Exercise Training Reduces Groin Injury Recurrence for Years

Nancy A. Melville

August 13, 2011

August 13, 2011 — Treatment for overuse injuries of the groin that focuses on a specific exercise training regimen shows sustained long-term improvement as long as 12 years after treatment, according to a study published online August 3, 2011, in the American Journal of Sports Medicine.

The follow-up study of 47 of 59 athletes who participated in an original randomized controlled trial in Denmark indicated that those who received an active treatment of specific exercises targeted to their groin injury, compared with those in a passive training group, continued to demonstrate a significant effect from the training at the follow-up 8 to 12 years later (P = .047).

Thirty-nine of the participants were soccer players (83%), and those athletes showed an even greater level of a sustained improvement (P = .012).

There were no significant differences in improvement according to age, present sports activity, reasons for activity reduction, or the amount of time to follow-up. The median age of participants in the follow-up study was 42.5 years for the active treatment group and 42.8 years for the passive group.

The original training program addressed long-standing adductor-related groin injuries with exercises that focused on adductor, abdominal, and lower back muscles, combined with coordination and balance exercises.

The training program was found to be highly effective in the original study, with 79% of athletes in the active group returning to their previous level of sport without any groin pain, compared with just 14% of those in the control group.

The sustained benefit from the training program as long as 8 to 12 years later is particularly notable due to the nature of the treatment, the researchers said.

"This is, to our knowledge, the first time the effect of an exercise treatment for overuse injuries to the musculoskeletal system has been shown to be long lasting (8-12 years)," they wrote. "This is an important quality of any treatment, but in this case, it is even more encouraging that a noninvasive and nonpharmacological method has this ability."

The researchers speculated that one reason for the long-lasting improvement could be that the strengthening of the abductor and particularly the adductor muscles address the unique physical stresses that soccer puts on the body.

"Eccentric hip strength is important for fundamental skills in soccer, such as kicking, accelerating, and sudden change of direction, and soccer-relevant diagonal kicking angles seem to increase the demands of hip adduction strength of the kicking leg," they wrote.

"This adds to the explanation for the frequent adductor-related problems and to why the specific strengthening of the femoral adductor muscles, including static, concentric, and eccentric exercises in the active treatment, could be an important part of the long-standing effect."

The specific exercise treatment in the primary randomized controlled trial focused on controlling the complexities of the position and motion of the pelvis, which also likely had a benefit, the study authors explained .

"The synergies between the muscles acting across the pelvis, sacroiliac joints, and hip joints are determining to allow optimum production, transfer, and control of force and motion to the terminal segment in integrated athletic activities," the study authors wrote.

"The excellent result of the primary [active treatment] and the lasting effect after 8 to 12 years could be attributed in part to this specificity in enhancing muscular strength and endurance as well as neural control."

Limitations of the study included a lack of knowledge of the participants' activities during the 8- to 12-year follow-up regarding supplementary treatment or physical activity.

With the high risk of recurrence of overuse injuries, however, the results offer convincing evidence that specific exercise training can play an important role in reducing recurrence, the study authors concluded.

"The present results indicate that this risk can be reduced in the case of long-standing adductor-related groin pain, and further studies must show whether the principles of the present treatment program can be successfully applied to other injuries."

The study authors have disclosed no relevant financial relationships.

Am J Sports Med. Published online August 3, 2011.