[Reliability of global interdigital pinch (vice pinch) dynamometral values measured by Microfet 2]

To study test-retest reliability of pinch grip strength with a two-month gap in three upper limb positions. To study factors causing variability of peak force.

Forty healthy control volunteers, sex-ratio 1, mean age 36.6 years (sd = 9.9), were separated into four groups of ten persons. The Microfet 2 dynamometer was used to measure peak force developed during pinch grip. The measurements were made in three positions: upper limb parallel to body, arm flexed at 90 degrees and during the Roos manoeuvre. Test-retest reliability was evaluated after two months. Statistical analysis used the correlation test (p = 0.05).

Reliability proved to be excellent in all three positions and in all four groups. Dynamometer values were stable between the beginning and end of the Roos manoeuvre in this healthy population. There were no significant differences between peak force measured in the three positions and between left and right upper limbs.

The Roos manoeuvre gives a stable and reliable result in a population without thoracic outlet syndrome. Dynamometer tests are also reliable in the usual upper limb positions, in accordance with other studies.

This dynamometric test should be useful in assessing the severity of thoracic outlet syndrome and in demonstrating the therapeutic efficacy of different treatments.