Task-specific movement training improves kinematics and pain during the Y-balance test and hip muscle strength in females with patellofemoral pain.

OBJECTIVES: Task-specific movement training is a proposed intervention for patellofemoral pain aimed to optimise movement during daily tasks. Focused, progressive task practice emphasising optimal limb alignment may yield improvements in performance-based function and hip muscle strength, and transfer learnt movement patterns to untrained tasks. The purpose of this study was to determine if task-specific movement training improves performance-based function (composite score, movement, pain during movement) in an untrained task. Our secondary purpose was to test whether hip muscle strength improved following the movement training intervention. METHODS: This study was a secondary analysis of a prospective, non-randomised, within-group, double-baseline study. Twenty-three females with patellofemoral pain underwent task-specific movement training two times/week for 6 weeks. Outcomes were collected at three time points: enrolment (baseline), 6 weeks (preintervention) and 12 weeks (postintervention). A repeated measures analysis of variance tested whether the change during the intervention phase was greater than the change during the control phase. Y-balance composite score, hip and knee kinematics and pain during the Y-balance test were primary outcome measures; strength of the hip lateral rotator, abductor and extensor muscles was a secondary outcome measure. RESULTS: The change in composite score for the Y-balance test was not statistically significantly different between the intervention and control phases (p=0.16). The change during the intervention phase exceeded the change during the control phase for hip and knee kinematics and pain during the Y-balance test, with all variables improving (p<0.0001). The change during the intervention phase was greater than the control phase for hip muscle strength, with all variables improving (p<0.04). CONCLUSION: Although the Y-balance test composite score did not improve, performance-based function during an untrained task, measured by movement and pain during the test, improved following task-specific movement training. Hip muscle strength improved, despite no focused muscle strengthening. LEVEL OF EVIDENCE: Level II.

A descriptive report of the variability in 3D hip and knee kinematics during a single limb squat in women who have patellofemoral pain and visually classified dynamic knee valgus.

Objective: To describe the variability in: (1) the contributions of 3D hip and knee kinematics to the dynamic knee valgus (DKV) movement pattern during a single limb squat in women with patellofemoral pain; and (2) the 3D strategies used to reduce DKV following an intervention.Methods: Secondary analysis of a feasibility study investigating a movement training intervention. In 23 participants, 2D knee frontal plane projection angles (FPPA) and 3D hip and knee frontal and transverse plane angles at peak knee flexion were calculated during a single limb squat at pre- and post-intervention, and the change in 2D and 3D angles computed. 3D angles at pre-intervention were summed for each participant to create cumulative bar graphs. Similar graphs were created for change in 3D angles. For visual comparison, graphs were ordered by increasing knee FPPA or change in knee FPPA.Results: The knee FPPA decreased from a mean of 7.2 degrees (SD: 7.1) to a mean of -8.9 degrees (SD: 8.9) following the intervention. A large portion of DKV, and change in DKV, was due to hip adduction and knee lateral rotation, yet participants with similar knee FPPA and change in knee FPPA displayed variation in all 3D components and change in 3D components.Conclusion: People who demonstrate similar observed movement patterns during a weight-bearing task may use different 3D strategies for execution.

CONSISTENCY OF DYNAMIC KNEE VALGUS KINEMATICS AND PAIN ACROSS FUNCTIONAL TASKS IN FEMALES WITH PATELLOFEMORAL PAIN: A CROSS-SECTIONAL STUDY.

