, in asymptomatic young individuals, single-leg squats presented the greatest demand in the frontal and sagittal planes. Single-leg step down demanded a greater angular displacement than stair descent in the frontal plane. We did not identify a significant difference among the sex and studied variables.

Comparison of Dynamic Knee Valgus During Single-leg Step Down Between People With and Without Pronated Foot Using Two-dimensional Video Analysis

Comparison of Dynamic Knee Valgus During Single-leg Step Down Between People With and Without Pronated Foot Using Two-dimensional Video Analysis

The Effects Of Different Blood Flow Restriction Cuff Pressures On Dynamic Knee Valgus Angles

PURPOSE: To examine the effects of two different Blood Flow Restriction (BFR) cuff pressures after three weeks of cycle training on knee stability, specifically dynamic knee valgus (DKV) angles on healthy adults. METHODS: Ten healthy participants (26 ± 3 years; 6 males; 4 females) were randomized to: BFR with 60% occlusion, and BFR with 80% occlusion while cycling in an ergometer for 15 minutes at 70 rpm, three times a week for three weeks. Knee stability was measured during a three 5-repetition single-leg step down per leg, for the right leg, from a 30-centimeter firm and stable platform. Participants were given one minute of rest between trials to prevent fatigue. The average knee valgus among trials was used for analysis. Valgus motion was tracked through a 10-camera motion analysis capture system (120 Hz sampling rate). Valgus was measured at the lowest achievable depth of the step down. Comparison of valgus angles were done at baseline and at three weeks. Given normally distributed data, a 2 x 2 (group by time) ANOVA was used to perform between and within-group comparisons. Statistical significance was set at an alpha of 0.05 for all comparisons. RESULTS: Although the 80% occlusion group reduced knee valgus by 2.8 degrees, between and within-group comparisons were not statistically significant for DKV. CONCLUSIONS: It appears at this point that cycling with BFR cuffs does not alter knee stability in weight bearing conditions for healthy individuals. This lack of effectiveness could be due to the short time frame between baseline and follow-up or a bigger sample size will be needed to find statistically significant differences. Future research should complement treatment techniques design to improve knee stability with BFR to explore the effects of combined interventions.

Patellar mobility and lower limb kinematics during functional activities in individuals with and without patellar tendinopathy

Study designCase-control. ObjectiveTo examine whether patients with patellar tendinopathy (PT) display greater patellar mobility and different lower body kinematics than patients without PT. BackgroundPT is a common overuse condition of the patellar tendon that can cause pain and impair function. Subjects with overuse knee problems display different hip and knee functional mechanics, specifically valgus collapse. Patellar hypermobility has not been specifically studied as a possible risk factor for PT. Methods11 patients with PT and 11 controls without PT, age 18 to 40, were studied. Using a patellofemoral arthrometer (PFA), maximal lateral and medial patellar displacement was measured. 3-D motion analysis was performed to determine lower extremity joint motions during single-leg step down and drop vertical jump tests. ResultsPatients with PT had significantly increased lateral patellar mobility compared to controls (12.21 ± 3.33 mm vs. 9.19 ± 1.92 mm, P = .017). PT patients showed significantly greater peak hip adduction with both drop vertical jump (2.7° ± 6.3° vs. -5.6° ± 4.2°; P = .003) and step down (17.0° ± 3.8° vs. 12.5° ± 4.4°, P = .024). PT patients demonstrated increased peak ankle external rotation with drop vertical jump (−21.1° ± 5.9° vs. −14.8° ± 5.5°, P = .023) and step down (−15.6° ± 5.5° vs. −9.0° ± 6.0°, P = .017). ConclusionsPatients with PT exhibit increased lateral patellar mobility, hip adduction, and ankle external rotation. The effects of increased patellar mobility deserve further study in the development, management, and prevention of PT.

Hip Abduction Strength: Relationship to Trunk and Lower Extremity Motion During A Single-Leg Step-Down Task in Professional Baseball Players.

