Validation of a Practical Forearm Supination Strength Measurement Technique in the Large Sample Cohort

Introduction: The strength of forearm in pronation and supination (P/S) is an important clinical assessment during pre-operative examination as well as in post-operative evaluation. Many clinical trials concerning the measurement of forearm P/S strength were performed using a dynamometer fixed on the wall. The aim of this study was to bring out a simple and reliable technique for the measurement of P/S strength using a dynamometer manually supported and stabilized by an examiner. We hypothesized that there are no differences in evaluation of elbow P/S strength using the dynamometer fixed or the dynamometer stabilized by an operator in healthy people.

Methods: The study was performed on a cross-sectional cohort of 100 healthy subjects without any history of injuries or previous surgery of the upper limbs. Isometric forearm P/S strengths were measured on the dominant and non-dominant forearms, using the dynamometer fixed on a table, and using the same dynamometer kept by an operator. The measurements were repeated in triplicate at 45°, 90° and 120° of elbow flexion in both upper limbs for all patients.

Results: A total of 100 subjects (50 females, 50 males) were included in the study group. The mean age was 46.5 years (range 25-52 years). Female and male subjects showed no significant differences concerning the mean age (F/M ratio 0.50/0.50). The mean body mass index of all participants was 24.34 ± 3.66 kg/m².No significant statistics difference was reported between the P/S strength measured using the two detection methods in our study group (45°, 90° and 120° of elbow flexion and both upper limbs).

Conclusion: The manually stabilized technique is a valid and reliable technique to assess the P/S strength of the forearm. This is a simple and effective method that may be reproduced in our daily clinical practice as well as in sportive practice.