I have previously written a blog (found here) that goes through a detailed assessment and differential diagnosis using clinical examination techniques of hip and groin pain. This blog will go through evidence based treatment, rehabilitation and prevention of adductor related groin pain.
Looking throught the available literature only 2 randomised controlled trials (RCT’s) were found that deal with treating adductor related groin pain.
Holmich et al (1) performed a RCT on 59 participants that were randomized to receive either active treatment which involved strength training of the adductor, abdominal, and low back muscles combined with coordination and balance exercises, or passive treatment which involved manual therapy, electrotherapy and stretching. It was published in the Lancet (every researchers dream!). The outcomes were assessed by the following criteria: no pain at palpation of the adductor tendon and insertion points; no groin pain during resisted adduction; no groin pain during or after athletic activity in the same sport and return to the same sport and at the same level without groin pain. If all 3 measures were met, the result was labeled excellent; if 2 measures were met, the result was labeled good, if 1 measure was met the result was labeled fair and if no measures were met, the result was poor. 23 (79%) of those in the active-treatment group had an excellent outcome versus 4 (13%) of those in the passive-treatment group (p=0.001).
In a 8-12 year follow up of this original study by Holmich et al (2), that used forty-seven (80%) of the original 59 subjects, were examined by the same physician using the identical protocol to the one used in the original study. During the follow-up period, most of the athletes had reduced their athletic level; however, this did not differ between the 2 treatment groups. The follow-up trial demonstrated 12 (50%) of the athletes in the active-treatment group had an excellent result compared to 5 (22%) in the passive-treatment group (p=0.047). The association was even stronger in the subgroup of soccer players tested where 11 (55%) of athletes in the active-treatment group had an excellent result compared with 3 (16%) in the passive-treatment group.This study implies that an active training program can make a difference in the long run, but it is unclear why this would be the case. The authors did not assess whether the athletes in the active treatment group continued any of the exercises shown to them during the training session in the years to follow as is commonly recommended after a physical therapy program. It is also unclear whether or not any of the athletes had recurrence of their groin symptoms during the follow-up period that may have resolved by the time the data was assessed. However this does suggest that a supervised core program and muscle-specific strengthening can have a beneficial impact on the treatment of chronic, overuse injuries in the short and long term.
Weir et al (3) recruited 53 male athletes and one female athlete aged between 18 and 50 years. The study compared multi-modal treatment (MMT) (consisting of heat followed by manual therapy and stretching of adductor muscles and a return to running program) with exercise therapy (the same as Holmich et al, 1999) that was home based with supervision every 2 weeks, instead of fully supervised (1). At all times athletes were instructed to stop exercising if they experienced groin pain. The outcomes assessed at 16 weeks were ’successful treatment’, maximum pain during sports, return to sports at the same level without groin pain, time to return to sports, and adverse effects. The only difference found was athletes receiving multi-modal treatment returned on average 4.5 weeks earlier than those treated by exercise therapy (p=0.043). This difference between the groups could be explained by the return to running program (4) starting four weeks earlier in the MMT group compared with the exercise therapy group due to the intervention taking less time to complete. The lack of a control group examining different components of the MMT makes it impossible to ascertain which part of the program may help in the treatment.
More recently Thorborg et al (5) rehabilitated a soccer player that ruptured both of their adductor longus muscles. They used the same protocol used by Holmic et al (1) but also included additional strengthening exercises with an eccentric emphasis, using strength training machines, for the hip adductors, abductors, flexors and abdominal muscles. This strength training with mschines was started 10 weeks post injury with a relative load of 20 repetitions maximum (RM) progressing into 15, 12 and 10 RM, when these loads could be tolerated pain free. Return to a soccer match was not advised until all soccer-specific activities could be performed pain-free, with no aggravation of symptoms the following day(s), and when hip adduction strength difference between injured and uninjured leg was <5%. They found hip adduction strength was restored after 1 year for one rupture, and after only 10 weeks for the other rupture. They also found no new or recurrent injuries occurred in the hip or groin region after 2 and 3 years from the initial adductor ruptures in each leg with these return to play guidelines and additional eccentric strengthening exercises.
Clinical Implications of the Evidence
The participants were predominantly young male athletes; with only one female used in the studies. Therefore the evidence cannot be generalized for both genders because of their anatomical and physiological differences. The evidence is strengthened by the consistency in the population, the exercise intervention and outcome assessment’s used. However, ’successful treatment’ as defined in these two trials is a non-validated measure. Despite the limited evidence, exercise therapy based on strengthening and co-ordination exercises appears to be more effective than a more passive treatment (stretching, electrotherapy and transverse friction massage) (1) especially with the positive outcomes shown 8-12 yeas later (2). Althouh Weir et al (3) found a significantly quicker return to play in a multi modal treatment group using manual therapy compared to the Holmich et al (1) exercise protocol, they used a return to running exercise program (4) earlier in this group which could have caused the positive results.
