Threshold of lower body muscular strength necessary to perform ADL independently in community-dwelling older adults.

OBJECTIVE

To determine the thresholds of lower extremity muscle strength below which performing activities of daily living (ADL) is impaired in older adults.

DESIGN

Cross-sectional.

SETTING

Community.

SUBJECTS

Forty-nine older adults (81-89 years) were divided into an independent group (n = 25) who needed no assistance and a dependent group (n = 24) who needed assistance to perform ADL.

INTERVENTIONS

Not applicable.

MAIN MEASURES

Functional independence measures to determine level of disability and muscular strength of hip flexors, hip extensors, knee flexors, knee extensors and ankle dorsiflexors assessed by a hand-held dynamometer (HHD). Muscle groups were tested separately for each leg and values were averaged for the two legs. A ratio of maximal muscular strength to body weight was calculated by dividing the muscular strength (N) by body weight (kg).

RESULTS

Muscular strength thresholds to perform ADL independently were 2.3 N/kg for hip flexors, 1.7 N/kg for hip extensors, 0.7 N/kg for knee flexors, 2.8 N/kg for knee extensors and 2.8 N/kg for ankle dorsiflexors.

CONCLUSION

The thresholds of lower extremity muscle strength below which assistance is required to perform ADL in community-dwelling older adults were identified. Furthermore, results indicate that the muscular strength of hip extensors is more important in performing ADL than other muscles of the lower extremities.