Investigators from Copenhagen University Hospital published a new study this year on the use of elastic bands to strengthen the hip adductor muscles in soccer players.
The goal of the study was to investigate the effect of 8 weeks of elastic band exercise on adductor strength. Weak hip adductors (the muscles in the inner and upper-inner thigh) may increase the risk of adductor strains/groin strains. Jensen, Holmich, Bandholm, et al state: “…increasing hip-adduction strength may decrease the stress put on the hip-adductor muscle-tendinous complex, and prevent overuse injuries and acute tears.”
The authors of this randomized controlled trial were able to show that, in NORMAL SUBJECTS, 8 weeks of eccentric elastic band exercise produced a significant gain in hip-adduction strength compared with a control group. The exercises are simple to perform and can be done at the soccer field, training room, hockey rink or football field.
Previous studies on eccentric exercise have shown a THERAPEUTIC value of these exercises for hamstring strains, patellar tendinitis and achilles tendinitis. While unproven, I suspect that eccentric exercise will be shown to be of therapeutic value for the adductors/”groin” as well.
In our sports medicine center we are concerned with long term prevention through rehabilitation, but also short term pain relief so that our athletes get on an earlier path to rehab, and therefore an earlier path to return-to-play. For this reason we will use a variety of techniques to assess and treat the acute groin injury. Assessment will not only include the painful muscle(s) and their associated tendons, but supporting myofascial structures as well as the movement of nearby joints, including the sacroiliac and coxofemoral (or “hip joint proper”) joints. While there is an ongoing debate as to whether the sacroiliac joint is capable of movement, manual therapy mobilization techniques (aka “chiropractic adjustments”) often result an athlete self-report of greater comfort. Is this report due to a placebo effect? Perhaps, but probably not. Is it rather a desensitization of pain perception at the cerebral cortex? Probably — and then some. Is there an actual increase in excursion of the ilium relative to the sacrum, or vice versa, within the sacroiliac joint itself? I don’t know. However, in “ancient” literature (Colachis, et al) there is evidence that the sacroiliac joint does, in fact, move. And other clinicians smarter than me (Cassidy, Kirkaldy-Willis, Giles) hold that the sacroiliac joint is subject to movement restrictions that are amenable to manipulation, resulting in improved movements. But I digress.
Our comprehensive evaluation includes an assessment of fascial tissues at some distance from the site of groin pain as well. Often the adductors collectively, and gracilis most predictably, contain palpable “lumpy bits” (trigger points, fascial adhesions, etc.) that are well-localized and produce a perception of intense local discomfort, often with radiation to the site of injury, or radiation distally to the knee. These lesions, whether truly within the muscles themselves or within the fascial network surrounding the muscles, can be appreciated by untrained laypeople as well as trained clinicians, and even by the athlete herself. These entities are not entirely subjective or mysterious. In fact, one researcher working with Dr. Jay Shah, MD at the National Institutes of Health, found that musculoskeletal ultrasound imaging could reveal these “lumpy bits” through the use of high frequency vibration during ultrasound examination. While the tissues surrounding the “trigger point” would respond to the vibration with a homogeneous appearance, the more dense — and painful-to-palpation — trigger point appeared as a well-demarcated zone of NON-VIBRATION (or, at least, discernibly different vibration.) These and other attempts to define these clinically observable (and treatable!) “lumpy bits” were presented at the University of Salford, Manchester, England at a conference in March of 2012. Remarkable stuff, and encouragement to me and my colleagues at our center to identify these intramuscular dysfunctions early on, treat them quickly, and restore the athlete to comfort and full competition as soon as possible.
Along these lines we also use a most gentle form dry needling, thought to enhance the local physiology of tissue repair, and certainly another way to perhaps desensitize the nervous system so that earlier functional gains can be achieved through rehabilitation.
Finally, while the investigators from Copenhagen University (see top of this post) are recommending an open chain approach to strengthening the adductors, I borrow from the wisdom of Dr. Alison Grimaldi who recently earned her PhD in the topic of lateral hip pain. Extrapolating from her work on rehabilitating acute and chronic gluteus medius tendinosis, we consider closed chain lateral/medial sliding exercises — carefully — to be a rational approach in the progression of adductor/groin strains. More from Dr. Grimaldi on a recent BJSM podcast here.
To summarize, groin strains are pretty easy to diagnose, but can be frustrating to recover from — often having a protracted course. That said, a comprehensive musculoskeletal evaluation and treatment approach is, I believe, more likely to result in a faster and more complete outcome, with earlier return to competition and greater satisfaction for the athlete. These statements are unsupported by randomized, controlled clinical trial, but like much of what we do, expert opinion and 30 years of experience may count for something. And along those lines, I’m always open for correction, for new learning, and anything that is better than I am currently doing for the benefit of my patient-athletes!