The influence of different non-articular proximal forearm orthoses (brace) widths in the wrist extensors muscle activity, range of motion and grip strength in healthy volunteers

Article type: Research Article

Authors: Marcolino, Alexandre Márcio^{a; b; *} | Fonseca, Marisa de Cássia Registro^b | Leonardi, Naiara Tais^c | Barbosa, Rafael Inácio^{a; b} | Neves, Lais Mara Siqueira das^c | de Jesus Guirro, Rinaldo Roberto^b

Affiliations: [a] Federal University of the Santa Catarina, Campus Araranguá-SC, Brazil | [b] Rehabilitation and Functional Performance Post-Graduate Program, Ribeirão Preto of the Medical School, University of São Paulo, Ribeirão Preto, Brazil | [c] Rehabilitation and Functional Performance Post-Graduate Program, Department of Biomechanics, Medicine and Rehabilitation of the Locomotor Apparatus, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil

Correspondence: [*] Corresponding author: Alexandre Márcio Marcolino, Rehabilitation and Functional Performance Post-Graduate Program, Department of Biomechanics, Medicine and Rehabilitation of the Locomotor Apparatus, Ribeirão Preto Medical School, University of São Paulo, Avenida Bandeirantes, 3900, Ribeirão Preto, São Paulo, CEP 14049-900, Brazil. E-mail:ammfisio@usp.br

Abstract: PURPOSE: The purpose this study was perform a biomechanical evaluation to compare the influence of commercial models of different non-articular proximal forearm orthoses widths (2.5 cm, 5.5 cm, 7.5 cm and 12.0 cm) in the extensor muscle activation, range of motion and grip strength in healthy subjects. METHODS: Was analyzed data from extensor carpi radialis, extensor carpi ulnares and extensor digitorum comunis using surface electromyography, simultaneous with a wrist electrogoniometer MiotecTM and a hydraulic dynamometer JamarTM. The sequence of tests with all the commercial orthoses models was randomized. Statistics analyses were performed by linear model with mixed effects. RESULTS: According to our findings the non-articular proximal forearm orthoses (2.5 cm - narrowest) positioned close to lateral epicondyle provided lesser muscle activation on extensor carpi radialis brevis/longus and extensor digitorum comunis, decreased wrist extension and grip strength during submaximal grip task (p< 0.01). CONCLUSIONS: A narrow non-articular proximal forearm orthosis positioned close to the lateral epicondyle might decrease the extensor muscle activation and therefore could reduce mechanical stress on its insertion, based on this sample. Clinical studies must be conducted to confirm these findings.

Keywords: Orthoses, brace, lateral epicondylitis, electromyography, wrist biomechanics

DOI: 10.3233/BMR-160727

Journal: Journal of Back and Musculoskeletal Rehabilitation, vol. 30, no. 1, pp. 145-151, 2017