Performance on the Single-Leg Squat Task Indicates Hip Abductor Muscle Function

Abstract

Targeted treatments, although considered ideal, rely on the capacity to identify subgroups of people with chronic anterior knee pain who might respond optimally to a given treatment component. Clinical assessment of performance on the single-leg squat task is a reliable tool that may be used to identify people with hip muscle dysfunction.

Description of a Weight-Bearing Method to Assess Hip Abductor and External Rotator Muscle Performance

“…3,8,10,13,15,20,27,28 The hip muscles, specifically the abductors and external rotators, not only provide local structural stability to the hip joint but are also important in maintaining proper segmental alignment of the lower extremity during weight-bearing tasks. 5,21,26 Inability of the hip abductors and external rotators to produce adequate torque during weight-bearing activities can lead to pelvic drop, excessive hip adduction, excessive hip internal rotation, and an increase in the knee valgus angle. 10,16,19,20,25,27 In addition, a number of studies have shown that hip abductor muscle performance is significantly correlated with postural stability and locomotion function in older adults 2 and persons who have undergone arthroplastic surgery of the lower extremity joints.…”

A preliminary reliability study of a qualitative scoring system of limb alignment during single leg squat

“…All participants were allowed a maximum of three practice attempts. In accordance with previous investigations [21,24,32], squat depth was not standardised in keeping with an approach that most closely resembles clinical practice.…”

“…A qualitative scoring system was devised by one of authors (LH) based on the previously reported scoring systems of Crossley et al, [24] and Whatman et al, [27]. It involved dichotomous scoring of the movement strategy occurring in individual body regions (arm, trunk, pelvis, thigh, knee, foot).…”

“…These studies investigated the reliability of visual assessment of SLS or single limb mini squat tests or the small knee bend (SKB) which have disclosed inconsistent results (inter-observer =slight to excellent; intra-observer=fair to excellent) [22]. Ageberg et al, [10]; Weir et al, [23]; Crossley et al, [24]; Pousen et al, [25]; Örtqvist et al, [26]; Weeks et al, [21] [20,27] reported the use of a variety of protocols that included differences in the amount of knee flexion, foot position, arm position, head position and movement tempo. Some studies used a small box to squat from [24] or allowed finger tip balance [10].…”

“…Ageberg et al, [10]; Weir et al, [23]; Crossley et al, [24]; Pousen et al, [25]; Örtqvist et al, [26]; Weeks et al, [21] [20,27] reported the use of a variety of protocols that included differences in the amount of knee flexion, foot position, arm position, head position and movement tempo. Some studies used a small box to squat from [24] or allowed finger tip balance [10]. The different protocols may present different challenges to neuromuscular control and result in different movement patterns that influence reliability.…”