What is strained when experiencing pain down the anterior groin through the medial thigh after walking?

Anterior Groin and Medial Thigh Pain After Walking: Adductor Muscle Strain

The most likely diagnosis is an adductor muscle strain, specifically involving the adductor longus, which is the most commonly injured muscle in this anatomic distribution and clinical presentation. 1, 2

Clinical Presentation and Anatomy

The adductor muscle group is responsible for keeping the legs pressed together and is frequently strained during activities involving acceleration, repetitive movements, and pivoting. 1 The characteristic pain pattern you describe—anterior groin radiating through the medial thigh—is classic for adductor-related groin pain. 1

• Pain location: The adductor longus originates at the pubic bone and inserts along the medial femur, explaining the distribution from groin to medial thigh 3, 2
• Aggravating factors: Walking, kicking, and functional activities that require adduction or hip flexion typically worsen symptoms 4, 2
• Sports medicine context: Adductor strains represent approximately 68% of all groin injuries in athletes, though they occur in recreational activities as well 4

Differential Diagnosis Considerations

While adductor strain is most likely, you must exclude other causes of anterior groin and medial thigh pain:

Obturator Nerve Entrapment

• Clinical pattern: Exercise-induced medial thigh pain starting at the adductor origin and radiating distally 5, 6
• Key distinguishing features: Paresthesias in the medial thigh cutaneous distribution, adductor muscle weakness, and denervation on needle electromyography 5, 6
• When to suspect: If pain persists despite conservative management or if neurologic symptoms (numbness, weakness) are prominent 5

Hip-Related Pain (FAI Syndrome)

• Primary symptom: Groin pain is the hallmark, though pain may radiate to the back, buttock, or thigh 1
• Key distinction: Hip-related pain is typically motion-related and associated with specific hip examination findings 1
• Clinical pearl: Absence of groin pain helps exclude FAI syndrome and labral pathology 1

Vascular Claudication (Less Likely Given Age/Context)

• Pattern: Pain with walking that resolves within 10 minutes of rest in any position 7, 8
• Anatomic correlation: Femoral-popliteal disease causes calf pain; iliac disease causes hip, buttock, and thigh pain 7
• When to consider: Patients over 50 years with atherosclerotic risk factors 7, 8

Diagnostic Approach

Start with focused physical examination of the adductor enthesis and muscle belly:

• Palpation: Point tenderness at the adductor longus origin on the pubic bone or along the muscle belly 3, 2
• Resisted adduction testing: Pain with resisted hip adduction confirms adductor involvement 4, 2
• Functional assessment: Pain with single-leg stance, cutting movements, or kicking motions 2

Imaging is not immediately necessary for acute adductor strains but may be indicated if:

• Symptoms persist beyond 6-8 weeks despite conservative management 3
• Concern for complete rupture or avulsion injury 2
• Need to exclude other pathology (hip joint, pubic bone stress injury) 1

Management Strategy

Acute Phase (First 2-3 Weeks)

Immediately reduce training intensity and volume to prevent progression to complete rupture. 9

• Activity modification: Avoid high-impact activities and movements that reproduce pain 9, 2
• Pain management: Acetaminophen is preferred first-line for mild-to-moderate pain, as it provides comparable relief to NSAIDs without gastrointestinal side effects 9
• NSAIDs: Use lowest effective dose for shortest duration, as they may delay natural healing by suppressing necessary inflammatory responses 9

Rehabilitation Phase (Weeks 3-12)

Eccentric strengthening of the adductors is the cornerstone of rehabilitation. 4, 2

• Progressive loading: Begin with isometric exercises, advance to eccentric strengthening, then sport-specific movements 4, 2
• Core stability: Incorporate core strengthening to improve functional activity and reduce recurrence risk 4
• Load progression: Follow the 10% rule—increase weekly training volume by no more than 10% per week 9
• Frequency: Allow minimum 48 hours recovery between high-intensity sessions 9

Refractory Cases (>8-12 Weeks)

If symptoms persist despite 8-12 weeks of conservative management:

• Consider adductor enthesopathy: MRI can identify entheseal pathology at the adductor origin 3
• Entheseal pubic cleft injection: Single injection of local anesthetic and corticosteroid provides pain relief in 68-75% of recreational athletes at one year, regardless of MRI findings 3
• Obturator nerve evaluation: If neurologic symptoms present, consider EMG and surgical consultation for potential neurolysis 5, 6

Critical Clinical Pitfalls

• Do not ignore bilateral symptoms: Bilateral presentation suggests systemic disease (vascular, spinal stenosis) rather than isolated muscle strain 9, 7
• Avoid prolonged immobilization: This leads to muscle deconditioning, increased pain, and learned non-use 9
• Do not rush return to activity: Pain during or after activity indicates overload; rest until symptoms resolve, then resume at lower level 1, 2
• Training errors are the most common modifiable risk factor: Ensure adequate recovery and gradual load progression 9