Loss of strength can be a part of any illness but especially cancer. A new study published in the Journal of Neurophysiology concluded that regular imagery exercises help preserve arm strength during 4 weeks of immobilization such as happens when a patient is in a cast. In the study researchers measured wrist flexor strength in 3 groups of healthy adults. Twenty-nine people wore a rigid cast extending from just below the elbow past the fingers that effectively mobilized the hand and wrist for 4 weeks. Fifteen additional subjects did not wear a cast and served as a control group.
In the group who wore the wrist-hand immobilization cast half were asked to regularly perform an imagery exercise, imagining they were contracting their wrist for five seconds and then resting for 5 seconds. They were verbally guided through the exercise with thede instructions: “Begin imagining that you are pushing in as hard as you can with left wrist, push, push, push and stop. Then a five second rest. Start imagining that you re pushing in again as hard as you can, keep pushing, keep pushing….and stop. Another five second rest. This was repeated four times in a row followed by a 1 minute break for a total of 13 rounds per session and five sessions per week. The second wrist-hand immobilization group performed no exercises.,
At the end of 4 weeks both groups with the hand-arm immobilization had lost strength compared to the control group. However, the group that performed imagery exercises lost 50% less strength than the non-imagery group(24% vs 45% respectively). In addition, the nervous system’s ability to activate the muscle also rebounded more quickly in the imagery group compared to the non-imagery group.
Researchers concluded that findings suggest neurological mechanisms contribute to disuse-induced weakness, and that regular activation of the cortical regions of the brain via imagery attenuate the weakness and recommend visualizatiuon to prevent musclke weakness.