Groin Strains in Hockey: The Injury That Never Fully Heals
Ask any veteran hockey player about persistent nagging injuries, and groin pain invariably tops the list. Unlike dramatic knee injuries ending seasons with surgical urgency, or concussions forcing immediate removal from play, groin strains exist in a frustrating gray zone where players can technically continue participating despite constant discomfort, reduced performance, and the nagging awareness that the injury isn’t truly healing. This chronicity transforms what should be a manageable muscle strain into a career-altering condition—research tracking professional hockey demonstrates that groin strains account for 10-11 percent of all injuries, with recurrence rates reaching 24 percent, meaning nearly one in four players experiencing groin strains will re-injure the same region despite completing rehabilitation protocols.
The numbers reveal groin injuries as hockey’s most common soft tissue pathology. Studies tracking elite Swedish ice hockey found groin strains representing 10 percent of all injuries, while Finnish professional players reported groin strains accounting for 43 percent of all muscle strains—meaning that when hockey players tear muscles, it’s the groin nearly half the time. A single NHL team tracked over multiple seasons documented groin strain incidence of 3.2 injuries per 1,000 player-game exposures, and larger studies tracking 26 NHL teams found that adductor strain incidence actually increased from 2003-2009 despite growing awareness and prevention efforts, suggesting the injury’s biomechanical roots in skating mechanics prove difficult to overcome through conventional interventions.
The injury’s prevalence extends beyond professional hockey—research examining male field hockey players found 17 percent experiencing hip/groin pain during single seasons, with 36 percent developing symptoms over 1.5-season periods. Among elite hockey athletes across various levels, over half experience hip and groin pain during their careers, with these symptoms likely attributed to the unique biomechanical demands of skating creating extraordinary stress on hip and groin structures. The high prevalence, combined with frustrating recurrence rates and tendency toward chronicity, makes groin injuries arguably hockey’s most problematic soft tissue pathology despite receiving far less attention than more dramatic injuries like concussions or knee ligament tears.
The biomechanical mechanism explains why hockey creates such extraordinary adductor vulnerability. Skating involves powerful hip extension and abduction generating forward propulsion—the gluteals and hip abductors serve as primary movers driving each stride. Simultaneously, the hip adductors must work eccentrically (lengthening while contracting) stabilizing the hip and decelerating the leg during each stride cycle, preventing excessive abduction that would create inefficient energy-wasting leg motion. This creates a muscular imbalance scenario where powerful agonist muscles (abductors/extensors generating propulsion) overpower relatively weaker antagonist muscles (adductors providing eccentric control), setting the stage for adductor strain when demands exceed capacity.
Approximately 90 percent of hockey groin injuries occur through non-contact mechanisms rather than traumatic collisions, suggesting that the repetitive biomechanical loading inherent to skating—not external trauma—represents the primary injury pathway. Players don’t tear adductors from taking checks or colliding with opponents; instead, the muscles gradually accumulate microtrauma from thousands of skating strides eventually exceeding tissue tolerance and creating symptomatic strains. Understanding why skating creates such unique adductor vulnerability, recognizing the subtle warning signs before progression to complete tears, implementing evidence-based prevention strategies emphasizing eccentric adductor strengthening, and managing the complex rehabilitation ensuring complete recovery rather than chronic dysfunction proves essential for protecting hockey players throughout their careers.
The Biomechanics of Skating: Setting Up Adductor Failure
Understanding the Skating Stride Cycle
The forward skating stride involves complex coordinated movements creating propulsion through powerful unilateral hip and knee extension combined with hip abduction. Breaking down the stride cycle reveals specific phases creating adductor vulnerability:
Glide phase: One leg remains extended behind the body supporting body weight while gliding on the ice blade. During this phase, minimal active muscular contraction occurs—the skater rides momentum from the previous propulsive stroke while preparing the opposite leg for its propulsive phase.
Recovery phase: The previously extended leg flexes at hip and knee, adducting (moving toward midline) to position beneath the body’s center of mass preparing for the next propulsive stroke. During recovery, the hip adductors contract concentrically bringing the leg inward, though forces remain relatively modest since the leg moves through air (or just above ice) rather than generating propulsion against resistance.
