A core muscle injury is a tear or strain in the soft tissues where your abdominal muscles and inner thigh muscles attach to the pubic bone. It causes chronic groin pain, most often in athletes who do a lot of sprinting, cutting, or kicking. You may also see it called athletic pubalgia or a “sports hernia,” though it isn’t actually a hernia at all.
Which Muscles Are Involved
The injury centers on a small, high-stress area of the pelvis where two powerful muscle groups converge. The oblique muscles of the lower abdomen and the rectus abdominis (your “six-pack” muscle) attach to the top of the pubic bone, while the adductor muscles of the inner thigh attach to the underside. These two groups pull in opposite directions every time you twist, sprint, or kick, and the pubic bone sits right in the middle absorbing that force.
The tendons connecting the obliques to the pubic bone are especially vulnerable. In many cases, the adductor tendons on the thigh side are also stretched or torn. The injury can affect one side or both, and may involve damage to a single tendon or several structures at once.
How the Injury Happens
Core muscle injuries are driven by repetitive, high-force movements rather than a single collision. Kicking a ball, changing direction at full speed, and explosive acceleration all create enormous shearing force across the pubic bone. Over time, or sometimes in one bad moment, the tensile force stretches the muscle fibers beyond their limit and causes a tear near where the muscle meets the tendon.
Soccer and futsal players account for the vast majority of cases. In one surgical study spanning nearly two decades, over 75% of the athletes treated were professional soccer players. But the injury also shows up in hockey, football, rugby, and any sport that demands repeated sprints and lateral cuts. It’s far more common in men than women.
What It Feels Like
The hallmark symptom is pain deep in the groin, typically on one side, that gets worse with activity and improves with rest. You’ll usually feel it just above the crease of your groin, near where the lower abdominal muscles meet the pubic bone. Tenderness right at the point where the rectus abdominis inserts into the pubic bone is a strong indicator.
The pain often starts gradually. You might notice it only during intense activity at first, then find it creeping into everyday movements like getting out of a car or coughing. Some people recall a specific moment when they felt a pop or a sudden sharp pain, but many describe a slow build over weeks. Unlike a traditional hernia, there’s no visible bulge or lump in the groin.
Core Muscle Injury vs. Inguinal Hernia
The name “sports hernia” creates real confusion, because a core muscle injury is not a hernia. In a true inguinal hernia, a loop of intestine or fatty tissue pushes through a hole in the abdominal wall, creating a noticeable lump you can often see or feel. That hole won’t heal on its own. A core muscle injury, by contrast, is a strain or tear in the muscle and tendon tissue itself, with no protrusion and no palpable lump.
The symptoms overlap enough to make it tricky. Both can cause a dull ache, burning pain, or heaviness in the groin. The key differences: a strain typically has a more identifiable onset tied to athletic activity and tends to improve somewhat with rest, while a hernia may come and go but persists because the structural defect remains. Imaging and a careful physical exam are usually needed to tell them apart.
How It’s Diagnosed
Diagnosis requires a combination of physical examination and imaging, because no single test is definitive on its own. During a physical exam, a clinician will typically check for pain during a cross-body sit-up performed in a figure-of-four position, pain during a straight-leg sit-up, pain with resisted hip flexion, and the presence of tightness in the adductor muscles. The cross-body sit-up test and adductor tightness both have 100% sensitivity, meaning they’ll catch nearly every case, but they also flag other conditions. That’s why imaging is important for confirmation.
MRI is the primary imaging tool. The three most common findings on an MRI are swelling in the bone marrow at the pubic symphysis, damage to the adductor tendon, and damage to the rectus abdominis attachment. One notable finding from a systematic review: patients whose MRI showed damage to the adductor tendon attachment had significantly longer symptom duration (averaging about 23 weeks) compared to those without that finding (about 6 weeks). There’s no single universally agreed-upon MRI definition for the injury, so clinicians interpret imaging alongside the full clinical picture.
Non-Surgical Treatment
The first line of treatment is always conservative, typically for a minimum of three to six months before surgery is considered. This involves rest and scaling back from the activities that trigger pain, anti-inflammatory medication, and a structured physical therapy program.
Physical therapy for a core muscle injury follows a specific progression. The early phase focuses on controlling pain and swelling. From there, the program builds coordination and strength in the hip adductors, hip flexors, core stabilizers, and the muscles surrounding the lower spine and pelvis. The deeper goal isn’t just strengthening individual muscles but retraining how those muscles fire together during functional movements like running, cutting, and kicking. Injections (corticosteroid or platelet-rich plasma) are sometimes used alongside therapy to manage pain and inflammation during recovery.
For many athletes, this approach works. But when several months of dedicated rehab don’t resolve the pain, surgery becomes the next option.
When Surgery Is Needed
Surgery is reserved for cases where conservative treatment hasn’t provided enough relief. The most common procedures involve releasing tension at one or both of the key attachment points on the pubic bone. One well-studied technique releases the front portion of the rectus abdominis tendon at the pubic symphysis and cuts the adductor longus tendon where it connects to the pubic bone, relieving the competing forces that caused the injury.
Results from this approach are encouraging. In a study of 45 male athletes (mostly professional soccer players), the symptom resolution rate was 93.3%, with a complication rate of just 6.7%. The average time to return to sport after surgery was 135 days, roughly four and a half months. Athletes with injuries on only one side tended to return faster than those with bilateral involvement.
What Recovery Looks Like
Whether you go the conservative or surgical route, returning to sport is a gradual process. With physical therapy alone, the minimum timeline is three to six months of dedicated rehab before you can reasonably judge whether it’s working. Some athletes respond well within that window, especially if the injury is caught early and involves less structural damage.
After surgery, expect about four to five months before returning to full competition. The post-surgical rehab process mirrors the conservative approach in many ways: early pain management, then progressive strengthening, then sport-specific movement retraining. Rushing the timeline increases the risk of re-injury, particularly because the underlying biomechanical demands that caused the problem in the first place (kicking, sprinting, cutting) will still be part of your sport. A full return means not just being pain-free but having rebuilt the strength and coordination to handle those forces safely.