Groin Injury Prevention
Weakness in the hip adductors compared to the abductors has been shown to be a risk factor for getting groin pain in soccer, rugby league, ice hockey and AFL athletes (6-9). Strengthening the adductors is therefore extremely important and Jensen et al (10) has looked at the effect of an 8- week hip-adductor strengthening programme, using one hip-adduction exercise with elastic bands for resistance. They used sub-elite soccer players (n=34) performing two training sessions per week (weeks 1–2) with 3×15 repetition maximum loading (RM), three training sessions per week (weeks 3–6) with 3×10 RM and three training sessions per week (weeks 7–8) with 3×8 RM. Repetitions used a 3 sec concentric, 2 sec isometric hold and 3 sec eccentric contraction speeds through full hip abduction to back next to the opposing leg. Eccentric hip-adduction (EHAD), isometric hip-adduction (IHAD) and isometric hip-abduction (IHAB) strength, and the IHAD/IHAB ratio were measured by handheld dynamometry. Results showed the training group EHAD strength increased by 30% ( p<0.001). In the control group, EHAD strength increased by 17% (p<0.001), but the increase was significantly larger in the training group compared with the control group (p=0.044). No other significant differences in IHAD, IHAB or the IHAD/IHAB ratios were found. The relevant and significant increase in eccentric hip-adduction strength found may have implications as a promising approach towards groin injury prevention in soccer.
Recently Serner et al (11) investigated muscle activity of adductor longus during 8 hip adduction exercises, and they additionally analysed muscle activation of gluteals and abdominals in 40 male elite soccer players. The graph below shows the exercises in adductor longus activation order from high to low. This can be used as a guide for exercise prescription in different stages in strength and rehabilitation.
Adductor related groin pain is one of the most common injuries seen in sport. The evidence regarding appropriate treatment is limited to only two RCT’s which suggest hip adductor and abdominal strengthening along with a return to running exercise intervention are the best available treatment methods. Manual stretching techniques were also shown to be beneficial in improving return to play but the exact techniques or whether the technique combined with the Holmich et al (1) protocol is more effective is unknown. The evidence is also lacking in the fact that only one female participant was used and no validated outcome measures such as the HAGOS were used. But until more research or repeat RCT’s are done the outlined interventions are the best available. Preventing these injuries also requires increasing hip adductor strength to match the abductors which highlights the importance of accurate dynamometry measures being vital in return to play conditions. A simple method using elastic bands has proven to improve eccentric adductor strength (10), but personally I feel a study investigating whether the copenhagen adduction exercise can reduce groin injuires in a prospective trial could provide better outcomes then have been shown before. This is because this exercise has high adductor longus as well as abdominal musculature activation (shown in the graph above) (11). Both of thee factors are important factors in rehabilitating these injuries. As always I welcome any feedback or comments regarding personal experiences of dealing with this type of injury and look forward to hearing back from you.
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Hölmich P, Nyvold P, & Larsen K. Continued significant effect of physical training as treatment for overuse injury: 8- to 12-year outcome of a randomized clinical trial. The American Journal of Sports Medicine, 2011; 39 (11), 2447-51.
Weir A, Jansen JA, van de Port IG, van de Sande HB, Tol JL, Backx FJ. Manual or exercise therapy for longstanding adductor-related groin pain: a randomised controlled clinical trial. Manual Therapy 2011;16(2): 148–54.
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Thorborg K, Petersen J, Bachmann M and Hölmich P. Clinical recovery of two hip adductor longus ruptures: a case-report of a soccer player, BMC Research Notes, 2013; 6:205.
Crow JF, Pearce AJ, Veale JP, et al. Hip adductor muscle strength is reduced preceding and during the onset of groin pain in elite junior Australian football players. J Sci Med Sport 2010;13:202–4.
Engebretsen AH, Myklebust G, Holme I. Intrinsic risk factors for groin injuries among male soccer players: a prospective cohort study. Am J Sports Med, 2010;38:2051–7.
O’Connor D. Groin injuries in professional rugby league players: a prospective study. J Sports Sci 2004;22:629–36.
Tyler TF, Nicholas SJ, Campbell RJ. The association of hip strength and flexibility with the incidence of adductor muscle strains in professional ice hockey players. Am J Sports Med 2001;29:124–8.
Jensen J, Hölmich P, Bandholm T, Zebis MK, Andersen LL, Thorborg K. Eccentric strengthening effect of hip-adductor training with elastic bands in soccer players: a randomised controlled trial, Br J Sports Med 2014;48:332–338.
Serner A, Jakobsen MD, Andersen LL, Hölmich P, Sundstrup E, Thorborg K. EMG evaluation of hip adduction exercises for soccer players: implications for exercise selection in prevention and treatment of groin injuries, Br J Sports Med 2014;48:1108–1114.