Single-Leg Squat Test in the Clinical Setting Does Not Discriminate Patients With Femoroacetabular Impingement Syndrome From Asymptomatic Individuals.

CONTEXT: Laboratorial 3-dimensional kinematic analyses have shown changes in the single-leg squat's (SLS) pattern of patients with femoroacetabular impingement syndrome (FAIS). However, it is unknown whether clinicians are able to detect these changes using 2-dimensional kinematics. OBJECTIVE: To compare the frontal plane 2-dimensional kinematics of patients with FAIS and asymptomatic individuals in the SLS test performed in a clinical setting. DESIGN: Case-control study. SETTING: Physical therapy clinic. PARTICIPANTS: Twenty men with bilateral FAIS and 20 asymptomatic men. MAIN OUTCOME MEASURES: Two-dimensional kinematic analysis was collected in the frontal plane during the execution of the SLS test. The outcomes were squat depth, pelvic drop (pelvis angle relative to the horizontal plane), hip adduction (femur angle relative to the pelvis), and knee valgus (femur angle relative to the tibia). RESULTS: Most and least painful limbs of patients with FAIS had squat depth (9.8% [2.9%] and 9.5% [3.1%] of height), pelvic drop (4.2° [3.9°] and 3.7° [4.2°]), hip adduction (74.9° [5.8°] and 75.9° [5.7°]), and knee valgus (4.0° [11.0°] and 5.0° [9.9°]) similar to asymptomatic individuals (9.0% [2.3%], 4.8° [2.6°], 73.7° [4.9°], and -1.7° [8.5°]; P > .05 for all). CONCLUSION: The frontal plane 2-dimensional kinematic analysis of the SLS test in the clinical setting is not able to distinguish patients with FAIS from asymptomatic individuals.

Hip muscle weakness and reduced joint range of motion in patients with femoroacetabular impingement syndrome: a case-control study.

BACKGROUND: Femoroacetabular impingement (FAI) syndrome is a hip joint motion-related clinical disorder characterized by abnormal contact between the hip joint structures. Abnormal hip morphology and joint pain may impair the hip joint range of motion (ROM) and muscle function. However, FAI effects on hip joint ROM and muscle strength remain controversial. OBJECTIVES: The purpose of this study was to compare hip joint ROM and muscle strength between FAI syndrome patients and healthy controls. METHODS: Twenty FAI syndrome male patients and 20 healthy male controls (CG) matched for age (FAI=28±6 years; CG=27±5 years), body mass (FAI=81±12kg; CG=80±13kg) and height (FAI=177±6cm; CG=178±6cm), participated in the study. Hip joint ROM for flexion, internal rotation and external rotation were assessed through goniometry. Maximal isometric strength for hip flexion, extension, abduction and adduction were evaluated through hand-held dynamometry. RESULTS: Hip joint ROM was significantly lower in FAI syndrome patients compared with CG for passive flexion (-4%; effect size - ES=0.65), active internal rotation (-42%; ES=1.60), active external rotation (-28%; ES=1.46) and passive external rotation (-23%; ES=1.63). FAI patients' hip extensors (-34%; ES=1.46), hip adductors (-33%; ES=1.32), and hip flexors (-25%; ES=1.17) were weaker compared to the CG subjects. CONCLUSIONS: FAI syndrome patients presented both hip muscle weakness and reduced joint ROM compared to match CG.