Impact of Lateral Elbow Pain on Pronation and Supination Torques and Influence of Forearm Rotation Angle.

Importance: Lateral elbow pain (LEP) is associated with damage to the accessory rotator muscles of the forearm, but there is little evidence of the effect of LEP on pronosupination torques and its influencing factors.

Objective: To analyze the differences in forearm pronosupination torques between affected and sound limbs in patients with LEP and to investigate the influence of sex, age, dominance, and forearm position.

Design: A cross-sectional study, using a stepwise selection algorithm for analysis of variance, to assess torque variations on the basis of the considered factors.

Setting: Biomechanical analysis laboratory in a university research institute.

Participants: A convenience sample of 36 people with LEP, predominantly middle-aged, with a majority presenting with dominant upper limb involvement.

Outcomes and measures: Torque measurements for pronation and supination in multiple forearm positions.

Results: Participants had significant deficits in pronosupination torques in affected limbs compared with sound limbs, particularly in extreme positions. The largest differences were observed in the supination direction with 60° of forearm pronation and the pronation direction with 60° of forearm supination. Sex and dominance significantly influenced torque production, but age did not.

Conclusions and relevance: The greatest values and differences in torque between sound and affected limbs occurred for extreme rotations of the forearm opposite to the direction of the movement, with significant amplifications on torque reduction for the affected side, nondominant limb, and female patients. Those results can be used to define assessment methods and to design training and evaluation methods that address relevant strength deficits of patients affected by LEP. Plain-Language Summary: Understanding the torque profiles of pronation and supination in lateral elbow pain can provide insights into functional impairments and guide occupational therapy rehabilitation strategies as well as progressive reincorporation into certain activities of daily living and work-related manual tasks. Our findings highlight the importance of assessing forearm movement in rehabilitation settings and emphasize the need for targeted interventions that focus on pronosupination function in patients with lateral elbow pain.