BackgroundThe single-leg step down task (SLSD) is a clinical tool to assess movement and control of the lower extremity and trunk. Hip abduction weakness may impact movement quality during the SLSD, however the relationships between movement and strength are unclear.PurposeTo determine the relationship between hip abduction isometric strength and movement during the SLSD of trunk lean, pelvic drop, knee valgus, and hip flexion.Study DesignCross sectional, cohort studyMethodsOne hundred-eighteen Minor League baseball players (age=21.6 ± 2.0 years; n=68 pitchers, n=50 position players) participated. Bilateral hip abduction isometric strength was measured using a handheld dynamometer (HHD), and then multiplied by distance from the greater trochanter to the HHD and expressed as hip abduction torque. Video cameras captured the SLSD, with participants standing on one leg while lowering their contralateral heel to touchdown on the floor from a 0.203m (8in.) step. Trunk lean, trunk flexion, pelvic drop, knee valgus, and hip flexion were measured using Dartfish at heel touchdown. A value of 180° indicated no knee valgus. Pearson correlations examined the relationships between hip abduction torque and SLSD motions.ResultsThere were no significant correlations for position players. For pitchers, on the lead leg increased hip abduction torque weakly correlated with a decrease in knee valgus (r= 0.24, p=0.049). Also for pitchers on the trail leg, increased hip abduction torque weakly correlated with decreased pelvic drop (r= -0.28, p=0.021).ConclusionHip abduction strength contributes to dynamic control of the trunk and legs. Specifically in pitchers, hip abduction weakness was related to increased movement of the lower extremity and lumbopelvic regions during the dynamic SLSD task. These deficits could translate to altered pitching performance and injury.Levels of Evidence2.

Comparison of Foot Kinematics and Foot Plantar Area and Pressure Among Five Different Closed Kinematic Tasks.

Different closed kinematic tasks may present different magnitudes of knee abduction, foot pronation, and foot plantar pressure and area. Although there are plenty of studies comparing knee abduction between different tasks, the literature lacks information regarding differences in foot pronation and foot plantar pressure and area. We compared foot angular displacement in the frontal plane and foot plantar pressure and area among five closed kinematic tasks. Forefoot and rearfoot angular displacement and foot plantar pressure and area were collected in 30 participants while they performed the following tasks: stair descent, single-leg step down, single-leg squat, single-leg landing, and drop vertical jump. Repeated-measures analyses of variance were used to investigate differences between tasks with α = 0.05. Single-leg squat and stair descent had increased foot total plantar area compared with single-leg landing (P = .005 versus .027; effect size [ES] = 0.66), drop vertical jump (P = .001 versus P = .001; ES = 0.38), and single-leg step down (P = .01 versus P = .007; ES = 0.43). Single-leg landing and single-leg step down had greater foot total plantar area compared with drop vertical jump (P = .026 versus P = .014; ES = 0.54). There were differences also in rearfoot and midfoot plantar area and pressure and forefoot plantar pressure. Differences in foot-striking pattern, magnitude of ground reaction force, and task speed might explain these findings. Clinicians should consider these findings to improve decisions about tasks used during rehabilitation of patients with foot conditions.

Associations between isometric quadriceps strength characteristics, knee flexion angles, and knee extension moments during single leg step down and landing tasks after anterior cruciate ligament reconstruction

BackgroundIt is unclear of how peak knee extension torque and early rate of torque development outcomes are related to lower extremity loading and sagittal plane movement in activities of daily living and landing tasks despite consistent deficits after anterior cruciate ligament reconstruction. The purpose of this cross-section study is to assess the ability of quadriceps strength characteristics to predict movement patterns during a step down and single leg drop crossover hopping tasks. MethodsFifty-two individuals with a unilateral history of anterior cruciate ligament reconstruction completed three trials of the step down and crossover hopping tasks on their involved limb. Participants completed three isometric knee extension contractions at 90° knee flexion with visual feedback to assess peak knee extension torque and rate of torque development during the first 0–100 ms and 100–200 ms of the contraction. FindingsPeak knee extension torque explained the greatest variance in peak knee extension moment (R2 = 40.4%, p < 0.001) and knee flexion angle (R2 = 46.7%, p < 0.001) during the crossover hop landing. Rate of torque development (0–100 ms) was the only predictor of knee flexion angle (R2 = 19.8%, p = 0.01) at initial contact during the crossover hopping landing. Rate of torque development (100–200 ms) explained 17.6% of the variance in peak knee extension moment during the step down (p = .03). InterpretationPeak knee extension torque and early rate of torque development outcomes demonstrate limited relationships between movement of activities of daily living and sport-specific tasks. These limitations should be considered when interpreting the results of isometric strength testing in a clinical setting.

