Working Out The Wobbly Knees

Knee osteoarthritis and instability improved with general and specific knee exercises

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News)
Muscle strength is key to helping wobbly knees become more stable. And you have to exercise to get that muscle strength. But whether or not the exercise focuses on the knees might not matter.

General exercise programs improved pain levels and stability in the knees just as well as exercises that target that joint in patients with unstable knees, a recently published study found.

The general programs strengthened muscles and retrained individuals on how to do their daily activities.

Exercise that specifically targeted knee stability and osteoarthritis did not seem to have any extra value, according to the researchers.

"Ask a PT about exercises to strengthen knee stability."

Jesper Knoop, MSc, PT, from the Amsterdam Rehabilitation Research Center, Reade in the Netherlands, led a team of researchers in comparing the ability of two exercise programs to increase activity in patients with knee osteoarthritis (OA) and unstable knee joints.

The study included 159 participants who had osteoarthritis in the knees or knee instability. They were recruited through advertisements in local and regional newspapers between February 2009 and March 2011.

Participants were between 40 and 75 years of age and had self-reported or diagnosed knee instability, as defined by weak muscles, impaired body awareness or improper alignment of the knees.

The participants were randomly divided into one of two groups that underwent a supervised exercise program for 12 weeks. The researchers did not know which participants were receiving which exercise program.

Exercises focused on muscle strengthening and training of daily activities. The first group performed exercises that targeted stabilizing the knee joint while the second group's exercises were more general.

Each participant's activity limitations, pain and knee stability were tracked. Participants who had knee replacement surgery, other forms of arthritis, related illnesses that impaired mobility or severe knee pain were excluded from the study.

The exercise programs for both groups consisted of two 60-minute weekly sessions and an at-home exercise program for five days weekly. The intensity of the training, weight placed on the knee and exercise difficulty were gradually increased.

In the knee-specific exercise group, exercises focused on stabilizing the knee during the first four weeks of training. The exercises were low intensity with minimal load, or weight, placed on the knees, including one week in a swimming pool, which also minimizes loading.

Weeks 5 through 8 targeted muscle strength in addition to maintaining knee stabilization, and the last four weeks added daily activities to the previous exercises.

The researchers found that activity limitations, knee instability and pain decreased in both groups by about 20 to 40 percent.

The degree to which exercises affected the participants' physical function did not change between the two groups.

The knee-specific exercise group perceived that their treatment helped them significantly more than the general exercise group who had the more general exercises.

"In this study, we determined the additional effect of initial knee joint stabilization training, prior to strength training and training of daily activities, in persons with knee OA suffering from knee instability," the researchers wrote in their report. "We could not confirm our hypothesis that specific knee joint stabilization training has additional value in this targeted subgroup of patients, as both treatment groups demonstrated similarly large and clinically relevant improvements on activity limitations, pain and knee instability."

About 78 percent of the knee-specific exercise group and 77 percent of the general exercise group reported their knee symptoms remained stable or improved six months after the exercise programs.

No serious complications or adverse effects were reported by either group.

Jim Crowell, head trainer and co-owner of Integrated Fitness and a dailyRx Contributing Expert, believes that consistently working total body flexibility and strength will have major positive implications on a person's stability throughout their entire body.

"When we work with people who are in need of better knee stability we certainly do knee stabilization exercises but we never solely do those," he said. "We make sure that we are working on their flexibility both upstream and downstream in their ankles, calves, hamstrings, quads, and hips, to name a few."

The researchers noted they were able to guess the group that participants were a part of almost 60 percent of the time.

In addition, the training intensity was slightly different in favor of the group performing exercises not specific to stabilizing the knee.

The study, funded by the Dutch Arthritis Association, was published online May 28 in the journal, Osteoarthritis and Cartilage. No financial conflicts of interest were reported.

Reviewed by: 
Review Date: 
June 5, 2013
Last Updated:
August 7, 2013