Muscle Weakness In Older Adults

It is well documented that older adults experience a decrease in muscle strength, as well an increase in falls with age. The capacity of a muscle to produce force is an important aspect in sustaining balance and thus reducing falls. Therefore, it is hypothesized that muscle weakness is a potentially modifiable risk factor in falls in older adults. Though muscle weakness is a risk factor for falls, it is important to identify if strength training prevents falls and if so what muscle groups in particular should be trained.

A systematic review Muscle weakness and falls in older adults, by Moreland, evaluated and summarized the evidence behind muscle weakness as a risk factor in falls for older adults (5). 127 articles met the criteria for the

(N=39) The first exercise program included resistance exercises, balance and gait and the second exercise program included seated hip ROM. In comparing pre- and post- test results, there was a more significant increase in all variables of the resistance training group, thus concluding that strength training can reduce muscle weakness and falls in older adults. (2) Liu’s study found that ankle dorsiflexor strength is the most important differentiation between fallers and non-fallers (2). Additionally, dorsiflexor strengthening has been connected to both increased cadence and increased balance. This is associated with increased risk of tripping (falling) if one is unable to clear the foot during the gait cycle. Improvement in the Ankle Dorsiflexor Scale (ADFS), has shown to have a good correlation to one’s balance and stability during activities of daily living. Another study by Sieri, on fall risk assessment in the elderly in nursing homes, revealed that fallers had greater deficits in LE strength and power as well as decreased walking speed compared to non-fallers (1). However, Sieri’s study found that the greatest deficit of strength in the males was ankle plantarflexion and knee extensor strength and in the females was knee extensor strength. In a study by Emilio, on the association of flexibility, balance and lumbar strength with balance ability, the muscle in focus was lumbar extensors. They found that the trained subjects significantly improved lumbar strength (dynamometry) as well as dynamic balance (BBS) and lower body flexibility compared to the non-trained individuals. (4) Therefore showing the association between flexibility, balance and strength and balance ability and risk of falls.