Neuromuscular Electrical Stimulation
A study of the use of home-based neuromuscular electrical stimulation (NMES) for the purpose of improving quadricep strength in older adults with knee osteoarthritis has produced promising results.
Osteoarthritis, often referred to as "wear-and-tear" arthritis, can be helped by improving the muscle strength around the joint or joints involved. Exercise has been shown to improve the symptoms, severity, and disability associated with osteoarthritis of the knee. However, exercise can also have the consequence of muscle damage in sedentary adults, especially women.
Neuromuscular electrical stimulation was studied as a treatment option for osteoarthritis by Dr. Laura Talbot from The Johns Hopkins University. NMES is achieved by sending small electrical impulses through the skin to the underlying motor units (nerves and muscles) to create an involuntary muscle contraction. Thirty-four adults with radiographically (x-ray) confirmed symptomatic knee osteoarthritis were involved in the study. The study participants were randomly given standard arthritis education (12-week Arthritis Self-Management Course) with or without NMES. The NMES group used a portable electrical muscle stimulator 3 days a week for quadricep training and strengthening. Over 12 weeks, the intensity of isometric contraction was increased incrementally to 30-40 percent of maximum.
The primary outcome was isometric quadriceps femoris (QF) torque. Secondary outcomes included:
- daily step counts
- total activity vector magnitude
- 100-foot walk-turn-walk
- timed stair climb
- chair rise
- pain level
The results indicated that:
- The stimulated-knee extensor showed a 9.1 percent increase in 120 degree QF peak torque compared to a 7 percent loss in the education only group.
- The chair rise time decreased by 11 percent in the NMES group, while the education only group had a 7 percent reduction.
- Both groups improved their walk time by about 7 percent.
- Severity of pain reported following intervention (either NMES or education) did not differ between groups.
The research team led by Talbot concluded that a home-based NMES treatment plan appears promising for increasing quadriceps femoris strength in adults with knee osteoarthritis without making arthritis symptoms worse.
Sources: The Journal of Rheumatology, July 2003: A Home-Based Protocol of Electrical Muscle Stimulation for Quadriceps Muscle Strength in Older Adults with Osteoarthritis of the Knee; Electrical Muscle Stimulation Helps Knee Arthritis, July 24, 2003, Reuters Health