Single‐Leg Squat Performance is Impaired 1 to 2 Years After Hip Arthroscopy

Abstract

Single leg squat performance is impaired one to two years after hip arthroscopy ABSTRACT 1 2 Objective: 1. Evaluate single leg squat performance 1-2 years after arthroscopy for intra-3 articular hip pathology, compared to controls and the non-operative limb. 2. Investigate 4 whether single leg squat performance on the operated limb was associated with hip muscle 5 strength. 6Design: Cross-sectional study 7Setting: Private physiotherapy clinic and university laboratory. 8Participants: Thirty-four participants (17 females, 36.7±12.6 years) 1-2 years following hip 9 arthroscopy, and 34 sex-matched controls (17 females, 33.1±11.9 years) 10 Methods: Participants performed single leg squats using a standardized testing procedure. 11Squat performance was captured using video. Video footage was uploaded and reformatted 12 for analyses. Hip muscle strength was measured with hand-held dynamometry using reliable 13 methods. 14 Outcome measures: Frontal plane pelvic obliquity, hip adduction and knee valgus were 15 measured. Repeated measures analysis of variance evaluated between-group differences, with 16 limb as a within-subjects factor (operated versus non-operated) and sex as a between-subjects 17 factor (p<.05). 18 Results:The hip arthroscopy group demonstrated significantly greater apparent hip 19 adduction (mean difference 2.7°, 95% CI 0.7° to 4.8°) and apparent knee valgus (4.0°, 95% 20 CI 1.0° to 7.1°) at peak squat depth, compared to controls. The operated limb also 21 demonstrated significantly greater pelvic obliquity during single leg stance compared to the 22 M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 2 non-operated limb (1.2°, 95% CI 0.1° to 2.3°). Females had significantly greater apparent hip 23 adduction (standing 1.6°, 95% CI 0.5° to 2.6°; peak squat depth 95% CI 2.4°, 0.3° to 4.4°) 24 and apparent knee valgus (standing 3.3°, 95% CI 1.8° to 4.7°; peak squat depth 3.1°, 95% CI 25 0° to 6.1°). Significant positive correlations were found between frontal plane angles and hip 26 flexor and extensor peak torque (p>.05). 76The primary aim of this study was to determine whether people who have undergone hip 77 arthroscopy for intra-articular hip pathology 1-2 years previously demonstrate deficits in 78 single leg squat performance: i) compared to control participants; and ii) compared to their 79 non-operated limb. It was hypothesized that participants would exhibit greater pelvic 80 obliquity, frontal plane hip angle (FPHA) and frontal plane knee angle (FPKA), at peak squat 81 depth on their operated limb, compared to controls and compared to the non-operated limb. 82The secondary aim was to investigate whether single leg squat performance on the operated 83 Consecutive patients aged 18 to 60 at the time of surgery were invited to participate one to 97 two years post-operatively. Volunteers were deemed ineligible to participate if they had 98 subsequently undergone total hip arthroplasty, had concurrent lower limb injuries, were 99 unable to walk without assistance, or were unable to understand w...

Physical impairments in symptomatic femoroacetabular impingement: a systematic review of the evidence

“…A lack of consistency in the control groups makes it difficult to have confidence in the validity of between-group differences reported. These findings are similar to those in a recent study by Charlton et al 59 that reported patients' posthip arthroscopy having increased frontal plane hip adduction and knee valgus compared with controls. The authors suggested that this may perpetuate impingement load in the hip during single leg functional tasks and called for targeted rehabilitation programmes to improve lower limb control during these tasks 59.…”

“…These findings are similar to those in a recent study by Charlton et al 59 that reported patients' posthip arthroscopy having increased frontal plane hip adduction and knee valgus compared with controls. The authors suggested that this may perpetuate impingement load in the hip during single leg functional tasks and called for targeted rehabilitation programmes to improve lower limb control during these tasks 59. Biomechanically, some studies suggest that symptomatic FAI affects walking by reducing speed60 and limiting ROM in the sagittal and frontal planes46 60 61 as well as reducing peak hip extension, abduction,46 61 adduction and internal rotation during the stance phase of gait 60.…”

Physical impairments in symptomatic femoroacetabular impingement: A Systematic review of the evidence

“…The authors suggested that this may perpetuate impingement load in the hip during single leg functional tasks and called for targeted rehabilitation programmes to improve lower limb control during these tasks. 59 Biomechanically, some studies suggest that symptomatic FAI affects walking by reducing speed 60 and limiting ROM in the sagittal and frontal planes 46 60 61 as well as reducing peak hip extension, abduction, 46 61 adduction and internal rotation during the stance phase of gait. 60 These findings contradict the conclusions of this review where no significant difference was noted in ROM between individuals with symptomatic FAI and normal controls.…”

The HAPI ‘Hip Arthroscopy Pre-habilitation Intervention’ study: does pre-habilitation affect outcomes in patients undergoing hip arthroscopy for femoro-acetabular impingement?

“…Since completion of this study, further evidence has been published reporting specific muscle weakness in subjects with labral pathology [27], in FAI [31] and post-hip arthroscopy [32]. Recommendations as a result of these studies have been made to target single leg squats [32] and hip flexor strength in rehabilitation [2]. Our study demonstrated statistical significance regarding the positive benefits of pre-operative exercise in these two muscle groups, with the intervention group performing better in strength (hip flexion P  = 0.02 and knee extension/quadriceps P  = 0.05).…”