Article

Bending down and kneeling are fundamental tasks of daily living, yet
nearly a quarter of older adults report having difficulty performing or being
unable to perform these movements. Older adults with stooping, crouching, or
kneeling (SCK) difficulty have demonstrated an increased fall risk. Strength
(force-generating capacity) measures may be useful for determining both SCK
difficulty and fall risk. OBJECTIVE: The purposes of this study were: (1) to
examine muscle strength differences in older adults with and without SCK
difficulty and (2) to examine the relative contributions of trunk and leg muscle
strength to SCK difficulty. DESIGN: This was a cross-sectional observational
study. METHODS: Community-dwelling older adults (age [X+/-SD]=75.5+/-6.0 years)
with SCK difficulty (n=27) or without SCK difficulty (n=21) were tested for leg
and trunk strength and functional mobility. Isometric strength at the trunk, hip,
knee, and ankle also was normalized by body weight and height. RESULTS: Compared
with older adults with no SCK difficulty, those with SCK difficulty had
significant decreases in normalized trunk extensor, knee extensor, and ankle
dorsiflexor and plantar-flexor strength. In 2 separate multivariate analyses, raw
ankle plantar-flexor strength (odds ratio [OR]=0.97, 95% confidence interval
[CI]=0.95-0.99) and normalized knee extensor strength (OR=0.61, 95% CI=0.44-0.82)
were significantly associated with SCK difficulty. Stooping, crouching, and
kneeling difficulty also correlated with measures of functional balance and
falls. LIMITATIONS: Although muscle groups that were key to rising from SCK were
examined, there are other muscle groups that may contribute to safe SCK
performance. CONCLUSIONS: Decreased muscle strength, particularly when normalized
for body size, predicts SCK difficulty. These data emphasize the importance of
strength measurement at multiple levels in predicting self-reported functional
impairment.

Langue : ANGLAIS