Abstract
The aim of this paper is to determine inter-reliability, concurrent validity, and interchangeability of the SMS HG dynamometric system and a Jamar digital dynamometer for hand grip strength measurements performed in two relevant positions of the elbow joint, i.e. 90 ° flexion and 180 ° (full) extension. The sample in this research consisted of 61 participants and included 27 women and 34 men. Statistically significant differences in the results found between two positions in the elbow joint indicate that the results must be evaluated separately. However, regarding both testing positions, i.e. 90 ° flexion and 180 ° extension in the elbow joint, it was determined that SMS HG and Jamar instruments have a very high level of inter-reliability (ICC 0.948 to 0.980), but lack concurrent validity. The established mean difference of the results was higher for the 90 ° than for the 180 ° position but in both cases was considered to have a practical significance, thus not supporting the interchangeability of the instruments.