Early Objective Clinical Testing Predicts Jump Landing Mechanics Following an ACL Reconstruction: Impact for the Clinician and Return to Play Testing

Objectives:Currently, objective functional assessments are performed at the time of return to play following an anterior cruciate ligament (ACL) reconstruction. While informative, by that time the majority of organized rehabilitation has been completed, leaving little time for clinicians to address remaining impairments. Further, few objective tests have been compared to faulty movement mechanics. Identifying objective clinical tests that can be administered early during recovery from an ACL reconstruction which predict long term joint mechanics would provide sufficient time to address the underlying deficits prior to return to play testing. Thus, the purpose of this study was to determine if objective clinical tests (60 second single leg step down test and quadriceps strength) administered 3 months after surgery predicted jump landing mechanics of the knee (knee extension moment, average loading rate, vertical impact peak) at 6 months following an ACL reconstruction.Methods:29 subjects completed objective clinical testing at 3 months post operatively that included the 60 second single leg step down test and an assessment of isometric knee strength. To perform the 60 second single leg step down test, subjects performed a single leg squat by touching their heel on a scale with less than 10% of their bodyweight as many times as they could for 60 seconds while standing on an 8-inch box. Isometric knee extension strength was assessed with a hand held dynamometer secured to a table. The subject performed 4 isometric maximum isometric contractions for 5 seconds. At 6 months, performed a instrumented drop vertical landing jumping. Three trials were taken and the data were analyzed using custom Labview and Visual 3D code. The average loading rate was defined as the linear portion of the vertical ground reaction curve between 20-80% of foot contact to initial impact peak. Associations between quadriceps strength and the timed single leg step down test to knee extensor moment, average loading rate, and vertical impact peak were then made with Pearson correlation coefficients.Results:29 subjects (15 male and 14 female, Ages 20.2 ± 4.7 yrs, 24 bone patellar bone vs 5 hamstring autografts, H 1.75 ± 0.12 m, M 72.2 ± 12.1 kg) completed the study. The mean quadriceps strength was 23.3 ± 10.2 N, timed single leg step down test 20 ± 11 step downs, knee extensor moment 1.32 ± 0.54 Nm/kg, loading rate was 64.5 ± 23.6 %bodyweight/sec, and vertical impact peak 0.97 ± 0.36 %bodyweight. We found significant positive associations between 3 month quadriceps strength and knee extensor moment (r=0.442, p=0.016), average vertical loading rate (r=0.426, p=0.021), and vertical impact peak (r=0.619, p=0.000) (Figure 1). We found no significant associations between 3 month single leg step down performance and landing mechanics.Conclusion:We show the ability of a early, quick, clinically-feasible method of assessing quadriceps strength to predict joint mechanics during a drop vertical jump 6 months after ACL reconstruction. This assessment can be used to screen individuals at much earlier time point who need additional focused treatment to improve their outcomes prior to return to play testing. Further, they can give the orthopedic surgeon additional data to educate the patient and family about the need to not return to higher level activities too early and reinforces the need to be compliant with rehabilitation in order to maximize results at the time individuals begin return to sport drills.

Hamstring and Gluteal Muscle Activation During the Assessment of Dynamic Movements

Recently, sports medicine professionals have shown interest in using dynamic movement assessments to help identify biomechanical risk factors for musculoskeletal injury. Thus the purpose of this study was to propose two movements (single leg step down and single leg lateral hop) that could predict injury and determine if these proposed movements elicited muscle activation of the hamstrings and gluteals. Surface electromyography was employed and muscle activations of the hamstrings and gluteus medius muscles were classified as strong during both the single leg step down (SLSD) and single leg lateral hop (SLLH). Both the hamstrings and gluteus medius muscles are associated with musculoskeletal injury. The SLSD and SLLH cause significantly high muscle activation of both these muscle groups and should be considered for use in dynamic movement assessments.

