Characteristics of Physical Performance	

Isometric quadriceps force has been shown to be significantly impaired in GH-deficient adults when compared with carefully matched controls; however, although data from other muscle groups have shown a reduction in force, this was not statistically different. Following GH replacement therapy, none of the double-blind studies has so far been able to demonstrate a statistically significant increase in force, despite significant increases in thigh cross-sectional area (probably because of a ‘type II’ error). Longer-term but uncontrolled follow-up has, however, been able to demonstrate an increase in quadriceps force when therapy has been continued for over twelve months.