Association Between Isokinetic Lower Extremity Muscle Strength and Bone Mineral Density in Elderly Women With and Without Osteoporosis: A Case-Control Study

Abstract

Objective

The purpose of this study was to explore the relationship between isokinetic hip and knee muscle strength and bone mineral density (BMD) in elderly women with osteoporosis (OP).

Methods

The study included 66 elderly women: 33 with OP (case group A) and 33 healthy controls (control group B). BMD at the femoral head was assessed using Dual Energy X-ray Absorptiometry (DEXA). Isokinetic muscle strength of the hip (flexors, extensors, abductors, adductors) and knee (flexors, extensors) was measured using the Biodex System 3 Isokinetic Dynamometer at 60°/sec in concentric mode, with 5 repetitions.

Results

The analysis revealed significantly lower strength in all hip muscles in women with OP compared to controls (p < .05). Meanwhile, no significant differences were observed in knee muscle strength between the 2 groups. The findings suggest that reductions in BMD are more closely associated with decreased hip muscle strength than with knee muscle strength.

Conclusion

Diminished isokinetic strength of hip muscles is more strongly linked to BMD reduction in elderly women with OP. Low BMD may serve as a risk factor for lower extremity muscle weakness, emphasizing the need to focus on hip muscle strength in this population.