Dry needling: Effects on activation and passive mechanical properties of the quadriceps, pain and range during late stage rehabilitation of ACL reconstructed patients

BackgroundDry needling (DN) is reported to decrease pain and improve functional movements yet the mechanisms remain unclear. Changes in muscle tone and other mechanical properties after DN could contribute to these findings but have not been investigated. ObjectivesExamine EMG and passive mechanical properties of the quadriceps muscle before and after DN. DesignEMG, MyotonPro and clinical measurements were taken pre and post DN. SettingRehabilitation department at Aspetar Sports Medicine Hospital, Qatar. Participants20 subjects reporting pain and quadriceps muscle tension. Main outcome measuresPain (VAS, measured during a single leg step down), knee flexion range, and passive mechanical properties of the superficial quadriceps were measured using the MyotonPro device. ResultsPain decreased (p < 0.01) and ROM increased in flexion (p < 0.001). EMG activity (RMS) was decreased at rest in the Vastus Lateralis (VL (p < 0.05, ES = 0.22). All other sEMG parameters were not significantly different (all p > 0.11, ES = 0.13). Passive mechanical properties were not significantly different in rectus femoris (RF) and VL. Decrement and Resistance of the Vastus Medialis (VM) were significantly decreased (p<0.05, ES>0.19). ConclusionsDN resulted in small reductions in: pain, resting activation (EMG of VL), decrement and resistance (of VM).

Differences in Lower Extremity and Trunk Kinematics between Single Leg Squat and Step Down Tasks.

The single leg squat and single leg step down are two commonly used functional tasks to assess movement patterns. It is unknown how kinematics compare between these tasks. The purpose of this study was to identify kinematic differences in the lower extremity, pelvis and trunk between the single leg squat and the step down. Fourteen healthy individuals participated in this research and performed the functional tasks while kinematic data were collected for the trunk, pelvis, and lower extremities using a motion capture system. For the single leg squat task, the participant was instructed to squat as low as possible. For the step down task, the participant was instructed to stand on top of a box, slowly lower him/herself until the non-stance heel touched the ground, and return to standing. This was done from two different heights (16cm and 24cm). The kinematics were evaluated at peak knee flexion as well as at 60° of knee flexion. Pearson correlation coefficients (r) between the angles at those two time points were also calculated to better understand the relationship between each task. The tasks resulted in kinematics differences at the knee, hip, pelvis, and trunk at both time points. The single leg squat was performed with less hip adduction (p ≤ 0.003), but more hip external rotation and knee abduction (p ≤ 0.030), than the step down tasks at 60° of knee flexion. These differences were maintained at peak knee flexion except hip external rotation was only significant in the 24cm step down task (p ≤ 0.029). While there were multiple differences between the two step heights at peak knee flexion, the only difference at 60° of knee flexion was in trunk flexion (p < 0.001). Angles at the knee and hip had a moderate to excellent correlation (r = 0.51–0.98), but less consistently so at the pelvis and trunk (r = 0.21–0.96). The differences in movement patterns between the single leg squat and the step down should be considered when selecting a single leg task for evaluation or treatment. The high correlation of knee and hip angles between the three tasks indicates that similar information about knee and hip kinematics was gained from each of these tasks, while pelvis and trunk angles were less well predicted.

