The optimal degree of lateral wedge insoles for reducing knee joint load: a systematic review and meta-analysis

Vitor Ferreira; Rita Simões; Rui Soles Gonçalves; Leandro Machado; Paulo Roriz

doi:10.1186/s40945-019-0068-1

The optimal degree of lateral wedge insoles for reducing knee joint load: a systematic review and meta-analysis

Arch Physiother. 2019 Dec 19:9:18. doi: 10.1186/s40945-019-0068-1. eCollection 2019.

Authors

Vitor Ferreira¹, Rita Simões², Rui Soles Gonçalves³, Leandro Machado⁴, Paulo Roriz⁵

Affiliations

¹ 1School of Health Sciences, ESSUA - School of Health, Edificio 30, University of Aveiro, 3810-193 Aveiro, Portugal.
² Santa Casa da Misericórdia da Mealhada, Aveiro, Portugal.
³ 3Polytechnic Institute of Coimbra, Coimbra Health School, Coimbra, Portugal University of Coimbra, Centre for Health Studies and Research, Coimbra, Portugal.
⁴ CIF2D, LABIOMEP, Faculdade de Desporto da Universidade do Porto, Coimbra, Portugal.
⁵ CIDESD-ISMAI, INESC-TEC, LABIOMEP, Coimbra, Portugal.

Abstract

Background: Lateral wedge insoles are traditionally used to reduce the adduction moment that crosses the knee during walking in people with medial knee osteoarthritis. However, the best degree to reduce knee joint load is not yet well established.

Methods: Electronic databases were searched from their inception until May 2017. Included studies reported on the immediate biomechanical effects of different degrees of lateral wedge insoles during walking in people with knee osteoarthritis. The main measures of interest relating to the biomechanics were the first and second peak of external knee adduction moment and knee adduction angular impulse. For the comparison of the biomechanical effects of different degrees of insoles, the studies were divided in three subgroups: insoles with a degree higher than 0° and equal to or lower than 5°; insoles higher than 5° and equal to or lower than 9°; and insoles higher than 9°. Eligible studies were pooled using random-effects meta-analysis.

Results: Fifteen studies with a total of 415 participants met all eligibility criteria and were included in the final review and meta-analysis. The overall effect suggests that lateral wedge insoles resulted in a statistically significant reduction in the first peak (standardized mean difference [SMD] -0.25; 95% confidence interval [CI] -0.36, - 0.13; P < 0.001), second peak (SMD -0.26 [95% CI -0.48, - 0.04]; P = 0.02) and knee adduction angular impulse (SMD -0.17 [95% CI -0.31, - 0.03]; P = 0.02). The test of subgroups found no statistically significant differences.

Conclusion: Systematic review and meta-analysis suggests that lateral wedge insoles cause an overall slight reduction in the biomechanical parameters. Higher degrees do not show higher reductions than lower degrees. Prior analysis of biomechanical parameters may be a valid option for selecting the optimal angle of wedge that best fits in knee osteoarthritis patients with the lowest possible degree.

Keywords: External knee adduction moment; Knee; Lateral wedge insoles; Meta-analysis; Osteoarthritis.

Publication types

Review