Measurement of isometric wrist muscle strength - a systematic review of starting position and test protocol

Background: Isometric strength of the wrist musculature is frequently used in the clinical setting as a primary outcome measure following a wrist disorder. Objective: A systematic search of the literature was undertaken to review published starting positions and test protocols used in assessing isometric strength of the wrist musculature. Methods: AMED, CINAHL, Current Contents, EMBASE and MEDLINE computerized databases were searched for literature published between January 1980 and September 2002 that described the methodologies used to assess isometric wrist muscle strength. Papers were excluded if they explored motor unit recruitment, strength was assessed via manual muscle testing or no information regarding starting position or test protocol was included. Results: A total of 15 papers met the inclusion criteria. Starting position varied between papers, with little justification for the positions assumed. Test protocols used also were variably described, with some not meeting accepted standards for the assessment of isometric strength. Many of the reports lacked information regarding starting position and test protocol used, which precluded replication of the methodology. Conclusions: Further research is required to determine the optimum starting position and test protocol for the assessment of isometric wrist muscle strength. These should subsequently be assessed for reliability, to ensure that consistent results are produced over different occasions of testing.