What causes groin injuries in soccer?

Groin strains in soccer are adductor muscle injuries — the muscles on the inner thigh that pull the leg toward the midline. They're caused by rapid direction changes, kicking across the body, and high-speed sprinting with lateral components. The adductors are eccentrically loaded (lengthening under force) during these movements, and when they lack sufficient eccentric strength, the tissue tears. Poor pre-season conditioning and sudden increases in training load are the most common contexts for groin injuries.

What is the Copenhagen plank and does it really work?

The Copenhagen plank (also called the Copenhagen hip adduction exercise) is a side plank variation where the top leg is supported on a bench or box. The bottom leg lifts and lowers, working the hip adductors eccentrically. A landmark BJSM study in Danish elite soccer showed a 41% reduction in adductor injury rates in players who followed a Copenhagen plank protocol. It's now the most evidence-supported groin injury prevention exercise available.

How is a groin strain different from a sports hernia?

A groin strain is a muscle injury to the adductors — it hurts at the inner thigh, typically worsens immediately with kicking or direction changes, and improves with rest. A sports hernia (athletic pubalgia) is a tear or weakness in the posterior inguinal wall, causing deep groin or lower abdominal pain that worsens with exertion. Sports hernias require imaging and often surgical repair. If groin pain doesn't improve within 2–3 weeks of rest and load modification, see a sports medicine doctor to rule out a sports hernia.

How long does a groin strain take to heal in youth soccer?

Grade 1 (mild) adductor strains typically resolve in 1–3 weeks with modified training. Grade 2 (moderate — partial tear) takes 4–8 weeks. Grade 3 (complete tear) is rare in youth players but can require 3–6 months. The most important predictor of recovery time is whether the player returns to training before the adductor has regained full strength — premature return increases recurrence risk to 30%+.

Prevent Groin Injuries in Soccer: Adductor Strengthening That Actually Works

Every time a soccer player cuts sharply to one side, the adductors on the planted leg must rapidly decelerate and redirect the body's momentum. Do this a hundred times a match, over a full season, without building the adductors' eccentric capacity to handle that load — and eventually, they tear.

Groin strains are the second most common muscle injury in soccer globally. They're also frequently mismanaged — players return too early, the adductor re-tears, and what could have been a 2-week setback becomes a chronic problem that haunts the rest of the season.

Why Soccer Players Get Groin Injuries

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High-speed cutting and direction changes: Every plant-and-cut demands that the adductors eccentrically absorb and redirect body momentum. At full speed, this is an extreme eccentric load.

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Kicking across the body: Crossing passes and shots across the body put the adductor on stretch while also demanding it generate force — the highest-risk combination.

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Sudden pre-season load increases: The most common timing for groin injuries is pre-season — players jump from low-activity summer to full training load in 1–2 weeks. Unprepared adductors fail under the rapid increase.

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Adductor-to-abductor strength imbalance: Players with stronger abductors (hip abductors) than adductors (hip adductors) are at significantly higher groin injury risk. The imbalance creates instability during cutting.

The Prevention Program

The Copenhagen plank is the headline, but a complete groin injury prevention program includes eccentric loading across multiple movement patterns. All five exercises below target the adductors in different positions and loading angles — because groin injuries occur across multiple soccer movement patterns, not just one.

Copenhagen Plank (Hip Adduction)

Week 1: 3 × 5 each side. Build to 3 × 12 over 8 weeks.

Side plank with the top leg elevated on a bench at knee/thigh height. Raise and lower the bottom leg slowly. The adductor of the top leg is doing the eccentric work. Keep the torso in a straight line. Do NOT rush reps — the eccentric control is the point.

Progression: Start with top foot on a low bench. Progress to full version with top thigh on bench.

Evidence: 41% reduction in adductor injuries (BJSM, Danish elite soccer RCT)

Sumo Squat (Wide Stance)

3 × 10

Feet wider than shoulder-width, toes turned out at 45°. Squat to depth, pushing the knees out over the toes throughout. The adductors control the descent and generate force on the ascent. Keep the torso upright.

Progression: Bodyweight → goblet squat with weight → barbell sumo

Evidence: Builds adductor strength through hip-flexion range — complementary to the plank work

Lateral Lunge

3 × 8 each side

Step wide to one side, sit into that hip until the thigh is parallel to the ground. Push back up through the stepped leg. The adductor of the working leg eccentrically controls the lateral descent — exactly the movement pattern of a wide cut in soccer.

Progression: Bodyweight → holding a dumbbell at chest

Evidence: Trains adductors in the transverse and frontal plane — the planes where groin injuries occur

Isometric Ball Squeeze

3 × 30-second holds

Lying on your back, knees bent. Place a medicine ball or firm pillow between the knees. Squeeze and hold for 30 seconds at 60–70% effort — not a maximum clench. Best used as an entry point after groin injury before progressing to Copenhagen planks.

Progression: Rehabilitation entry point before eccentric loading

Evidence: Isometric adductor loading at 60–70% is pain-free and builds tolerance before eccentric training

Band Hip Adduction (Standing)

3 × 12 each leg

Band around the ankle, attached to a fixed point to the side. Standing on the other leg, adduct (pull) the banded leg across the midline in a slow, controlled arc. Return under control. Trains adductors in a standing, sport-specific position.

Progression: Light band → heavier band

Evidence: Functional adductor strengthening in the position most used during soccer movement

Weekly Schedule

Phase	Frequency	Priority Exercises
Pre-season (4–6 weeks)	3× per week	Copenhagen plank + sumo squat + lateral lunge. Build volume across weeks.
Early in-season	2× per week	Copenhagen plank + lateral lunge. Maintain the pre-season base.
Mid/late in-season	1–2× per week	Copenhagen plank maintenance dose (2 × 8). Don't drop it entirely.
Post-injury re-entry	Progress through ball squeeze → band adduction → Copenhagen	Pain-free isometric first, then eccentric progression with physiotherapy guidance

The return-to-sport benchmark

After a groin strain, don't return to full training based on pain reduction alone. The adductor needs to be within 10–15% of the uninjured side on a strength test (or a simple Copenhagen plank endurance comparison) before the player resumes cutting and kicking at full intensity. Premature return based on feeling OK is the leading cause of re-injury.