Field-Based Simplified Approach of Evaluating Knee Extensor Muscle Strength and Size in University Freshmen Women.

CONTEXT: Periodic assessment of knee extensor muscle strength and size is important for all ages to evaluate the functional status of individuals and to identify and treat those at risk for mobility problems and frailty; however, it is not fully understood whether these field-based simplified approaches correspond to evaluation in knee extensor muscle strength or size.

OBJECTIVE: To examine the relationship between field-based simplified evaluation approaches and knee extensor muscle strength or size in young women.

DESIGN: Experimental.

SETTING: University research laboratory.

SUBJECTS: 62 university freshmen women volunteered to participate in this study.

MAIN OUTCOME MEASURES: Knee extensor muscle thickness was measured at the anterior half of thigh length; muscle strength was measured when subjects performed knee extension. Field-based simplified approaches [sit-to-stand, standing long jump, handgrip and upper-leg 50% (thigh) girth] were also measured.

RESULTS: Maximal strength was correlated with thigh girth, handgrip and standing long jump, but not with the sit-to-stand test. Muscle thickness was correlated with thigh girth and handgrip, but not with standing long jump or the sit-to-stand test. A stepwise multiple-regression analysis was calculated using the predictor thigh girth and standing long jump to predict knee extensor maximal strength (R2 = 0.295). To predict knee extensor muscle thickness, the predictor thigh girth was calculated (R2 = 0.381).

CONCLUSIONS: Knee extensor muscle strength and size could be evaluated by the field-based simplified approaches, in particular by the thigh girth measurement, which may be a major determinant to maintain activities of daily living for healthy young women. However, the 4 field-based simplified approaches appear to be still not of high impact.