Propulsive phase: This represents the critical moment for adductor loading. The recovered leg extends powerfully at hip and knee while simultaneously abducting (moving away from midline), driving the skate blade laterally against the ice generating propulsive force. The hip extensors (gluteus maximus, hamstrings) and hip abductors (gluteus medius, tensor fasciae latae) serve as primary movers creating this explosive extension-abduction movement. However, uncontrolled abduction would waste energy directing force laterally rather than forward—the hip adductors must contract eccentrically resisting excessive abduction, controlling the leg’s lateral motion, and stabilizing the hip throughout the powerful extension stroke.
This eccentric adductor contraction during propulsion creates extraordinary muscle loading. The adductors lengthen while simultaneously generating tension attempting to decelerate the rapidly abducting leg driven by powerful hip extensors and abductors. Eccentric muscle contractions generate higher absolute forces than concentric contractions, and muscles prove more vulnerable to injury during eccentric loading compared to concentric work. The combination—very high eccentric forces repeated thousands of times per game or practice—creates cumulative microtrauma within adductor muscle fibers and musculotendinous junctions eventually exceeding healing capacity and producing symptomatic strains.
The Adductor Anatomy Under Siege
The hip adductor muscle group comprises five muscles attaching from the pelvis to the femur, all functioning to adduct (bring together) the thighs: adductor longus, adductor brevis, adductor magnus, gracilis, and pectineus. Among these, adductor longus represents the most frequently injured in hockey players, accounting for the majority of adductor strains. This muscle originates from the pubic bone and inserts on the linea aspera of the femur (a ridge running down the back of the thighbone), creating a relatively long muscle belly vulnerable to strain particularly at the musculotendinous junction where contractile muscle tissue transitions to tendinous tissue.
The adductor magnus—the largest and strongest adductor—also sustains frequent injury though somewhat less commonly than adductor longus. Adductor magnus demonstrates interesting functional duality: its anterior fibers primarily adduct the hip, while its posterior fibers also contribute to hip extension, meaning this muscle assists both stabilization (adduction) and propulsion (extension) during skating. This dual role creates substantial loading during the propulsive phase potentially contributing to injury susceptibility.
Beyond the adductor muscles themselves, the pubic symphysis—the fibrocartilaginous joint connecting left and right pubic bones at the front of the pelvis—experiences substantial shear stress during skating. Asymmetric forces from alternating left-right propulsive strokes create repetitive shearing across this joint. Chronic inflammation at the pubic symphysis, termed “osteitis pubis,” represents another common cause of groin pain in hockey players, sometimes occurring concurrently with adductor strains or independently as a separate pathology.
The Muscular Imbalance Problem
Research consistently identifies muscular imbalance between hip adductors and hip abductors as a primary risk factor for groin injury in hockey. The skating biomechanics naturally create this imbalance—the gluteus medius and other hip abductors receive massive training stimulus through serving as primary movers during every skating stride, developing substantial strength and hypertrophy. Meanwhile, the adductors work primarily in a stabilizing eccentric role receiving less hypertrophic stimulus, potentially creating strength discrepancies between these opposing muscle groups.
Studies measuring adductor-to-abductor strength ratios demonstrate that hockey players with lower ratios (relatively weak adductors compared to abductors) face elevated groin injury risk. One proposed mechanism suggests that when powerful abductors overwhelm weaker adductors during the propulsive phase, the adductors cannot adequately control the leg’s lateral motion, experiencing excessive lengthening strain potentially exceeding tissue tolerance. Alternatively, or additionally, weak adductors might fatigue more rapidly during games or practices, losing their protective eccentric control capacity later in play when cumulative fatigue peaks, creating injury vulnerability during the final periods of games.
Positional and Postural Patterns
The skating posture—characterized by forward trunk lean, hip and knee flexion, and externally rotated “turned out” hip positioning—creates chronic postural adaptations affecting pelvic and hip mechanics. This sustained posture during hundreds of hours of skating can create what biomechanics experts term “lower crossed syndrome”: tight hip flexors (from chronic hip flexion positioning) and tight lumbar erectors (from forward trunk lean maintaining extended lumbar spine) combine with weak gluteals and weak anterior core musculature.
