Key pinch in healthy adults: normative values.

Intra-individual and inter-individual variations of key pinch strength were analysed in a standardised manner for healthy Caucasian adults (female n = 403; male n = 366) aged between 20 and 95 years. The mean strength was less in women (right 6.6 kg; left 6.1 kg) than in men (right 10.4 kg; left 9.7 kg). Independently of hand dominance or gender, the right side was about 7% stronger. Constitutional variables such as forearm length, forearm circumference and hand size showed a positive correlation with key pinch strength. Since the correlation between age and key pinch was similar in both genders, showing a continuous decrease of strength from the fifth decade of life on, key pinch seems independent from gender-specific hormonal changes. In conclusion, we recommend to side adjust measured values and to include information regarding constitutional characteristics for intra-individual comparison.