Exercise interventions for preventing and treating low bone mass in the forearm: A systematic review and meta-analysis

Abstract

Objective: To examine the effectiveness of exercises for improving forearm bone mass. Data Sources: MEDLINE, EMBASE, CINAHL, AMED, Web of Science, and Cochrane CENTRAL were searched from their inception until December 2018. Study Selection: Eligibility included adults undertaking upper limb exercise interventions (≥12wk) to improve bone mass. Data Extraction: Screening of titles, abstracts, and full texts and data extraction were undertaken independently by pairs of reviewers. Included studies were quality appraised using Cochrane risk of bias tool. Data Synthesis: Exercise interventions were classified into “resistance training” of high or low intensity (HIRT/LIRT, respectively) or “impact.” Random-effects meta-analysis of the percentage change in forearm bone mass from baseline was conducted. Twenty-six studies were included in the review, of which 21 provided suitable data for meta-analysis. Methodological quality ranged from “low” to “unclear” risk of bias. Exercise generally led to increases (moderate-quality evidence) in forearm bone mass (standard mean difference [SMD], 1.27; 95% CI, 0.66-1.88; overall effect Z value=4.10; P<.001). HIRT (SMD, 1.00; 95% CI, 0.37-1.62; Z value=3.11; P=.002), and LIRT (SMD, 2.36; 95% CI, 0.37-4.36; Z value=2.33; P<.001) led to moderate increases in forearm bone mass. Improvements resulting from impact exercises (SMD, 1.12; 95% CI, −1.27 to 3.50; Z value=0.92; P=.36) were not statistically significant (low-quality evidence). Conclusions: There is moderate-quality evidence that exercise is effective for improving forearm bone mass. There is moderate-quality evidence that upper body resistance exercise (HIRT/LIRT) promotes forearm bone mass but low-quality evidence for impact exercise. Current evidence is equivocal regarding which exercise is most effective for improving forearm bone mass.