Figure 1: (a) Age analysis for shoulder flexibility in men. Piecewise linear regression s-segment model shows breaking at the age of 71 years. Rate of decline prior to age 71 is −0.20 degrees per year and −0.80 degrees per year after the age of 71 years. ( of fit ). (b) Age analysis for shoulder flexibility in women. Piecewise linear regression s-segment model shows breaking at the age of 63 years. Rate of change prior to age 63 is 0.38 degrees per year and −0.74 degrees per year after the age of 63 years. ( of fit ).