BACKGROUND AND PURPOSE: Dynamic knee valgus has been associated with patellofemoral pain (PFP) during high-level tasks, however, repeated lower-level stresses may be an alternative pain mechanism. The primary purpose of the current study was to examine the consistency of dynamic knee valgus and task-elicited pain demonstrated by females with PFP across four common functional tasks (stair ascent, stair descent, sit-to-stand, and stand-to-sit). A secondary purpose was to assess the correlation between the clinical test of single-limb squat and functional tasks. HYPOTHESIS: Females with patellofemoral pain will demonstrate a positive relationship in magnitude of dynamic knee valgus and task-elicited pain across functional tasks. Individuals who demonstrated greater dynamic knee valgus and task-elicited pain during the clinical test of single-limb squat would demonstrate greater dynamic knee valgus and task elicited pain during stair ascent/descent and sit-to-stand/stand-to-sit tasks. STUDY DESIGN: Cross-sectional study; secondary analysis of a feasibility intervention study. METHODS: Twenty-three women with patellofemoral pain (age: 21.8 SD 3.7 years; BMI: 22.2 SD 2.0 kg/m2) participated. Three-dimensional kinematic data were captured during task completion. Hip and knee frontal and transverse plane angles at 45 ° of knee flexion, and pain using a visual analog scale, were assessed during single-limb squat, stair ascent/descent, and sit-to-stand. Pearson product-moment correlation coefficients were calculated to examine between-task relationships for each variable at the pre-intervention assessment. RESULTS: Correlation coefficients between tasks ranged from 0.23-0.76 for hip frontal plane measures (7/10 significant relationships, p<0.02), 0.31-0.90 for hip transverse plane measures (7/10 significant, p<0.01), 0.87-0.95 for knee frontal plane measures (10/10 significant, p<0.01), and 0.54-0.86 for knee transverse plane measures (10/10 significant, p<0.01). Correlations spanned 0.59-0.85 for pain during tasks (10/10 significant, p<0.01). CONCLUSION: Females with patellofemoral pain demonstrated positive correlations in dynamic knee valgus kinematics and task-elicited pain across five tasks. Movement and pain during the clinical test of single-limb squat test also was correlated with movement and pain during the functional tasks of stair ascent/descent and sit-to-stand. LEVEL OF EVIDENCE: Level 2b.

Static Ankle Dorsiflexion and Hip and Pelvis Kinematics During Forward Step-Down in Patients With Hip-Related Groin Pain.

CONTEXT: The authors hypothesized that in people with hip-related groin pain, less static ankle dorsiflexion could lead to compensatory hip adduction and contralateral pelvic drop during step-down. Ankle dorsiflexion may be a modifiable factor to improve ability in those with hip-related groin pain to decrease hip/pelvic motion during functional tasks and improve function. OBJECTIVE: To determine whether smaller static ankle dorsiflexion angles were associated with altered ankle, hip, and pelvis kinematics during step-down in people with hip-related groin pain. DESIGN: Cross-sectional Setting: Academic medical center. PATIENTS: A total of 30 people with hip-related groin pain (12 males and 18 females; 28.7 [5.3] y) participated. INTERVENTION: None. MAIN OUTCOME MEASURES: Weight-bearing static ankle dorsiflexion with knee flexed and knee extended were measured via digital inclinometer. Pelvis, hip, and ankle kinematics during forward step-down were measured via 3D motion capture. Static ankle dorsiflexion and kinematics were compared with bivariate correlations. RESULTS: Smaller static ankle dorsiflexion angles were associated with smaller ankle dorsiflexion angles during the step-down for both the knee flexed and knee extended static measures. Among the total sample, smaller static ankle dorsiflexion angle with knee flexed was associated with greater anterior pelvic tilt and greater contralateral pelvic drop during the step-down. Among only those who did not require a lowered step for safety, smaller static ankle dorsiflexion angles with knee flexed and knee extended were associated with greater anterior pelvic tilt, greater contralateral pelvic drop, and greater hip flexion. CONCLUSIONS: Among those with hip-related groin pain, smaller static ankle dorsiflexion angles are associated with less ankle dorsiflexion motion and altered pelvis and hip kinematics during a step-down. Future research is needed to assess the effect of treating restricted ankle dorsiflexion on quality of motion and symptoms in patients with hip-related groin pain.

Hip Kinematics During Single-Leg Tasks in People With and Without Hip-Related Groin Pain and the Association Among Kinematics, Hip Muscle Strength, and Bony Morphology.

OBJECTIVE: To compare 3-D hip kinematics during the single-leg squat and step-down in patients with hip-related groin pain to those in asymptomatic participants, and to assess relationships among hip kinematics, muscle strength, and bony morphology. DESIGN: Controlled laboratory cross-sectional study. METHODS: Forty patients with hip-related groin pain and 40 matched, asymptomatic participants between 18 and 40 years of age participated. A handheld dynamometer was used to assess hip abductor and external rotator strength. An 8-camera motion-analysis system was used to quantify 3-D kinematics during the single-leg squat and step-down. Magnetic resonance imaging was used to quantify bony morphology. The independent t test and Mann-Whitney U test were used to assess between-group differences. Pearson coefficient correlations were used to assess relationships. RESULTS: Patients with hip-related groin pain had smaller peak hip flexion angles, smaller knee flexion angles, and lesser squat depth compared to asymptomatic participants during the single-leg squat. Among patients with hip-related groin pain, smaller hip flexion angles during the single-leg squat were associated with hip abductor weakness (r = 0.47, P≤.01). Among asymptomatic participants, smaller peak hip flexion angles during the single-leg squat were associated with less acetabular coverage (r = 0.33, P = .04) and shallow squat depth (r = 0.48, P≤.01); a smaller hip internal rotation angle during the step-down was associated with larger femoral neck shaft angle (r = -0.43, P<.01). CONCLUSION: Compared to asymptomatic participants, patients with hip-related groin pain had smaller hip and knee flexion angles and shallower squat depth during the single-leg squat. Smaller hip flexion angles were associated with hip abductor weakness among those with hip-related groin pain. J Orthop Sports Phys Ther 2020;50(5):243-251. Epub 6 Jan 2020. doi:10.2519/jospt.2020.9150.

