Exercise programs that are individualized and moderately challenge balance to address falls risk factors are recommended for preventing falls in community-dwelling older adults. Little is known regarding the biomechanical and postural control demands in exercises commonly performed in falls prevention programs. Twenty-two non-sedentary, healthy older adults (11 men, 11 women, mean age 69 5 years) performed 5 standing exercises (hip abduction (HA), side step (SS), squat (SQ), forward lunge (FL), and side lunge (SL)) commonly performed in efficacious falls prevention programs. A biomechanical analysis of the dominant limb was performed using motion-capture and kinetic data to calculate peak joint angles and peak net joint moments, peak power and total work at the ankle, knee and hip in multiple planes. Center of pressure (CoP) measures of mean time-to-boundary (TTB), mean velocity, path length, and 95% confidence ellipse area were also analyzed during performance of the SS and HA exercises.
Significant differences and some degree of ranking in characteristics of biomechanical demand was found along with significant differences in characteristics of postural control demand between the SS and HA. Greater joint angles at the ankle, knee and hip were generally found during the SQ exercise. The FL demonstrated characteristics of greater hip extension demand while the SL demonstrated greater knee extension moment. The SS and HA exercises generally demonstrated greater or similar demand to other exercises in sagittal plane ankle and frontal plane hip kinetics. Differences in characteristics of postural control were found between the HA and SS exercises. Study findings suggest the SS exercise provided greater challenge to postural stability in the AP direction while the HA moved the CoP to a greater extent and provided greater challenge to postural control in the ML direction than the SS.
Varying lower extremity joint angles, kinetics, and characteristics of postural control found during performance of the selected exercises suggest that combinations of these exercises may assist clinicians in tailoring exercise programs. Our results also suggest that postural control demand in the SS and HA may be similar to balance activities often included in falls prevention programs. Thus, clinicians may address falls risk factors related to mobility and balance deficits in older adults by including the selected exercises in a fall prevention program.