Biology of Humans 6th Edition by Judith Goodenough,Betty McGuire

Exercise 9

The excerpt below is from an article Cari Romm wrote in The Atlantic. 1 The entire article can be found at: www.theatlantic.com/health/ archive/2015/01/muscle-strength-is-in-the-mind/384361/ "In a small study recently published in the Journal of Neurophysiology2, researchers found that much of muscle strength is based on brain activity, rather than on the mass of the muscles themselves. Researchers at Ohio University's Musculoskeletal and Neurological Institute, 29 volunteers had their non-dominant arms placed in elbow-to-finger casts for four weeks. (Fifteen others acted as a cast-free control group.) Of the 29, 14 were asked to perform mental-imagery exercises five days a week, imagining themselves alternately flexing and resting their immobilized wrists for five second intervals. When the casts came off at the end of the four weeks, both groups had lost strength in their arms-but the group that had imagined themselves doing the arm exercises lost significantly less, measuring an average of 25 percent weaker than at the start of the study, compared to 45 percent for the group that hadn't taken part in the mental-imagery activities."
Do the experimental design and results support a conclusion that mental imagery of exercising can reduce the loss of muscle strength due to immobilization