Lower-extremity muscle forces measured by a hand-held dynamometer and the risk of falls among day-care users in Japan: using multinomial logistic regression analysis.
OBJECTIVE
To assess the relationship between the lower extremity muscle forces and risk of falls among the elderly who were using day-care services in the long-term care insurance system.


METHODS
The study population comprised 96 women aged 69 - 91 years. At baseline, we assessed ADL, functional capacity, isometric muscle forces of knee extension and ankle dorsiflexion obtained with a hand-held dynamometer. After 1 year, we asked subjects about falls during the follow up period.


RESULTS
In univariate analysis, only the knee extensor strength (p = 0.003) and ankle dorsiflexor strength (p = 0.02) differed significantly according to the fall status. After adjustment for age using multinomial logistic regression analysis, the weak quadriceps group was 7.50 times more likely than the strong group to fall once (p = 0.02), and 5.00 times more likely to fall twice or more (p = 0.02). The weakest ankle dorsiflexor group was 5.09 times more likely than the strongest group to fall twice or more (p = 0.05).


CONCLUSIONS
Our results indicated that the forces of knee extensor and ankle dorsiflexor were strongly associated with falls among day-care users. Physiotherapy should focus on the lower-extremity muscle strength to prevent falls and deterioration of physical ability among elderly persons who are partially dependent and need support.
Department of Preventive Medicine and Health Promotion, Nagasaki University School of Medicine, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan. koh-t@ngs1.cncm.ne.jp
Kotaro
K
Takazawa
Kokichi
K
Arisawa
Sumihisa
S
Honda
Yoshisada
Y
Shibata
Hiroshi
H
Saito
D000058:Accidental Falls / Q000517:prevention & control* / Q000706:statistics & numerical data; D000368:Aged; D000369:Aged, 80 and over; D000843:Ankle Joint / Q000502:physiology; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D007537:Isometric Contraction; D007564:Japan; D007719:Knee Joint / Q000502:physiology; D016015:Logistic Models; D035002:Lower Extremity; D018908:Muscle Weakness / Q000175:diagnosis*; D012306:Risk