Influence of Omega‐6 HUFA Status on Recovery of Muscle Performance After Fatiguing Exercise

High %n‐6 HUFA in plasma and tissues is associated with a heightened inflammatory response.PURPOSETo test if a diet that lowers the %n‐6 would be associated with less strength loss after fatiguing load carriage exercise and shorter time to recover muscle strength and performance.METHODSVolunteers were randomly assigned to either a control diet (CON; n=23; 22.5 g n‐6 and 0.2 g n‐3 HUFA/2,000 kcal) plus placebo smoothie (‐S), an experimental diet (EXP; n=25; 8.0 g n‐6 and 0.9 g n‐3 HUFA/2,000 kcal) and ‐S, or EXP plus n‐3 fortified smoothie (EXP+S; n=23; 1.9 g n‐3 HUFA) for 10 weeks. Volunteers performed a single leg step test (up to 3 sets &amp; 6 min each leg) while wearing a 20 kg vest. Maximal isometric and isokinetic torque at 60°/sec, and total work during 20 reps at 180°/sec were measured before, 5 min after the step test, and 24, 48 and 72 h of recovery.RESULTSThe step test produced a 20% (95%CI 16‐25), 19% (12‐25), and 19% (15‐27) reduction in isometric torque for EXP+S, EXP‐S, and CON, respectively, with no group x time interaction during recovery (p=0.89). A similar magnitude and pattern was observed for isokinetic torque and total work.CONCLUSIONA 10‐wk dietary manipulation that substantially lowered %n‐6 and increased %n‐3 HUFA was not associated with less fatigue or faster recovery after load carriage exercise. The views expressed in this abstract are those of the authors and do not reflect the official policy of the Dept. Army, Dept. Defense, or the U.S. Government.

What Does the Single Leg Step Down Test Measure? Contributions of Core and Hip Strength

What Does the Single Leg Step Down Test Measure? Contributions of Core and Hip Strength

Comparison of 2D and 3D kinematic changes during a single leg step down following neuromuscular training

Objectives Evaluate the effects of a weight-bearing neuromuscular training program on 2D and 3D lower extremity kinematics during a single leg step down. Design Pre-test, post-test quasi experimental. Setting Laboratory. Participants Sixty nine healthy females performed a single leg step down. The 20 females with the most medial knee orientation during this task participated in this study (20.0 yr (1.6 yr), 167.9 cm (6.0 cm), 63.2 kg (8.3 kg)). Main Outcome Measures 2D knee frontal plane projection angle (FPPA) and 3D lower extremity joint (hip and knee) and segment (pelvis and femur) angles during a single leg step down before and after training were compared using paired t-tests. Pearson correlation coefficients were used to measure the association of 2D and 3D kinematic changes following training. Results Knee FPPA decreased 4.6° after training ( P < 0.001). Hip flexion ( P < 0.001) and hip adduction ( P = 0.04) increased after training. However, no other 3D joint kinematic changes were observed. Segment angle changes included decreased femoral internal rotation ( P = 0.008) and adduction ( P = 0.08) and increased anterior pelvic tilt ( P < 0.001) and contralateral pelvic drop ( P = 0.02). The association between changes in 2D and 3D joint kinematics ranged from 0.12 to 0.34. Conclusions Exercises intended to improve altered lower extremity kinematics may reduce medial knee 2D FPPA values during a single leg step down. However, this 2D change may not be linked with any specific change in 3D joint kinematics.

Identification of Abnormal Hip Motion Associated With Acetabular Labral Pathology

Resident's case problem. Recent literature has suggested that acetabular labral pathology secondary to femoroacetabular impingement (FAI) may be a precursor to early-onset hip osteoarthritis. The purpose of this resident's case problem was to explore the extent to which abnormal movement at the hip is a possible contributor to acetabular labral pathology. The patient was a 25-year-old female with a 4-year history of anterior-medial groin pain. Based on a combination of the clinical examination and magnetic resonance imaging findings, she was given a diagnosis of acetabular labral tear by her orthopaedic surgeon and referred to a physical therapist for assessment. Movement analysis during a single-leg step down, running, and a drop jump maneuver revealed excessive hip adduction and internal rotation on the involved side, which reproduced her symptoms. Application of a hip-strapping device resulted in decreased hip adduction and internal rotation, and an immediate decrease in symptoms. The reduction in pain secondary to controlling hip motion suggests that excessive frontal and transverse plane hip motions may contribute to FAI. Accordingly, physical therapy intervention aimed at controlling and reducing hip adduction and internal rotation during activities may be indicated in patients who present with this movement pattern associated with anterior hip/groin pain.