An abdominal muscle strain is more likely when localized pain follows a clear loading event and is reproduced by contracting, stretching or rotating the trunk. A hernia, a nerve entrapment, a core muscle injury near the pubic bone and problems inside the abdomen can all produce similar symptoms, so pain location and provocation should be interpreted as part of the entire examination rather than as a stand-alone diagnosis.
When pain may be coming from the abdominal wall
Chronic abdominal pain
Up to 30%
of cases are attributed to abdominal wall pain syndromes, including ACNES, myofascial pain and muscle strain
PMID 41940592
Carnett’s test
Wall vs organ
tenderness unchanged or worse with the muscles tensed points to the abdominal wall; limited value in acute pain
PMID 38340209
Carnett’s test localizes pain to the abdominal wall. It does not tell a strain from a hernia or a trapped nerve.
Screen before you localize
Abdominal pain is not automatically musculoskeletal. Fever, vomiting, blood in the stool, urine or vomit, black stools, yellowing of the skin, unexplained weight loss, a rigid abdomen, pain during pregnancy or with abnormal bleeding, testicular pain or swelling, and sudden, severe or worsening pain require medical evaluation. So does pain that is clearly related to eating, bowel habits, urination or the menstrual cycle.
A painful bulge in the groin or abdominal wall that becomes firm, tender or will not go back in needs urgent medical attention, because it can indicate a trapped hernia. Only once the presentation fits a mechanical pattern does the question become which abdominal wall structure is responsible.
Why the abdominal wall is overlooked
Abdominal wall pain syndromes, including anterior cutaneous nerve entrapment syndrome (ACNES), myofascial pain and muscle strain, account for up to 30% of chronic abdominal pain cases, yet they remain under-recognized, leading to diagnostic delays and unnecessary investigations (Thomas, 2026). A classic family-practice review made the same point: when chronic abdominal pain has little relationship to eating or bowel function but a clear relationship to posture or movement, the abdominal wall should be suspected (Suleiman, 2001).
The up-to-30% figure comes from a short case-series report and covers several different abdominal wall conditions together. It is a reason to examine the abdominal wall, not an estimate of how often muscle strain specifically is the cause.
The structures involved
- Rectus abdominis: the vertical muscle at the front of the abdomen, running from the lower ribs to the pubic bone
- External and internal obliques and transversus abdominis: the layered side wall, linking the lower ribs to the pelvis and the rectus sheath
- Rectus-adductor aponeurosis: the connective tissue at the front of the pubic bone where the rectus abdominis and adductor longus attachments blend
- The inguinal canal: the passage above the groin crease where inguinal hernias occur
- Anterior cutaneous nerves: small sensory branches that pierce the abdominal wall near the edge of the rectus abdominis
How an abdominal muscle strain behaves
Abdominal wall muscle pain typically behaves mechanically: it follows a loading event, sits in a relatively localized area and is reproduced by contracting, stretching or rotating the trunk. Typical mechanisms include sit-ups or crunches, throwing and racquet sports, golf, rowing, kicking, heavy lifting and a forceful cough or sneeze.
A rectus abdominis strain usually hurts at the front of the abdomen, often toward its lower attachment, with sit-ups, getting out of bed, trunk extension or a hard cough. An oblique or side strain hurts along the side of the abdomen or the lower rib margin with rotation and side bending. In throwing and bowling athletes, side strain typically involves the internal oblique at the lower ribs and occurs mostly on the side opposite the dominant arm (Nealon, 2017).
Professional baseball shows how specific these patterns can be. Across two decades of Major League Baseball injury data, 393 abdominal muscle strains accounted for 5% of all injuries. At least 92% involved the oblique or intercostal muscles, and 78.1% of pitcher injuries were on the side opposite the throwing arm (Conte, 2012). Those figures describe elite throwers; recreational patterns are less well studied.
How a hernia behaves
A hernia is a defect in the abdominal wall through which fat or bowel can protrude. Inguinal hernias occur above the groin crease; other abdominal wall hernias occur at the umbilicus, along the midline or at a previous incision. A hernia may produce a bulge that appears with standing, coughing or straining and disappears when lying down, and a dragging or aching discomfort that builds with activity.
The difficulty is the hernia that cannot be felt. Occult inguinal hernias are not detectable on physical examination but can often be seen on imaging, and their diagnosis can be challenging (Henderson, 2024). A person with an occult hernia may simply report groin or lower abdominal pain with coughing and lifting, which is exactly how a muscle strain presents.
Why imaging matters for suspected hernia
In a modified Delphi process, an expert panel of three surgeons and five radiologists agreed that dynamic ultrasound is a good first confirmatory imaging choice for suspected occult inguinal hernia. The panel also recommended that the ordering clinician tell the radiologist the indication, symptoms and any prior hernia surgery, and that the report state whether a hernia was assessed for, its contents and the size of the defect (Henderson, 2024).
Dynamic ultrasound matters because a hernia often appears only when abdominal pressure rises. The study is performed while the patient coughs, strains or stands. This is expert consensus rather than a diagnostic-accuracy trial, but it reflects how surgeons and radiologists approach the problem. A suspected hernia is referred for medical evaluation and imaging rather than treated as a strain.
Is it the abdominal wall? Carnett's test
Carnett's test is a simple bedside maneuver. The examiner locates the tender spot, then asks the patient to tense the abdominal muscles, typically by lifting the head and shoulders or both legs. If the tenderness stays the same or increases, the abdominal wall is the likely source; if it eases, the tensed muscles are shielding a deeper, visceral source.