These postural adaptations create anterior pelvic tilt—the pelvis rotates forward, creating increased lumbar lordosis (sway back). Anterior pelvic tilt lengthens the hamstrings and adductor magnus (both attach to the ischial tuberosity affected by pelvic rotation), placing these muscles at disadvantaged resting lengths potentially contributing to injury susceptibility. Additionally, the externally rotated hip positioning during skating chronically loads the external rotators and abductors while lengthening internal rotators and adductors, potentially contributing to the muscular imbalances described above.
Risk Factors: Who Gets Groin Strains and Why
Previous Groin Injury: The Strongest Predictor
History of previous groin injury represents the single most powerful risk factor for subsequent adductor strain across multiple studies. Research tracking professional soccer (which shares similar groin injury patterns with hockey) found that previous groin strain created an odds ratio of 7.3 for subsequent injury—meaning athletes with prior strains faced over seven times higher risk compared to those without injury history. Hockey-specific data confirms this pattern, with studies documenting 32-44 percent recurrence rates for groin strains.
The mechanisms underlying high recurrence involve incomplete initial rehabilitation leaving residual weakness, flexibility restrictions, or neuromuscular control deficits. Scar tissue formation within previously torn muscle fibers creates regions of altered mechanical properties—scar tissue demonstrates reduced elasticity compared to healthy muscle, potentially creating stress concentration at scar-healthy muscle interfaces during subsequent loading. Persistent strength deficits, even subtle asymmetries between injured and uninjured sides, compromise the muscle’s capacity to tolerate eccentric forces during skating. Athletes who return to play based on symptom resolution rather than objective functional criteria often retain these deficits predisposing toward re-injury.
Preseason Risk Factors
Research identifies preseason periods as particularly high-risk windows for groin injury development. The transition from off-season to competitive skating creates sudden increases in skating volume and intensity before athletes’ musculoskeletal systems fully adapt to these demands. Studies tracking NHL players found that rookies entering the league demonstrated lower groin injury rates compared to veterans, suggesting that players new to professional hockey might train more conservatively or receive greater injury prevention attention compared to established players assumed to be adequately conditioned.
Interestingly, players who practiced during off-seasons demonstrated lower injury rates than those who took complete breaks, suggesting that maintaining some skating activity during off-season periods preserves neuromuscular adaptations and tissue conditioning reducing injury vulnerability when competitive training resumes. Complete detraining followed by rapid return to full skating loads creates the “too much, too soon” scenario overwhelming tissue capacity.
Hip Range of Motion and Flexibility
Research examining soccer players found that decreased hip abduction range of motion represented an independent risk factor for groin injury, with each degree of restricted abduction creating small increments in injury risk. While hockey-specific data examining ROM patterns remains limited, the biomechanical rationale suggests that restricted hip mobility could force compensatory movement patterns creating altered loading on adductor muscles potentially contributing to injury.
However, the flexibility-injury relationship proves complex and controversial. Some researchers propose that adductor strains result from muscles being “too short and lacking flexibility,” suggesting that stretching programs would prevent injuries. Yet evidence supporting static stretching for groin injury prevention remains weak—studies implementing flexibility programs without concurrent strengthening show minimal protective effects. This suggests that while adequate flexibility might prove necessary, it’s insufficient alone without addressing the strength and eccentric capacity deficits underlying most adductor strains.
Strength Deficits and Imbalances
Low eccentric hip adduction strength represents a well-established risk factor for adductor injury in field-based sports including hockey. Research demonstrates that athletes with reduced eccentric adductor strength face substantially elevated injury risk compared to those with adequate strength. The mechanism directly relates to skating biomechanics—weak adductors cannot generate sufficient eccentric force controlling leg abduction during propulsive phases, experiencing excessive strain potentially exceeding tissue tolerance.
Beyond absolute adductor strength, the ratio between eccentric adductor strength and hip abductor strength influences injury risk. Athletes with imbalanced ratios (strong abductors relative to weak adductors) demonstrate higher injury rates than those with more balanced strength profiles. Proposed mechanisms suggest that powerful abductors create propulsive forces that weak adductors cannot adequately control, overwhelming the adductors’ eccentric capacity during skating strides.
