Fig 2. Measurements of leg-extensor (LE), sensor-based stair ascent (SA) and sensor-based sit-to-stand (STS) power in healthy adults (N = 92–96, age 20–70 years).

The overall average age-related decline is represented by a solid linear fit for leg-extension, a dotted linear fit for stair ascent and a dot-dashed linear fit for sit-to-stand. Men are presented in black, women in grey. Data are displayed on a log scale.