Are visual assessments of the single-leg squat valid to be used in clinical practice? A systematic review of measurement properties based on the COSMIN guideline.

OBJECTIVE: Evaluate the discriminative and convergent validity of visual scales for the assessment of movement quality in the single-leg squat. METHODS: Searches performed in CINAHL, Cochrane, Embase, PubMed, SPORTDiscus and Web of Science databases. Studies evaluating discriminative and convergent validity of movement quality visual assessments in single-leg squats were included. The COSMIN risk of bias checklist was used to assess the risk of bias, and certainty of evidence was assessed by the GRADE modified version. RESULTS: Ten studies evaluating three different methods of visual assessment of the single-leg squat (Crossley scale; Whatman score and Medial knee displacement) were included. Very low certainty evidence suggests that the Crossley scale had sufficient discriminative validity for patient-centred outcomes. Very low to moderate certainty evidence suggests that the three visual methods of assessment of the single-leg squat had insufficient discriminative validity for surrogate outcomes and groups. None of the three methods had the convergent validity assessed. CONCLUSION: The Crossley scale exhibited sufficient discriminative validity for patient-centred outcomes, although the evidence supporting this conclusion is of very low certainty. Visual scales for the assessment of the single-leg squat movement quality should be used with caution in clinical practice as most methods had insufficient discriminative validity and no reports of convergent validity.

Differences in hip torque ratios between individuals with femoroacetabular impingement syndrome and asymptomatic individuals: A cross-sectional study.

BACKGROUND: Hip torque ratios are considered a useful measure for patients with hip pain. However, evidence regarding this measure for patients with femoroacetabular impingement syndrome is scarce. The primary aim of this study was to compare hip external-internal rotation and abduction-adduction torque ratios between patients with femoroacetabular impingement syndrome and asymptomatic individuals. The secondary aim was to compare hip torque ratios between the asymptomatic group and femoroacetabular impingement syndrome patients grouped according to the severity of symptoms and functional limitations. METHODS: Hip abduction-adduction and external-internal rotation torque ratios of 134 individuals with femoroacetabular impingement syndrome and 134 asymptomatic matched controls was assessed through isokinetic testing. Severity of symptoms and functional limitations was assessed through the iHOT-33. Mann Whitney U and Kruskall-Wallis tests were used to compare hip torque ratios between asymptomatic individuals and patients with femoroacetabular impingement syndrome and to patients with femoroacetabular impingement syndrome with different severities of symptoms and functional limitations. FINDINGS: No differences were identified in hip abduction-adduction (U = 7659.5, p = 0.192) and external-internal rotation (U = 8787.5, p = 0.764) torque ratios between patients with femoroacetabular impingement syndrome and asymptomatic individuals. Hip abduction-adduction torque ratio was higher (p = 0.0127) in patients with a severe state (median = 1.80, IQR = 0.61) when compared to asymptomatic individuals (median = 1.52, IQR = 0.45) (moderate effect size, r = 0.45). INTERPRETATION: Patients with severe symptoms and functional limitations related to FAI syndrome presented greater hip abduction-adduction torque ratio than asymptomatic individuals, suggesting a decreased adduction torque capacity relative to abduction torque in this subgroup of femoroacetabular impingement.

Knee and hip dynamic muscle strength in individuals with femoroacetabular impingement syndrome scheduled for hip arthroscopy: A case-control study.

Background The primary aim of this study was to compare knee and hip dynamic muscle strength of individuals with femoroacetabular impingement (FAI) syndrome scheduled for hip arthroscopy with healthy controls. Our secondary aim was to compare hip and knee muscle strength between male and female patients with FAI syndrome. Methods One hundred and thirty-four individuals with femoroacetabular impingement syndrome scheduled for hip arthroscopy and 134 healthy controls matched for sex and age (within 5 years range) underwent an isokinetic assessment of knee extension and flexion and hip abduction, adduction, external rotation and internal rotation dynamic muscle strength. Two MANOVAs were conducted to compare isokinetic peak torque and total work between groups and sexes. Findings Individuals with femoroacetabular impingement syndrome demonstrated lower values of all variables representing knee and hip isokinetic peak torque and total work measures when compared to healthy controls, with differences ranging from 0.09 Nm/kg (95%CI: 0.06-0.12 Nm/kg) to 0.64 Nm/kg (95%CI: 0.49-0.79 Nm/kg). Female participants from both FAI syndrome and control group showed less knee and hip muscle strength compared to male participants. There was no significant interaction between group and sex regarding knee or hip isokinetic peak torque and total work (p > 0.05). Interpretation Individuals with femoroacetabular impingement syndrome scheduled for hip arthroscopy present impairments in knee or hip dynamic muscle strength when compared to controls. Female participants present less knee and hip muscular strength compared to male participants, these between-sex differences are similar for both FAI syndrome and control group participants.

Association between severity of hip chondrolabral injuries, dynamic hip muscle strength and quality of life: A cross-sectional study in patients with femoroacetabular impingement syndrome scheduled for hip arthroscopy.

BACKGROUND: We assessed the association between: the severity of hip chondral or labral pathology with dynamic hip muscle strength or quality of life in patients with femoroacetabular impingement syndrome scheduled for hip arthroscopy. We also assessed the association between dynamic hip muscle strength with quality of life. METHODS: Eighty-three participants with femoroacetabular impingement syndrome scheduled for hip arthroscopy were included. We measured dynamic hip abduction and adduction muscle strength with an isokinetic dynamometer (Nm/kg), and quality of life with the iHoT-33 questionnaire. The severity of hip chondrolabral pathologies was scored using the modified Beck classification. Linear regression analyses were conducted to assess the association between severity of hip chondral or labral pathology with dynamic hip muscle strength and quality of life. FINDINGS: The regression analyses showed no association between the (i) severity of hip chondral (adjusted r2: 0.14) or labral (adjusted r2: 0.08) pathology and quality of life (P > 0.05), (ii) between the severity of hip chondral or labral pathology and dynamic hip abduction and adduction muscle strength (P > 0.05). Significant correlation was observed for quality of life and hip abduction (adjusted r2:0.29; P < 0.001) or adduction (adjusted r2: 0.32; P < 0.001) muscle strength. INTERPRETATION: The severity of hip chondral or labral pathologies were not associated with quality of life or dynamic hip muscle strength in participants with femoroacetabular impingement syndrome. Greater dynamic hip abduction and adduction muscle strength were associated with better quality of life in participants with femoroacetabular impingement syndrome scheduled for hip arthroscopy.