Piriformis syndrome
- Piriformis gets hypertonic |
- Hypertonic piriformis presses on proximal sciatic nerve |
- Neurological ischaemia, congestion, local inflammation and radicular complaints |
- Sciatic nerve can pass through the muscle instead of deep in some people |
- Sciatic nerve does not innervate butt or posterior thigh (innervates sensation of LL and foot ) |
- Pain in the butt and posterior thigh thought to be because of compression of inferior gluteal vein - ischemia to posterior femoral cutaneous nerve |
- Chronic cases can lead to perineural adhesions in the sciatic nerve |
Risk Factors
- Morton foot (longer 2nd digit) can be a risk |
- 40-60 yo |
- Affects women - Q angle |
- Affects people who sit on their wallets in their back pocket (hip pocket wallet) |
Presentation
- Trauma or develops slowly |
- Strain, fall on buttocks or catching oneself from a near fall |
- Repetitive microtrauma - long distance walking, stair climbing, chronic compression |
- Paresthesia or numbness in the gluts and radiates along the sciatic nerve |
- Trigger point referral into proximal thigh, SI and hip |
- Aggravated by holding a position for longer than 15-20 minutes - prolonged sitting/standing, hip int rot (crossed legged) |
- Discomfort when walking, running, stair climbing, riding in a car or arising from a seated position |
- Can be a antalgic gait |
- Hypertonic piriformis and obuturator internus, TFL, obturator externus, adductor and gluteal muscles |
- SI joint dysfunction, restrictions in LL and spine |
- Assess arch of foot and Leg length |
- Assess for externally rotated hip at rest |
- PROM hip internal rot |
- +ve FAIR +ve SLR |
- SMR can reveal neurological changes (not proximal thigh weakness) |
- Assess for other entrapments (gemeli-obturator internus syndrome, ischiofemoral impingement syndrome, proximal hamstring syndrome |
Imaging
- Not usually required |
- Advanced imaging to rule out other radicular complaints |
- Electrodiagnostic testing |
- US |
DDx
- Hip pathology |
- F# |
- Lx compression |
- Discitis |
- Trochanteric bursitis |
- Sacroiliitis |
- SI dysfunction |
- Lx radiculopathy |
- Spinal stenosis |
- Viscerosomatic referred pain |
Management
- Limit activities - hill and stair climbing, walking on uneven surfaces, intense downhill running/twisting, throwing objects backward |
- Avoid sitting on one foot, take breaks from standing, sitting and car rides |
- Limit sustained hip ext rot and abduction |
- Stretching of piriformis |
- Myofascial release of gluts, obturator, tensor fascia lata, hamstring, lx erectors, hip adductors |
- SMT/EMT of lx, SI, LL |
- Heat/ice |
- Ultrasound |
- Strengthening of abductors, adductors and gluts |
- Heel lift for leg length inequality |
- Muscle relaxants, steroids, trigger point injections, botox for faillure to respond to con care |
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