Cameron Lee, “Grip Strength and Percentage Change Over the Lifespan: NIH Toolbox”
Mentor: Inga Wang, Occupational Therapy, Science & Technology, Rehabilitation Sciences & Technology (School of)
Oral Presentation: 9:15am Union E280
Grip strength (GS) is a potential biomarker of aging. This study examined rate of change, and percentage change—relative to reference age (19–20 years) across the lifespan (ages 3-85). This is a cross-sectional, observational study, and includes a general community-based sample. Data was drawn from the 3,901 noninstitutionalized U.S. residents who participated in the NIH Toolbox study. We computed (a) rate of change (kg/year) to track grip strength trajectories, and (b) percentage change (%) to quantify variation across age groups, gender, and hand dominance. GS across sexes increase rapidly, peaking at age 14 for males (4.58 kg/yr) and age 11 for females (2.87 kg/yr). After this peak, the rate of change declines nearing zero at age 19–20 (-0.69 kg/yr in males, -0.06 kg/yr in females). GS progressively declines and at age 60, males experience a rate of change of -0.35 kg/yr and females -0.30 kg/yr, stabilizing at -0.35 to -0.37 kg/yr in males and -0.27 to -0.28 kg/yr in females from ages 66–85, reflecting a steady decline in muscle strength. GS percentage change improves turning positive at age 18 (0.30% in males, 0.45% in females), peaking at age 19 for males (0.60%) and age 23 for females (0.65%). Decline begins after age 26 in males (-0.09%) and age 45 in females (0.99%). The decline accelerates further, with percentage losses of -33.27% in males and -37.62% in females by age 85. These trends highlight a continuous and significant age-related reduction in muscle strength, particularly in older adults. The reference values for the rate of GS decline during normal aging are essential for distinguishing healthy aging from early signs of muscle dysfunction. These values are benchmarks to assess whether an individual’s decline is within the expected range or indicates a higher risk of frailty, sarcopenia, or other age-related conditions.