Cumulative Load and Fatigue
While less extensively researched than strength and previous injury factors, cumulative skating load likely contributes to groin injury risk through creating progressive fatigue reducing neuromuscular control and tissue resilience. Games and practices occurring on consecutive days without adequate recovery potentially create cumulative microtrauma within adductor tissues. Late-season injury clusters might reflect accumulated fatigue from months of competitive play, though research specifically examining this pattern in hockey remains limited.
Clinical Presentation: Recognizing Adductor Strains
Symptoms and Pain Patterns
Adductor strains create characteristic symptom patterns helping clinicians distinguish them from other groin pathologies:
Pain location: Groin pain typically localizes to the inner thigh proximal region near the pubic bone where adductor muscles originate. Some athletes describe pain more distally along the adductor muscle belly or musculotendinous junction. The pain usually proves unilateral (one-sided) corresponding to the injured adductor, though bilateral symptoms sometimes occur in athletes with chronic overuse affecting both sides.
Activity patterns: Pain characteristically worsens during skating, particularly during powerful acceleration or directional changes requiring maximum propulsive force and eccentric adductor control. Some players report that specific movements create worst pain—crossovers, tight turns, or explosive starts from stationary positions all stress adductors substantially. Pain might begin only during high-intensity skating initially, progressively occurring earlier and with less provocation as injury severity worsens. Chronic cases create constant low-grade discomfort even at rest or during daily activities like walking, climbing stairs, or getting in and out of cars.
Acute versus chronic presentations: Acute adductor strains sometimes create sudden sharp pain during specific moments—a player feels something “pull” or “pop” during a hard skating stride, immediately experiencing pain limiting continued play. However, many hockey groin injuries develop insidiously without identifiable acute injury moments. Players report gradually increasing groin discomfort over days or weeks, initially mild and ignorable, progressively worsening until it limits performance or creates constant symptoms.
Physical Examination Findings
Palpation: Direct tenderness over the adductor muscle belly, musculotendinous junction, or pubic insertion helps localize injury. Palpable defects suggest complete muscle rupture though these occur rarely—most adductor strains involve partial muscle fiber tearing without complete disruption. Swelling or bruising might develop in moderate-to-severe acute strains though subtle chronic strains often demonstrate minimal visible changes.
Strength testing: Resisted hip adduction (squeezing legs together against resistance) reproduces pain and demonstrates weakness compared to the uninjured side. Testing in multiple hip positions (extended, flexed, various degrees of abduction) sometimes identifies specific positions creating maximum symptoms corresponding to injury location within the adductor muscle length. The squeeze test—performed lying supine with hips and knees bent to 45 degrees, squeezing a dynamometer or examiner’s fist between knees—provides standardized assessment quantifying adductor strength bilaterally allowing objective comparison between sides.
Flexibility assessment: Passive hip abduction (pulling legs apart) with knee extended stretches the adductor muscles, creating pain if strains exist. Restricted range of motion compared to uninjured side suggests muscular guarding or structural tissue shortening from chronic injury.
Functional tests: Single-leg balance, lateral hops, skating-specific movements all assess functional capacity. Unable to perform these tests pain-free indicates significant functional limitation requiring rehabilitation before return to play.
Differential Diagnosis
Not all groin pain represents adductor muscle strains—several other pathologies create similar symptom patterns requiring differentiation:
Athletic pubalgia (sports hernia): Despite the misnomer “hernia,” this condition doesn’t involve actual hernia with organ protrusion. Instead, athletic pubalgia represents chronic injury to the inguinal region soft tissues from repetitive stress, creating anterior groin/lower abdominal pain often radiating into upper thigh or testicles. Physical examination demonstrates tenderness over the pubic tubercle and pain with resisted sit-ups or hip flexion, distinguishing it from lateral groin pain typical of adductor strains.
Osteitis pubis: Inflammation of the pubic symphysis creates deep central groin pain sometimes radiating bilaterally. The pain worsens with activities stressing the pubic symphysis like kicking, running, or jumping. MRI or bone scan demonstrates characteristic bone marrow edema surrounding the pubic symphysis confirming diagnosis.
Hip labral tears: Intra-articular hip pathology including labral tears creates anterior or lateral hip pain sometimes extending into the groin. These injuries create mechanical symptoms (clicking, catching, locking) during hip motion and demonstrate positive impingement testing on physical examination. Hockey players face elevated hip labral tear risk from the repetitive hip flexion and rotation during skating creating cumulative shear stress on the labrum.
