The effects of neuromuscular electrical stimulation on chronic knee pain and functional performance in older adults with osteoarthritis of the knee

The chronic pain of osteoarthritis of the knee limits functional performance in such simple tasks as getting out of a chair or climbing stairs. The purpose of this study was to examine the effect of neuromuscular electrical stimulation (MMES) as an alternative therapy to diminish chronic pain and increase physical functional performance.; Participants (n = 38) were randomly assigned to either the NMES intervention or the arthritis education groups. The NMES protocol involved 12 weeks of NMES to the quadriceps muscle of the index leg three times per week, 15 minutes per session with amplitude set to achieve up to 40% of isometric maximum voluntary contraction (MVC).; Pain was assessed using the McGill Pain Questionnaire (MPQ), and the Arthritis Impact Measurement Scale 2 - Pain Subscale (AIMS2-PS). Pain intensity 15 minutes after the NMES treatment was assessed using the NMES Pain Diary. Physical functional assessment included the 50 foot timed walk-turn-walk at a normal and fast pace, the timed chair rise, and the timed stair climb.; The repeated measures analysis of variance (ANOVA) found no significant group differences on the MPQ. The analysis of covariance demonstrated no significant group differences on the AIMS2-PS. There was a 22% decline (p < .001) in pain intensity as measured by the NMES Pain Diary. None of the physical functional performance measures showed significant group differences when analyzed using a repeated measures ANOVA. A linear regression of the predictor variables (group, pain, and MVC) on each functional performance significantly explained 28% to 33% of variance. Group explained a non-significant 1–2% of variance. Pain was the only significant predictor of physical functional performance explaining between 20% and 29% of variance.; This study demonstrated an immediate decline in pain through the use NMES—a non pharmacological strategy that can be administered at home by the older adults using a portable electrical stimulator. This study has provided the preliminary support for continuing research into the used of the electrical stimulator among people with osteoarthritis of the knee.