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ASBMR 2008, 2008;

Jumping Mechanography Safely Evaluates Muscle Performance in Older Adults

Jahr: 2008

Buehring B, Valentine S, Woods A, Checovich M, Krueger D, Binkley N
University of Wisconsin, Madison, WI, USA


Neuromuscular function declines with advancing age and is strongly associated with increased risk for falls, hip fractures and decreased quality of life. A variety of tests, e.g., chair-rise or timed-up-and-go, assess muscle function. However, a need exists for more sensitive tools to evaluate interventions designed to enhance neuromuscular performance. Jumping mechanography quantitatively measures an individual’s ability to generate power and correlates with the methods noted above. However, only limited data evaluating the safety of older adults performing maximal countermovement jumps (CJ) on a force platform exists.
As such, this study investigated safety and utility of jumping mechanography in 40 (20 men/20 women), community-dwelling adults over age 60. At baseline, jumping mechanography of two-leg CJ was performed on a force platform (Leonardo, Novotec, Pforzheim, Germany). All participants completed three maximal CJ; maximal jump height [cm] and specific power [W/kg] were calculated. Main outcomes were worsening pain and new vertebral fracture. Pain was assessed using a visual analog pain scale before and immediately after jumping and 7 days later. Bone mineral density (BMD) and vertebral fracture assessment (VFA) were performed using a Lunar iDXA densitometer (GE Healthcare, Madison, WI) prior to CJ and VFA was repeated in 7 days. Stadiometer measured height was obtained at baseline and day 7.
Data were analyzed using linear regression and t-test. Age [mean (±SD, range)] and BMI were 77 (± 9, 63-91) years and 25.5 (± 3.6, 19.4-34.1) kg/m2 respectively. Mean lowest T-score of the L1-4 spine, total femur or femur neck was -1.43 (± 1.1; range +2.4 to -3.1).
At baseline, 7 participants had prevalent fractures; 4 had multiple fractures. Power and jump height were lower in older volunteers and did not differ by gender. Mean jump height in women was 14.4 cm ± 5.8 and 16.4 cm ± 6.8 in men. Mean power in women was 19.2 W/kg ± 5.6 and 21.1 W/kg ± 6.3 in men. Pain was low at baseline and follow-ups, ranging from 0 to 5. Pain was reported by 8 individuals before jumping; after jumping, 4 reported a pain change of 1, two noted new pain, one worsened and one improved. A week later, compared to baseline, 6 reported worsening pain and 6 improved. No height or vertebral fracture status change was observed after jumping. In summary, jumping mechanography demonstrates lower jump height and generated power with advancing age. Additionally, it is safe with no substantial increase in pain or worsening of vertebral fracture status in older adults, including those with low BMD and prevalent vertebral fracture.
Further evaluation of this methodology as a tool to evaluate change in neuromuscular performance of older adults is indicated.

GID: 1529; Letzte Änderung: 19.09.2008