Three dimensional kinematics of visually classified lower extremity movement patterns during a single leg squat among people with chronic hip joint pain.

OBJECTIVE: Describe the proportional occurrence of visually determined, lower extremity movement patterns (dynamic knee valgus [DKVal], neutral [NEU], dynamic knee varus [DKVar]) during a single leg squat (SLSquat) among patients with chronic hip joint pain (CHJP). Compare 3D hip and pelvic kinematics among the categories and determine whether within-session movement pattern changes are possible among those who demonstrate DKVal or DKVar. Design: Cross-sectional. Setting: Movement science laboratory. Participants: 36 patients with CHJP (18 to 40 years). Main Outcome Measures: Visually based classification of lower extremity movement and 3D kinematic angles of hip and pelvis during SLSquat, performed under usual (self-selected) and modified (therapist instruction) conditions. Results: Based on visual appraisal, 14 patients demonstrated DKVal, 22 demonstrated NEU and none demonstrated DKVar. Those with DKVal demonstrated greater hip adduction (23.5 + 5.7º vs. 16.0 + 5.7º, p < 0.001) and internal rotation (7.4 + 7.1º vs. 1.6 + 7.0º, p = 0.023) than those with NEU. Compared to the usual condition, the DKVal group demonstrated significant decrease in hip adduction (23.5 + 5.7° vs. 20.9 + 5.8°, p = 0.001) and internal rotation (7.4 + 7.1° vs. 5.3 + 7.8°, p = .050) in the modified condition. Conclusions: Patients with CHJP demonstrated 2 movement patterns, DKVal and NEU. Compared to NEU, those with DKVal demonstrated greater hip adduction and internal rotation motion and were able to make small modifications to their movement pattern with therapist instruction.

Dynamic knee valgus kinematics and their relationship to pain in women with patellofemoral pain compared to women with chronic hip joint pain.

BACKGROUND: Dynamic knee valgus (DKV) is an abnormal movement pattern visually characterized by excessive medial movement of the lower extremity during weight bearing. Differences in hip and knee kinematic components of DKV may explain the emergence of different pain problems in people who exhibit the same observed movement impairment. Using a secondary analysis of exiting data sets, we sought to determine whether hip and knee frontal and transverse plane angles during a functional task differed between women with patellofemoral pain and women with chronic hip joint pain, and the relationship between joint-specific kinematics and pain in these 2 pain populations. METHODS: In the original studies, 3-dimensional hip and knee kinematics during a single leg squat were obtained in 20 women with patellofemoral pain and 14 women with chronic hip joint pain who demonstrated visually classified DKV. Pain intensity during the squat was assessed in both groups. For the secondary analysis, kinematic data were compared between pain groups using their respective control groups as a reference. Within each pain group, correlation coefficients were used to determine the relationship between kinematics and pain during the squat. RESULTS: Hip adduction and contralateral pelvic drop were greater in those with chronic hip joint pain compared to those with patellofemoral pain (effect sizes ≥ 0.40). Greater knee external rotation (r=0.47, p=0.04) was correlated with greater knee pain in those with patellofemoral pain, while greater hip adduction (r =0.53, p =0.05) and greater hip internal rotation (r =0.55, p =0.04) were correlated with greater hip pain in those with chronic hip joint pain. CONCLUSION: Hip frontal plane motion was greater in those with chronic hip joint pain compared to those with patellofemoral pain. In both groups, greater abnormal movement at the respective joint (e.g. knee external rotation in the patellofemoral pain group and hip adduction and internal rotation in the chronic hip joint pain group) was associated with greater pain at that joint during a single leg squat.

Persistent Post-Mastectomy Pain: Risk Factors and Current Approaches to Treatment.