Iliopsoas strain: The hip flexor muscles create anterior groin pain worsening with resisted hip flexion or passive hip extension. Tenderness localizes more anteriorly than adductor strains, helping distinguish these pathologies.
Imaging and Diagnosis
Most adductor strains receive clinical diagnosis based on history and physical examination without requiring imaging. However, imaging proves valuable when diagnosis remains uncertain, when symptoms don’t respond to conservative treatment, or when ruling out other pathologies:
MRI: Provides detailed soft tissue visualization demonstrating muscle fiber disruption extent (partial versus complete tear), location within muscle (myotendinous junction most common), fluid collections or hematomas, and associated pathology. MRI also identifies other groin pathologies like labral tears, osteitis pubis, or athletic pubalgia if clinical presentation suggests these diagnoses.
Ultrasound: Dynamic ultrasound allows real-time muscle visualization during contraction, potentially identifying subtle tears or scar tissue, though operator-dependent nature limits universal applicability compared to MRI.
X-rays: Don’t visualize muscle tissue but can identify bony pathology like avulsion fractures (where muscle forcefully tears bone fragment off insertion site) or chronic stress changes at the pubic symphysis in osteitis pubis cases.
Evidence-Based Prevention: The Copenhagen Exercise Revolution
The Copenhagen Adductor Exercise
The Copenhagen Adductor Exercise represents the most extensively researched and consistently effective groin injury prevention intervention. The exercise involves lying sideways with the top leg elevated supported by a partner or bench, then lifting and lowering the body using the elevated leg’s adductor muscles, creating maximal eccentric adductor loading during the controlled lowering phase.
Basic execution: Lie on your side perpendicular to a bench or partner’s shoulder (if partner-assisted). Place top leg’s ankle/lower shin on the bench/partner. Keep bottom leg extended hovering just above ground. Contract top leg’s adductors lifting your entire body off the ground creating a straight line from shoulders to bottom foot. Hold briefly at top position, then slowly lower body over 3-5 seconds maintaining controlled descent—this eccentric lowering represents the critical strengthening component. Repeat for prescribed repetitions.
Progression levels: Multiple variations allow progressive difficulty increases accommodating different strength levels:
- Beginner: Short lever variations with knee bent and support at mid-thigh or knee rather than ankle, reducing lever arm and overall difficulty
- Intermediate: Support at ankle with straight leg, performing partial range-of-motion lifts (bottom leg touching ground between repetitions providing support)
- Advanced: Full range-of-motion with straight leg suspended throughout set, no ground contact between repetitions
- Elite: Adding resistance through weighted vests or resistance bands increasing load beyond body weight
Dosing protocols: Research examining optimal Copenhagen programming suggests starting conservatively with 2 sets of 5-6 repetitions performed 1-2 times weekly, progressing toward 3 sets of 12-15 repetitions 2-3 times weekly over 6-8 week periods. The eccentric emphasis proves critical—athletes should focus on slow controlled lowering rather than explosive lifting.
The Evidence Supporting Copenhagen
Research tracking soccer teams implementing Copenhagen exercises demonstrates remarkable protective effects. A study randomizing teams into intervention groups performing Copenhagen-based adductor strengthening versus control groups training normally found that the intervention reduced groin injury prevalence by 41 percent—a massive protective benefit from a simple exercise requiring no special equipment. Even studies showing statistically non-significant results demonstrated clinically relevant injury reductions up to 31 percent, with poor compliance explaining failure to reach statistical significance. When Copenhagen exercises are performed with high compliance (athletes actually completing prescribed sessions rather than sporadically performing exercises), injury rates decrease significantly.
The mechanism involves substantially increasing eccentric hip adduction strength—the exact capacity required to control the leg during skating propulsion phases. Studies demonstrate that Copenhagen training produces large eccentric adduction strength gains, increases the ratio between eccentric hip adduction and hip abduction strength (improving the muscular balance discussed earlier), and generates EMG activity levels sufficient to create muscle strengthening adaptations. These physiological changes directly address the biomechanical risk factors underlying most adductor strains.
