Does Percutaneous Neuromodulation Promote Recovery in Hockey Players With Grade 0 Adductor Injuries?

Ice hockey is one of the most widely followed and practiced professional sports in both North America and Europe, with a high number of registered players in both regions. The sport continues to expand globally, reaching nations in diverse parts of the world such as Africa and Australia. In North America, the National Hockey League (NHL) is the top professional league, comprising 32 teams and approximately 750 active players, supported by minor leagues like the American Hockey League (AHL) and the East Coast Hockey League (ECHL), which together include over 1,800 players. Consequently, the total number of professional players in North America exceeds 2,500 athletes. The number of adult professional and non-professional registered players in North America is approximately 230,000 (IIHF Survey). In Europe, ice hockey is structured into various top-level national championships, which collectively account for 1,500 to 2,000 professional players. The total number of adult registered players in this region is approximately 83,000. Therefore, it is estimated that the number of professional ice hockey players worldwide is around 4,000 to 4,500, confirming the strong presence and ongoing development of the sport at an international scale.

This sport requires the integration of several key elements, including physical intensity, speed, and strategy, demanding a high level of athletic preparation and close attention to injury prevention. A professional player must train specifically to develop explosive power, static and dynamic balance, and anaerobic endurance in order to accelerate rapidly, change direction with agility, and maintain puck control under pressure. Constant physical contact and the risk of high-speed collisions increase the likelihood of injuries, with frequent muscular and joint trauma, particularly in the knees and shoulders, as well as concussions caused by impacts with boards or other players. In their systematic review, Bérubé et al. aimed to determine the most common orthopedic injuries among NHL players. The most studied anatomical regions were the hip and pelvis (24%), followed by the ankle (10%), knee (10%), shoulder (7%), and foot (7%).

This sport imposes intense physical demands that generate specific biomechanical requirements, particularly on the lower limbs, often forcing the hip to perform repetitive movements beyond its physiological limits. Players are frequently affected by groin injuries or hip joint pain, which may prevent them from competing. So-called "groin pain" is a widespread issue among ice hockey players and may have an acute or chronic etiology, originating from extra-articular or intra-articular structures that produce varying symptoms. Kuhn et al. identified the most common intra-articular injuries as acetabular labrum tears, femoroacetabular impingement (FAI) - both "cam" and "pincer" types - cartilage degeneration, and intra-articular loose bodies. Among these, acetabular labrum tears had the highest incidence (69.1%), followed by cartilage injuries (13.8%), loose bodies (6.3%), and FAI (5.3%). The most frequent extra-articular conditions include adductor muscle and abdominal injuries.

Hip adduction is performed by six muscles: adductor longus, adductor magnus, adductor brevis, gracilis, obturator externus, and pectineus. All are innervated by the obturator nerve (both anterior and posterior branches), except for the adductor magnus, which also receives innervation from the sciatic nerve, and the pectineus, which also receives fibers from the femoral nerve.

From a biomechanical standpoint, skating is a biphasic movement involving single and double support phases and a swing phase. Propulsion is achieved through hip extension, abduction, and external rotation, along with knee extension. During this phase, the hip must move in flexion-extension (sagittal plane), abduction-adduction (frontal plane), and internal-external rotation (transverse plane). The adductor muscles play a key role in eccentric deceleration in the final stage of propulsion, preceding their concentric activation during leg recovery. As skating speed increases, both stride frequency and length increase, along with greater lateral hip displacement and range of motion in multiple directions. The resulting increase in hip abduction leads to greater eccentric loading on the adductors. Repeated eccentric contractions, necessary to control leg deceleration, can contribute to muscle injuries, highlighting the need for preventive strategies.