Persistent Post-Mastectomy Pain (PPMP) is a common condition that can follow surgeries for breast cancer, the most common cancer in women. Because of the frequency of PPMP and its potential severity, it has received increasing research attention. This manuscript reviews the recent research literature, beginning with a brief history and then relevant medical, surgical, demographic, and psychosocial risk factors. Subsequently, social, psychological, and functional sequelae that have been linked to PPMPS are considered, as is research on current pharmacological, psychological, and rehabilitative approaches to treatment. The review concludes with a discussion of directions for future research and treatment that might reduce the incidence and impact of PPMP on breast cancer survivors. PERSPECTIVE: This article describes current research literature involving mechanisms, risks, and treatments related to persistent post-mastectomy pain. Implications of research findings also are discussed for pre- and post-surgical approaches to pain management, current treatments, and promising research directions.

Immediate Effects of a Single Session of Motor Skill Training on the Lumbar Movement Pattern During a Functional Activity in People With Low Back Pain: A Repeated-Measures Study.

Background: People with low back pain (LBP) may display an altered lumbar movement pattern of early lumbar motion compared to people with healthy backs. Modifying this movement pattern during a clinical test decreases pain. It is unknown whether similar effects would be seen during a functional activity. Objective: The objective of this study was to examine the lumbar movement patterns before and after motor skill training, effects on pain, and characteristics that influenced the ability to modify movement patterns. Design: The design consisted of a repeated-measures study examining early-phase lumbar excursion in people with LBP during a functional activity test. Methods: Twenty-six people with chronic LBP received motor skill training, and 16 people with healthy backs were recruited as a reference standard. Twenty minutes of motor skill training to decrease early-phase lumbar excursion during the performance of a functional activity were used as a treatment intervention. Early-phase lumbar excursion was measured before and after training. Participants verbally reported increased pain, decreased pain, or no change in pain during performance of the functional activity test movement in relation to their baseline pain. The characteristics of people with LBP that influenced the ability to decrease early-phase lumbar excursion were examined. Results: People with LBP displayed greater early-phase lumbar excursion before training than people with healthy backs (LBP: mean = 11.2°, 95% CI = 9.3°-13.1°; healthy backs: mean = 7.1°, 95% CI = 5.8°-8.4°). Following training, the LBP group showed a decrease in the amount of early-phase lumbar excursion (mean change = 4.1°, 95% CI = 2.4°-5.8°); 91% of people with LBP reported that their pain decreased from baseline following training. The longer the duration of LBP (ß = - 0.22) and the more early-phase lumbar excursion before training (ß = - 0.82), the greater the change in early-phase lumbar excursion following training. Limitations: The long-term implications of modifying the movement pattern and whether the decrease in pain attained was clinically significant are unknown. Conclusions: People with LBP were able to modify their lumbar movement pattern and decrease their pain with the movement pattern within a single session of motor skill training.

Reduced Hip Adduction Is Associated With Improved Function After Movement-Pattern Training in Young People With Chronic Hip Joint Pain.

Study Design Ancillary analysis, time-controlled randomized clinical trial. Background Movement-pattern training (MPT) has been shown to improve function among patients with chronic hip joint pain (CHJP). Objective To determine the association among treatment outcomes and mechanical factors associated with CHJP. Methods Twenty-eight patients with CHJP, 18 to 40 years of age, participated in MPT, either immediately after assessment or after a wait-list period. Movement-pattern training included task-specific training to reduce hip adduction motion during functional tasks and hip muscle strengthening. Hip-specific function was assessed using the Modified Harris Hip Score (MHHS) and Hip disability and Osteoarthritis Outcome Score (HOOS). Three-dimensional kinematic data were used to quantify hip adduction motion, dynamometry to quantify abductor strength, and magnetic resonance imaging to measure femoral head sphericity using the alpha angle. Paired t tests assessed change from pretreatment to posttreatment. Spearman correlations assessed associations. Results There was significant improvement in MHHS and HOOS scores (P≤.02), adduction motion (P = .045), and abductor strength (P = .01) from pretreatment to posttreatment. Reduction in hip adduction motion (r = -0.67, P<.01) and lower body mass index (r = -0.38, P = .049) correlated with MHHS improvement. Alpha angle and abductor strength change were not correlated with change in MHHS or HOOS scores. Conclusion After MPT, patients reported improvements in pain and function that were associated with their ability to reduce hip adduction motion during functional tasks. Level of Evidence Therapy, level 2b. J Orthop Sports Phys Ther 2018;48(4):316-324. doi:10.2519/jospt.2018.7810.

