Populations and Risk Factors
- Contact sport athletes (football, hockey, lacrosse, soccer)
- Any activity with risk of direct hip impact or falling onto the lateral pelvis
- Athletes without adequate protective padding over the iliac crest
- Adolescents at increased risk because the ASIS apophysis is not yet fused (risk of avulsion fracture)
Causes and Pathophysiology
- Direct blow mechanism: Impact force strikes the superficial ASIS, causing bruising of the bone (periosteal contusion) and overlying soft tissue (muscle, fascia, subcutaneous tissue)
- Muscle attachment involvement: The ASIS serves as the attachment point for the sartorius (hip flexion and lateral rotation) and the inguinal ligament. TFL originates nearby along the anterior iliac crest — contusion at these origins produces pain with any hip movement that loads these muscles
- Periosteal reaction: Direct bone bruising triggers a periosteal inflammatory response with significant swelling and pain. The periosteum is richly innervated, explaining the severe tenderness
- Avulsion risk in adolescents: In skeletally immature athletes, sudden forceful contraction of the sartorius can avulse the ASIS apophysis rather than merely bruising it — this is a fracture requiring medical management, not a simple contusion
- Secondary complications: If untreated, prolonged guarding and gait compensation can lead to hip flexor contracture, ITB tightness, and compensatory low back pain
Signs and Symptoms
- Exquisite tenderness directly over the ASIS or along the iliac crest
- Ecchymosis (bruising) and swelling at the anterolateral hip
- Increased pain with trunk rotation, hip flexion, and resisted hip movements
- Antalgic gait or limp from inability to stabilize the pelvis during walking
- Pain with coughing, sneezing, or laughing (abdominal muscles attach to the iliac crest)
- Red flags: Inability to bear weight at all or sudden sharp pain during muscle contraction (suspect ASIS avulsion fracture in adolescents — refer for imaging)
CMTO Exam Relevance
- CMTO Appendix category A1 (MSK conditions)
- Key differential: hip pointer vs. ASIS avulsion fracture — avulsion presents with inability to flex the hip against resistance and may show a palpable gap at the ASIS
- Thomas Test is a CMTO-essential test relevant to hip flexor assessment in this context
- Understand that compensatory patterns from hip pointer can affect the kinetic chain (knee, low back)
Massage Therapy Considerations
- Acute phase: PRICE protocol. Do not work directly on injury site during active inflammation (first 48-72 hours)
- Post-acute: Restore normal muscle resting lengths of hip flexors, TFL, and sartorius. Address hip imbalances creating compensatory distortions affecting knees and lower legs
- Positioning: Bolster behind knees in supine to shorten hip flexors and reduce traction on the injured ASIS
- Associated tension: TFL and sartorius may become hypertonic as a protective response, causing secondary lateral hip or ITB pain
- Stretching: Fundamental once the acute phase subsides for restoring function. PIR to hip flexors is effective
- Referral: If symptoms do not improve within 7-10 days or the client cannot bear weight, refer for imaging to rule out avulsion fracture
Key Takeaways
- Acute phase: do not work directly on the injury site. Follow PRICE protocol for the first 48-72 hours
- Differentiate from ASIS avulsion fracture (inability to flex hip against resistance, palpable gap) — refer if suspected, especially in adolescents
- Bolster behind knees in supine to shorten hip flexors and reduce tension on the injured ASIS
- TFL and sartorius may become hypertonic as a protective response, causing secondary lateral hip or knee pain
- Stretching and restoring normal muscle resting lengths is fundamental once the acute phase subsides