Implementation Challenges and Compliance
Despite strong evidence supporting Copenhagen exercises, implementation faces practical challenges. The exercise requires substantial strength even at beginner levels—many athletes cannot perform even modified versions initially, requiring preliminary strengthening through simpler adduction exercises before progressing to Copenhagen variations. The exercise also creates significant muscle soreness particularly when first introduced, potentially reducing compliance if athletes view the discomfort as problematic rather than normal adaptation.
Compliance represents the critical factor determining prevention success. Studies with poor compliance (athletes skipping sessions or performing exercises inconsistently) show minimal injury reduction despite using effective protocols, while high-compliance studies demonstrate substantial protective benefits. This suggests that prevention programs must address compliance barriers through education (explaining the exercise’s purpose and evidence base), progressive programming (starting easy enough that all athletes can succeed, gradually increasing difficulty as capacity improves), and accountability (tracking completion, providing feedback, integrating exercises into team training rather than expecting individual adherence).
Comprehensive Prevention and Treatment
Prevention Beyond Copenhagen
While Copenhagen exercises represent the cornerstone evidence-based intervention, comprehensive prevention addresses multiple risk factors:
Adductor-abductor strength balance: Beyond Copenhagen exercises specifically, general programs ensuring adequate adductor strength relative to abductors prove important. Resistance training using cable machines, resistance bands, or specialized adduction machines develops baseline strength. Assessment of strength ratios (adduction-to-abduction strength) identifies athletes with significant imbalances requiring targeted intervention.
Hip mobility maintenance: Ensuring adequate hip range of motion through dynamic warm-ups and post-training stretching maintains flexibility allowing optimal movement patterns. However, mobility work should complement rather than replace strength training—stretching alone doesn’t prevent adductor strains.
Core and lumbopelvic control: Addressing the lower crossed syndrome common in hockey players through hip flexor stretching, anterior core strengthening, and gluteal activation helps optimize pelvic positioning reducing excessive stress on adductors.
Preseason conditioning: Gradually increasing skating volume during preseason rather than immediately resuming full training loads allows tissue adaptation preventing the sudden overload creating early-season injuries.
Off-season maintenance: Maintaining some skating activity or lower-limb resistance training during off-season prevents complete detraining that creates injury vulnerability when competitive training resumes.
Acute Injury Management
RICE protocol: Rest from aggravating activities (though not complete immobilization), ice application 15-20 minutes several times daily, compression through elastic wraps or compression shorts, and elevation reduce acute inflammation and pain.
Activity modification: Temporary reduction in skating volume and intensity allows initial healing. Cross-training through cycling or swimming maintains cardiovascular fitness while reducing adductor stress.
Progressive rehabilitation: Pain-free range-of-motion exercises maintain mobility during acute phases. Gradual strengthening begins with isometric adduction exercises (contracting without motion), progressing toward concentric strengthening, then eccentric loading (the last to return given its high stress levels). Functional exercises reintroduce skating-specific movements progressively.
Return-to-play criteria: Objective standards should guide return timing rather than arbitrary timeframes or symptom resolution alone. Criteria include pain-free full hip range-of-motion, adductor strength within 10 percent of uninjured side (measured through squeeze testing or dynamometry), successful completion of sport-specific functional tests (skating drills, direction changes, acceleration without pain), and appropriate confidence and psychological readiness.
Managing Chronic Groin Pain
Chronic adductor strains or groin pain persisting beyond 6-12 weeks despite appropriate conservative treatment require comprehensive evaluation ruling out alternative pathologies and addressing perpetuating factors:
Biomechanical assessment: Video analysis of skating mechanics identifies technical flaws creating excessive adductor stress. Altered stroke patterns, inadequate hip extension, or poor core control all potentially contribute to chronic loading.
Comprehensive rehabilitation: Addressing not just the adductors but the entire lumbopelvic complex—hip flexors, core, gluteals, hamstrings—ensures optimal mechanics reducing compensatory loading patterns.
Advanced interventions: Prolotherapy, platelet-rich plasma injections, or other regenerative medicine approaches sometimes provide benefit in refractory cases, though evidence remains limited. Surgical intervention (adductor release, pubic symphysis debridement) represents last resort after exhausting conservative options, with outcomes variable and recovery extensive.
Explore Sports Injury Gear