A feasibility study of a novel, task-specific movement training intervention for women with patellofemoral pain.

OBJECTIVE: To investigate whether a novel, task-specific training intervention that focused on correcting pain-producing movement patterns was feasible and whether it would improve hip and knee kinematics, pain, and function in women with patellofemoral pain. DESIGN: Prospective, non-randomized, within-group, double baseline, feasibility intervention study. SUBJECTS: A total of 25 women with patellofemoral pain were enrolled. INTERVENTION: The intervention, delivered 2×/week for six weeks, consisted of supervised, high-repetition practice of daily weight-bearing and recreational activities. Activities were selected and progressed based on participants' interest and ability to maintain optimal alignment without increasing pain. MAIN MEASURES: Primary feasibility outcomes were recruitment, retention, adherence, and treatment credibility (Credibility/Expectancy Questionnaire). Secondary outcomes assessing intervention effects were hip and knee kinematics, pain (visual analog scale: current, average in past week, maximum in past week), and function (Patient-Specific Functional Scale). RESULTS: A total of 25 participants were recruited and 23 were retained (92% retention). Self-reported average daily adherence was 79% and participants were able to perform their prescribed home program correctly (reduced hip and knee frontal plane angles) by the second intervention visit. On average, treatment credibility was rated 25 (out of 27) and expectancy was rated 22 (out of 27). Hip and knee kinematics, pain, and function improved following the intervention when compared to the control phase. CONCLUSION: Based on the feasibility outcomes and preliminary intervention effects, this task-specific training intervention warrants further investigation and should be evaluated in a larger, randomized clinical trial.

Hip Abductor Muscle Volume and Strength Differences Between Women With Chronic Hip Joint Pain and Asymptomatic Controls.

Study Design Secondary analysis, cross-sectional study. Background Chronic hip joint pain (CHJP) can lead to limitations in activity participation, but the musculoskeletal factors associated with the condition are relatively unknown. Understanding the factors associated with CHJP may help develop rehabilitation strategies to improve quality of life of individuals with long-term hip pain. Objectives To compare measures of hip abductor muscle volume and hip abductor muscle strength between women with CHJP and asymptomatic controls. Methods Thirty women, 15 with CHJP and 15 matched asymptomatic controls (age range, 18-40 years), participated in this study. Magnetic resonance imaging was used to determine the volume of the primary hip abductor muscles, consisting of the gluteus medius, gluteus minimus, a small portion of the gluteus maximus, and the tensor fascia latae, within a defined region of interest. Break tests were performed using a handheld dynamometer to assess hip abductor strength. During the strength test, the participant was positioned in sidelying with the involved hip in 15° of abduction. Independent-samples t tests were used to compare muscle volume and strength values between those with CHJP and asymptomatic controls. Results Compared to asymptomatic controls, women with CHJP demonstrated significantly increased gluteal muscle volume (228 ± 40 cm3 versus 199 ± 29 cm3, P = .032), but decreased hip abductor strength (74.6 ± 16.8 Nm versus 93.6 ± 20.2 Nm, P = .009). There were no significant differences in tensor fascia lata muscle volume between the 2 groups (P = .640). Conclusion Women with CHJP appear to have larger gluteal muscle volume, but decreased hip abductor strength, compared to asymptomatic controls. J Orthop Sports Phys Ther 2017;47(12):923-930. Epub 9 Oct 2017. doi:10.2519/jospt.2017.7380.

A DYNAMIC VALGUS INDEX THAT COMBINES HIP AND KNEE ANGLES: ASSESSMENT OF UTILITY IN FEMALES WITH PATELLOFEMORAL PAIN.

