The purpose of this study was to compare unilateral squat strength of the dominant and non-dominant leg in young adult men and women. Seventeen apparently healthy men (mean mass 90.5 ± 20.9 kg and age 21.7 ± 1.8 yrs) and 25 women (mean mass 62.2 ± 14.5 kg and age 21.9 ± 1.3 yrs) completed the study. To determine unilateral strength, the subjects completed a one repetition maximum (1RM) modified unilateral squat (MUS) on the dominant and non-dominant leg. The subjects completed the squat to a depth that attained a 90° angle at the knee. This exercise was executed by placing the top of the metatarsophalangeal area of the foot of the uninvolved leg on a support bar behind the subject to isolate the use of the lead leg. Paired samples t-test revealed no significant difference between the men's 1RM mean strength on the dominant (107.0 ± 21.4 kg) and non-dominant (106.0 ± 21.4 kg) leg with a mean side-to-side difference (comparing the stronger to the weaker leg) of 2.8 %. Leg strength symmetry was also found between the women's 1RM mean strength on the dominant (45.3 ± 12.5 kg) and non-dominant (45.0 ± 12.4 kg) leg with a mean side-to-side difference of 5.0 %. The data indicate that unilateral squat strength, measured in a weight bearing stance, is similar in the dominant and non-dominant leg in apparently healthy young adult men and women. Key PointsMUS strength was similar between the dominant and non-dominant leg in young adult men and women.Mean side-to-side differences (comparing the stronger to the weaker leg) resulted from higher dominant and non-dominant scores for the men and womenThe range of side-to-side differences warrants the practice of weight bearing strength assessment to identify those at risk for injury.
Keywords: Closed Chain; limb symmetry; single-leg strength; unilateral assessment.