Running-Related Muscle Strain Needs Longer Recovery

Return to sport after a calf muscle strain injury may take longer when it is running-related, and there is severe aponeurotic disruption, according to a new study.

Researchers involved in the study, “Return to Play and Recurrence After Calf Muscle Strain Injuries in Elite Australian Football Players,” used clinical and magnetic resonance imaging data to better understand why some athletes take longer to recovery from a calf muscle strain injury. The study was published online on October 8, 2020 in The American Journal of Sports Medicine.

The investigators analyzed data on 149 calf muscle strain injuries pulled from the Soft Tissue Injury Registry of the Australian Football League. Clinical data included age, previous injury history, ethnicity, and the mechanism of injury. Study outcomes focused on return to play and recurrence of index injury.

Overall, the players with calf muscle strain injury with severe aponeurotic disruption (AD) took longer to return to play than the players who didn’t have AD (31.3 ±12.6 days vs. 19.4 ± 10.8 days (mean ±SD; p = .003). This was true regardless of the anatomical location of the injury.

A running-related mechanism was also associated with a longer return to play period (adjusted hazard ratio, 0.59; p = .02).

The researchers also found that early recurrence of the injury was associated with older age (adjusted hazard ratio, 1.3; p = .001) and a history of ankle injury (adjusted hazard ratio, 3.9; p =.032).

Both older age and history of calf muscle strain injury increased the risk of recurrence within two seasons. The index injury MRI findings were not associated with risk of recurrence.

The authors wrote, “A running-related mechanism of injury and the presence of AD on MRI were associated with a longer RTP [return to play] period. Clinical rather than MRI data best indicate the risk of recurrent calf muscle strain injury.”