BACKGROUND: Two=dimensional motion analysis of lower=extremity movement typically focuses on the knee frontal plane projection angle, which considers the position of the femur and the tibia. A measure that includes the pelvis may provide a more comprehensive and accurate indicator of lower=extremity movement. Hypothesis/Purpose: The purpose of the study was to describe the utility of a two=dimensional dynamic valgus index (DVI) in females with patellofemoral pain. The hypothesis was that the DVI would be more reliable and valid than the knee frontal plane projection angle, be greater in females with patellofemoral pain during a single=limb squat than in females without patellofemoral pain, and decrease in females with patellofemoral pain following instruction. Study Design: Controlled Laboratory Study. METHODS: Data were captured while participants performed single limb squats under two conditions: usual and corrected. Two=dimensional hip and knee angles and a DVI that combined the hip and knee angles were calculated. Three=dimensional sagittal, frontal, and transverse plane angles of the hip and knee and a DVI combining the frontal and transverse plane angles were calculated. RESULTS: The two=dimensional DVI demonstrated moderate reliability (ICC=0.74). The correlation between the two=dimensional and three=dimensional DVI's was 0.635 (p<0001). Females with patellofemoral pain demonstrated a greater two=dimensional DVI (31.14 °±13.36 °) than females without patellofemoral pain (18.30 °±14.97 °; p=0.010). Females with patellofemoral pain demonstrated a decreased DVI in the corrected (19.04 °±13.70 °) versus usual (31.14 °±13.36 °) condition (p=0.001). CONCLUSION: The DVI is a reliable and valid measure that may provide a more comprehensive assessment of lower=extremity movement patterns than the knee frontal plane projection angle in individuals with lower=extremity musculoskeletal pain problems. LEVEL OF EVIDENCE: 2b.

Consistency of a lumbar movement pattern across functional activities in people with low back pain.

BACKGROUND: Limitation in function is a primary reason people with low back pain seek medical treatment. Specific lumbar movement patterns, repeated throughout the day, have been proposed to contribute to the development and course of low back pain. Varying the demands of a functional activity test may provide some insight into whether people display consistent lumbar movement patterns during functional activities. Our purpose was to examine the consistency of the lumbar movement pattern during variations of a functional activity test in people with low back pain and back-healthy people. METHODS: 16 back-healthy adults and 32 people with low back pain participated. Low back pain participants were classified based on the level of self-reported functional limitations. Participants performed 5 different conditions of a functional activity test. Lumbar excursion in the early phase of movement was examined. The association between functional limitations and early phase lumbar excursion for each test condition was examined. FINDINGS: People with low back pain and high levels of functional limitation demonstrated a consistent pattern of greater early phase lumbar excursion across test conditions (p<0.05). For each test condition, the amount of early phase lumbar excursion was associated with functional limitation (r=0.28-0.62). INTERPRETATION: Our research provides preliminary evidence that people with low back pain adopt consistent movement patterns during the performance of functional activities. Our findings indicate that the lumbar spine consistently moves more readily into its available range in people with low back pain and high levels of functional limitation. How the lumbar spine moves during a functional activity may contribute to functional limitations.

Movement-Pattern Training to Improve Function in People With Chronic Hip Joint Pain: A Feasibility Randomized Clinical Trial.

Study Design Feasibility randomized clinical trial. Background Rehabilitation may be an appropriate treatment strategy for patients with chronic hip joint pain; however, the evidence related to the effectiveness of rehabilitation is limited. Objectives To assess feasibility of performing a randomized clinical trial to investigate the effectiveness of movement-pattern training (MPT) to improve function in people with chronic hip joint pain. Methods Thirty-five patients with chronic hip joint pain were randomized into a treatment (MPT) group or a control (wait-list) group. The MPT program included 6 one-hour supervised sessions and incorporated (1) task-specific training for basic functional tasks and symptom-provoking tasks, and (2) strengthening of hip musculature. The wait-list group received no treatment. Primary outcomes for feasibility were patient retention and adherence. Secondary outcomes to assess treatment effects were patient-reported function (Hip disability and Osteoarthritis Outcome Score), lower extremity kinematics, and hip muscle strength. Results Retention rates did not differ between the MPT (89%) and wait-list groups (94%, P = 1.0). Sixteen of the 18 patients (89%) in the MPT group attended at least 80% of the treatment sessions. For the home exercise program, 89% of patients reported performing their home program at least once per day. Secondary outcomes support the rationale for conduct of a superiority randomized clinical trial. Conclusion Based on retention and adherence rates, a larger randomized clinical trial appears feasible and warranted to assess treatment effects more precisely. Data from this feasibility study will inform our future clinical trial. Level of Evidence Therapy, level 2b-. J Orthop Sports Phys Ther 2016;46(6):452-461. Epub 26 Apr 2016. doi:10.2519/jospt.2016.6279.

Trunk and lower extremity segment kinematics and their relationship to pain following movement instruction during a single-leg squat in females with dynamic knee valgus and patellofemoral pain.

