New Study: Strengths Improves (!) After Injury

A new study published in the January issue of Sports Medicine suggests that a secondary loss of muscle strength typically does not occur after the initial muscle injury. The researchers sought an answer to the debate over the degradative quality of muscle injuries.

According to Gordon L. Warren, Ph.D., FACSM, distinguished university professor of the department of physical therapy, Byrdine F. Lewis School of Nursing and Health Professions at Georgia State University in Atlanta, Georgia, “…an immediate loss of strength accompanies nearly all types of skeletal muscle injury, but there is debate whether the strength loss worsens over the first few days after injury. This is important to know because it influences injury treatment.”

Warren and colleagues analyzed strength data from 223 studies published between 1985 and 2012 with over 4,000 human and animal subjects. The data from each study was converted to a standard format and reported as effect size (ES).The researchers found a small-to-medium positive overall effect size (ES) statistically greater than zero (overall ES = +0.34; p < 0.00000001). A negative ES statistically less than zero would have indicated a secondary loss of strength.

Warren told OTW their main finding was that “…after the initial injury, strength on average does not decrease, but instead improves over the first three days.”

He added, “Our findings argue against the degradative processes spreading to parts of the muscle that were not damaged initially and then in turn causing additional (or secondary) damage. Our findings suggest that caution should be taken when treatments are implemented in the first few days after a muscle injury because they may be contraindicated. They may actually impair the recovery from injury.”