A 2024 narrative review concluded that several clinical studies support Carnett's test for diagnosing chronic abdominal wall pain, that it is simple and safe, and that its diagnostic use for acute abdominal pain is limited (Sun, 2024). It is a localizing test, not a tissue diagnosis. A muscle strain, ACNES, a hernia and a rectus sheath hematoma can all produce a positive result, so a positive Carnett's test opens the next question rather than answering it.
When abdominal wall pain is nerve pain
ACNES occurs when a small cutaneous branch of a lower thoracic nerve is irritated where it passes through the abdominal wall, usually near the edge of the rectus abdominis. It typically produces a small, sharply localized painful spot, sometimes with altered or heightened skin sensation over the area. It is a common cause of chronic abdominal wall pain and is often missed.
ACNES is not a muscle strain, and it is managed differently. A 2026 scoping review of 18 studies involving 3007 patients described trigger point injection as the usual first step, serving both as a diagnostic tool and as treatment, followed by pulsed radiofrequency and surgical neurectomy for persistent pain (De Troyer, 2026). It is not treated with shockwave.
Lower abdominal pain near the groin
Pain just above the groin crease or at the pubic bone adds another set of possibilities: core muscle injury involving the rectus abdominis insertion or the rectus-adductor aponeurosis, adductor-related groin pain, pubic bone stress and hip-joint problems. In athletes, pain localized above the inguinal ligament, especially with tenderness at the rectus abdominis insertion, is highly suggestive of core muscle injury (Forlizzi, 2023). That spectrum is explained in core muscle injury and the rectus-adductor aponeurosis.
Side-by-side comparison
| Source | Typical location | Typical triggers | Helpful clues | Next step |
|---|---|---|---|---|
| Rectus abdominis strain | Front of abdomen, often lower | Sit-ups, trunk extension, coughing | Clear loading event, pain on resisted trunk flexion | Progressive trunk loading |
| Oblique or side strain | Side of abdomen, lower rib margin | Rotation, throwing, swinging | Often opposite the dominant arm in throwers | Graded rotation loading; imaging if severe |
| Inguinal or other hernia | Groin crease, umbilicus, midline or incision | Standing, straining, lifting | Bulge or dragging ache; may not be palpable | Medical referral and dynamic ultrasound |
| ACNES | Small spot, often at rectus edge | Pressure, tensing, tight clothing | Sharply localized; skin sensitivity | Nerve-focused medical pathway |
| Core muscle injury | Above the groin, at the pubic bone | Kicking, cutting, sit-ups | Tenderness at rectus insertion; adductor overlap | Exam and often MRI |
| Visceral cause | Variable, often diffuse | Eating, bowel habits, urination | Tenderness eases on Carnett's test; systemic symptoms | Medical evaluation |
These patterns overlap. A table can organize the reasoning, but it cannot replace the examination.
What the examination looks at
- A visceral, urinary, gynecologic and general health screen
- The mechanism, timing and course of the pain
- Exact pain location and focal tenderness
- Carnett's test
- Resisted trunk flexion, rotation and side bending, and coughing
- Standing and straining to look for a bulge
- Skin sensation over the painful spot
- Adductor, pubic and hip testing when pain sits near the groin
Management depends on the diagnosis
A confirmed abdominal wall muscle strain is managed with graded trunk loading: pain-free bracing and breathing, isometric work, controlled flexion, rotation and side bending, anti-rotation exercise, loaded rotation and finally sport or work tasks. Manual treatment or, in selected chronic cases, shockwave may support that progression, as reviewed in shockwave and manual therapy for abdominal wall muscle injury.
A hernia, ACNES or a visceral cause follows a different pathway entirely. None of them is treated as a strain, and none is treated with shockwave.
How Novo approaches abdominal wall pain
We screen for medical causes, localize the pain, use Carnett's test, test trunk loading, look for hernia signs, consider nerve and groin sources, and arrange imaging or referral when needed. See how we approach abdominal wall, oblique and rectus muscle pain.
References
- Thomas NC, Viswanath A, Sivalingam A, John JA, Simon EG. Abdominal wall pain syndromes: alas! The lost art of clinical diagnosis. Tropical Doctor. 2026;56(3):530-532. PMID 41940592. (link)
- Sun XX, Liu H, Qin XZ, Li MR, Yan QH, Zhang GJ. The diagnostic value of Carnett's test with chronic abdominal pain: a narrative review. Current Pain and Headache Reports. 2024;28(4):251-257. PMID 38340209. (link)
- Suleiman S, Johnston DE. The abdominal wall: an overlooked source of pain. American Family Physician. 2001;64(3):431-438. PMID 11515832.
- Henderson K, Chua S, Hasapes J, Shiralkar K, Stulberg J, Tammisetti V, et al. Recommendations for the diagnosis of occult inguinal hernias using a modified Delphi technique. Hernia. 2024;28(6):2387-2391. PMID 39325323. (link)
- De Troyer A, Allaeys M, Verelst F, Berrevoet F. Management strategies for anterior cutaneous nerve entrapment syndrome: a scoping review. Hernia. 2026;30(1):72. PMID 41543627. (link)
- Nealon AR, Kountouris A, Cook JL. Side strain in sport: a narrative review of pathomechanics, diagnosis, imaging and management for the clinician. Journal of Science and Medicine in Sport. 2017;20(3):261-266. PMID 27616432. (link)
- Conte SA, Thompson MM, Marks MA, Dines JS. Abdominal muscle strains in professional baseball: 1991-2010. American Journal of Sports Medicine. 2012;40(3):650-656. PMID 22268233. (link)
- Forlizzi JM, Ward MB, Whalen J, Wuerz TH, Gill TJ 4th. Core muscle injury: evaluation and treatment in the athlete. American Journal of Sports Medicine. 2023;51(4):1087-1095. PMID 35234538. (link)