OBJECTIVES: To understand how instructing females with patellofemoral pain to correct dynamic knee valgus affects pelvis, femur, tibia and trunk segment kinematics. To determine if pain reduction in the corrected condition was associated with improved segment kinematics. DESIGN: Cross-sectional. METHODS: A 3D-motion capture system was used to collect multi-joint kinematics on 20 females with dynamic knee valgus and patellofemoral pain during a single-leg squat in two conditions: usual movement pattern, and corrected dynamic knee valgus. During each condition pain was assessed using a visual analog scale. Pelvis, femur, tibia and trunk kinematics in the frontal and transverse planes were compared between conditions using a paired T-test. Pearson correlation coefficients were generated between visual analog scale score and the kinematic variables in the corrected condition. RESULTS: In the corrected condition subjects had increased lateral flexion of the pelvis toward the weight-bearing limb (p<0.001), decreased femoral adduction (p=0.001) and internal rotation (p=0.01). A trend toward decreased tibial internal rotation (p=0.057) and increased trunk lateral flexion toward the weight-bearing limb (p=0.055) was also found. Lower pain levels were associated with less femoral internal rotation (p=0.04) and greater trunk lateral flexion toward the weight-bearing limb (p=0.055). CONCLUSIONS: Decreased hip adduction after instruction was comprised of motion at both the pelvis and femur. Decreased pain levels were associated with lower extremity segment kinematics moving in the direction opposite to dynamic knee valgus. These results increase our understanding of correction strategies used by females with patellofemoral pain and provide insight for rehabilitation.

Persons with chronic hip joint pain exhibit reduced hip muscle strength.

STUDY DESIGN: Controlled laboratory cross-sectional study. Objectives To assess strength differences of the hip rotator and abductor muscle groups in young adults with chronic hip joint pain (CHJP) and asymptomatic controls. A secondary objective was to determine if strength in the uninvolved hip of those with unilateral CHJP differs from that in asymptomatic controls. BACKGROUND: Little is known about the relationship between hip muscle strength and CHJP in young adults. METHODS: Thirty-five participants with CHJP and 35 matched controls (18 to 40 years of age) participated. Using handheld dynamometry, strength of the hip external rotators and internal rotators was assessed with the hip flexed to 90° and 0°. To assess external rotator and internal rotator strength, the hip was placed at the end range of external rotation and internal rotation, respectively. Strength of the hip abductors was assessed in sidelying, with the hip in 15° of abduction. Break tests were performed to determine maximum muscle force, and the average torque was calculated using the corresponding moment arm. Independent-sample t tests were used to compare strength values between (1) the involved limb in participants with CHJP and the corresponding limb in the matched controls, and (2) the uninvolved limb in participants with unilateral CHJP and the corresponding limb in the matched controls. RESULTS: Compared to controls, participants with CHJP demonstrated weakness of 16% to 28% (P<.01) in all muscle groups tested in the involved hip. The uninvolved hip of 22 subjects with unilateral CHJP demonstrated weakness of 18% and 16% (P<.05) in the external rotators (0°) and abductors, respectively, when compared to the corresponding limb of the matched controls. CONCLUSION: The results of the present study demonstrate that persons with CHJP have weakness in the hip rotator and hip abductor muscles. Weakness also was found in the uninvolved hip of persons with CHJP.

Classification of lower extremity movement patterns based on visual assessment: reliability and correlation with 2-dimensional video analysis.

CONTEXT: Abnormal movement patterns have been implicated in lower extremity injury. Reliable, valid, and easily implemented assessment methods are needed to examine existing musculoskeletal disorders and investigate predictive factors for lower extremity injury. OBJECTIVE: To determine the reliability of experienced and novice testers in making visual assessments of lower extremity movement patterns and to characterize the construct validity of the visual assessments. DESIGN: Cross-sectional study. SETTING: University athletic department and research laboratory. PATIENTS OR OTHER PARTICIPANTS: Convenience sample of 30 undergraduate and graduate students who regularly participate in athletics (age = 19.3 ± 4.5 years). Testers were 2 experienced physical therapists and 1 novice postdoctoral fellow (nonclinician). MAIN OUTCOME MEASURE(S): We took videos of 30 athletes performing the single-legged squat. Three testers observed the videos on 2 occasions and classified the lower extremity movement as dynamic valgus, no change, or dynamic varus. The classification was based on the estimated change in frontal-plane projection angle (FPPA) of the knee from single-legged stance to maximum single-legged squat depth. The actual FPPA change was measured quantitatively. We used percentage agreement and weighted κ to examine tester reliability and to determine construct validity of the visual assessment. RESULTS: The κ values for intratester and intertester reliability ranged from 0.75 to 0.90, indicating substantial to excellent reliability. Percentage agreement between the visual assessment and the quantitative FPPA change category was 90%, with a κ value of 0.85. CONCLUSIONS: Visual assessments were made reliably by experienced and novice testers. Additionally, movement-pattern categories based on visual assessments were in excellent agreement with objective methods to measure FPPA change. Therefore, visual assessments can be used in the clinic to assess movement patterns associated with musculoskeletal disorders and in large epidemiologic studies to assess the association between lower extremity movement patterns and musculoskeletal injury.

