Comparative Effects of 4 Single-Leg Squat Exercises in Subjects With Gluteus Medius Weakness

J Sport Rehabil. 2018 Nov 1;27(6):513-519. doi: 10.1123/jsr.2016-0193. Epub 2018 Jun 22.

Abstract

Context: Of the weight-bearing exercises, single-leg squats (SLSs) represent one of the most commonly used hip-strengthening exercises that require more gluteus medius (GMED) activity. To date, no studies have investigated how the 4 SLS exercises affect muscle imbalance of GMED, tensor fasciae latae (TFL), and adductor longus (AL), and kinematics of hip.

Objective: To investigate the hip muscle activities, onset time, and kinematics during 4 different SLS exercises (unilateral squat, unilateral wall-squat [UWS], lateral step-down, and front step-down) in subjects with GMED weakness.

Design: Repeated-measures experimental design.

Setting: Research laboratory.

Participants: Twenty-two subjects (11 males and 11 females) participated in this study and were compared using 1-way repeated-measures analysis of variance.

Main outcome measures: Surface electromyography was used to measure the muscle activities and onset time of the GMED, TFL, and AL, and 3-dimensional motion tracking system was used to measure the hip adduction and internal/external rotation angles during SLS exercises. One-way repeated-measures analysis of variance was used at a significance level of P < .05.

Results: The UWS produced higher GMED/TFL activity ratio and lower GMED/TFL onset time ratio than in the other 3 exercises (P < .05). No difference in GMED/AL activity ratio and GMED/AL onset time ratio was observed. The hip adduction angle was greater in UWS than in the other 3 exercises (P < .05). As for the hip internal/external rotation, lateral step-down exhibited higher hip internal rotation angle than front step-down (P < .05).

Conclusion: The UWS may be recommended as an effective exercise for the subjects with GMED weakness, but they should take care to avoid excessive hip adduction during the exercise.

Keywords: adductor longus; muscle imbalance; onset time; tensor fasciae latae.

Publication types

  • Comparative Study

MeSH terms

  • Biomechanical Phenomena
  • Buttocks
  • Electromyography
  • Exercise Therapy*
  • Female
  • Humans
  • Male
  • Muscle, Skeletal / physiopathology*
  • Rotation
  • Thigh
  • Weight-Bearing*
  • Young Adult