Abdominal Muscle Strains
Abdominal Muscle Strains
Jonathan A. Becker
Basics
Description
Injury to the abdominal wall musculature:
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Typically a noncontact injury, but may be caused by trauma
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Acute or subacute injury
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Acute injury result of an abrupt movement of the trunk
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Subacute injury caused by repetitive activity
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The abdominal wall musculature includes rectus abdominus, internal/external obliques, and transverse abdominus.
Epidemiology
Somewhat uncommon injuries, but specific sports have a higher prevalence:
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Account for <2% of athletic injuries (1)
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Sports with repetitive trunk rotation have higher rates:
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Soccer, tennis, ice hockey, gymnastics, pole vault
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Seen in runners, as the abdominal muscles are used for pelvic stabilization
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Attributed to weight training and abdominal workouts as well
Risk Factors
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Poorly conditioned abdominal musculature or deficits in core strength
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Previous abdominal wall muscle strain/tear
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Poor weight training or conditioning techniques
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Participation in activities that require abrupt and/or repetitive movements of the torso
General Prevention
Appropriate weight training and conditioning techniques with attention to core strength
Etiology
Acute or chronic muscle-tendon injury of the abdominal wall musculature
Diagnosis
History
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Acute abdominal wall pain associated with stretching or twisting mechanism
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Chronic pain due to repetitive activity of the trunk or torso
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Direct trauma associated with a minority of these injuries
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Pain usually focal and exacerbated by specific movements or positions
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Pain with active contraction of affected muscle during sneezing or coughing
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Symptoms generally subside in the absence of activity.
Physical Exam
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Appearance is typically normal with swelling and evidence of contusion rare in the absence of preceding trauma.
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Splinting may be noted if pain is severe.
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Tenderness of the abdominal wall is usually focal and discrete, but may be more diffuse in overuse type injury.
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Muscle defect may be notable if an associated tear or herniation is present.
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Peritoneal signs are absent.
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Symptoms are reproduced by contraction of the affected muscle.
Diagnostic Tests & Interpretation
Imaging
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Plain films, CT scan indicated if there is concern for rib fracture or intra-abdominal process
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MRI can be utilized to assess for muscle tear or to assess the extent of injury:
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Reserved for more severe injuries
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Musculoskeletal US may prove to be the diagnostic procedure of choice.
P.3
Differential Diagnosis
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Abdominal wall contusion
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Abdominal wall hematoma:
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Swelling, periumbilical contusion, and a mass with rigidity and/or guarding are signs of a rectus sheath hematoma
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Abdominal wall hernia (umbilical, Spigelian)
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Intra-abdominal injury (contusion, laceration, perforation)
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Intra-abdominal process (eg, infection, mass, etc.)
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Iliac apophysitis
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Osteitis pubis
Treatment
Acute treatment:
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Remove the athlete from the offending activity.
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Ice
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Compressive wrap
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NSAIDs or acetaminophen
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Once pain subsides, a rehabilitation program may be initiated (1,2)[C].
Medication
First Line
NSAIDs or acetaminophen:
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Avoid NSAIDs if there is concern for bleeding or hematoma.
Second Line
Narcotics or muscle relaxants may be utilized for more severe injuries, but are rarely needed.
Additional Treatment
General Measures
Rehabilitation:
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Assess abdominal muscle strength and core strength/stability.
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Initiate a rehab program once pain has subsided:
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Start with passive stretching.
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Advance to strengthening activities.
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Progress to sport-specific activities (1,2)[C].
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Additional Therapies
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Modalities such as US or muscle stimulation may help alleviate symptoms.
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Corticosteroid injection at the site of muscle tear/strain may be considered for acute pain relief or refractory cases.
Surgery/Other Procedures
Surgery may be necessary in cases of rectus sheath hematoma, hernia, or intra-abdominal process.
Ongoing Care
Follow-Up Recommendations
The athlete may return to activity once pain subsides and they can engage in sport-specific activity.
Prognosis
Overall prognosis for recovery is excellent:
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Duration of symptoms is variable and may persist for months.
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Recurrence rates are high (>20%).
References
1. Johnson R. Abdominal wall injuries: rectus abdominis strains, oblique strains, rectus sheath hematoma. Curr Sports Med Rep. 2006;5:99–103.
2. Maquirriain J, Ghisi JP, Kokalj AM. Rectus abdominis muscle strains in tennis players. Br J Sports Med. 2007;41:842–848.
Codes
ICD9
848.8 Other specified sites of sprains and strains
Clinical Pearls
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Athletes can return to play when there is minimal-to-no tenderness, normal muscle strength and stamina, and can perform sport-specific tasks.
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Usual duration of symptoms varies from weeks to months.