Tibiofemoral and patellofemoral mechanics are altered at small knee flexion angles in people with patellofemoral pain.

OBJECTIVES: To test the hypothesis that, at 0° and 20° of knee flexion, patellofemoral contact area would be lower, while tibiofemoral rotation and patellofemoral malalignment would be higher in participants with patellofemoral pain (PFP) compared to pain-free participants. We hypothesized that no differences would be detected at 40° due to increasing patellar stability. DESIGN: Cross-sectional, descriptive study. METHODS: Twenty-seven people with PFP and 29 pain-free people participated. Participants underwent magnetic resonance imaging at 0°, 20°, and 40° knee flexion with the limb in a simulated weight-bearing position. Patellofemoral contact area, tibiofemoral rotation angle, patellofemoral alignment (bisect offset index and patellar tilt angle) were quantified and compared between groups at each angle using Student's t-tests. An a-posteriori comparison was made between the pain-free group and a subgroup of 15 participants with patellofemoral pain who demonstrated a faulty lower limb movement pattern ("medial collapse"). RESULTS: In the patellofemoral pain group, contact area was lower at 0° (203.8±45.5 mm² vs. 224.1±46.6 mm², p=0.05) and 20° (276.8±56.2 mm² vs. 316.7±82.8 mm², p=0.02), bisect offset index (BOS) and patellar tilt angle (PTA) were higher at 0° (bisect offset index: 0.69±0.13 vs. 0.64±0.09, p=0.04; patellar tilt angle: 12.5±7.6° vs. 9.2±5.8°, p=0.04). In the patellofemoral pain subgroup, tibiofemoral rotation was higher at 0° compared to pain-free participants (6.4±5.9° vs. 4.0±4.6°, p=0.07). CONCLUSIONS: While contact area and patellofemoral alignment were altered in people with patellofemoral pain, tibiofemoral rotation was altered in a subgroup of people who demonstrated medial collapse. Subgroup classification may help identify mechanisms of pain and assist in developing targeted interventions.

The effects of movement pattern modification on lower extremity kinematics and pain in women with patellofemoral pain.

STUDY DESIGN: Controlled laboratory study. OBJECTIVES: To compare hip and knee kinematics and pain during a single-limb squat between 3 movement conditions (usual, exaggerated dynamic knee valgus, corrected dynamic knee valgus) in women with patellofemoral pain. BACKGROUND: Altered kinematics (increased hip adduction, hip medial rotation, knee abduction, and knee lateral rotation, collectively termed dynamic knee valgus) have been proposed to contribute to patellofemoral pain; however, cross-sectional study designs prevent interpreting a causal link between kinematics and pain. METHODS: The study sample included 20 women with patellofemoral pain, who demonstrated observable dynamic knee valgus. Participants performed single-limb squats under usual, exaggerated, and corrected movement conditions. Pain during each condition was assessed using a 0-to-100-mm visual analog scale. Hip and knee frontal and transverse plane angles at peak knee flexion and pain levels were compared using repeated-measures 1-way analyses of variance. Pearson correlation coefficients were used to determine within-condition associations between kinematic variables and pain. RESULTS: In the exaggerated compared to the usual condition, increases were detected in hip medial rotation (mean ± SD difference, 5.8° ± 3.2°; P<.001), knee lateral rotation (5.5° ± 4.9°, P<.001), and pain (8.5 ± 10.8 mm, P = .007). In the corrected compared to the usual condition, decreases were detected in hip adduction (mean ± SD difference, 3.5° ± 3.7°; P = .001) and knee lateral rotation (1.6° ± 2.8°, P = .06); however, average pain was not decreased (1.2 ± 14.8 mm, P = 1.0). Pain was correlated with knee lateral rotation in the usual (r = -0.47, P = .04) and exaggerated (r = -0.49, P = .03) conditions. In the corrected condition, pain was correlated with hip medial rotation (r = 0.44, P = .05) and knee adduction (r = 0.52, P = .02). CONCLUSION: Avoiding dynamic knee valgus may be an important component of rehabilitation programs in women with patellofemoral pain, as this movement pattern is associated with increased pain.