The sciatic nerve arises from the ventral and dorsal rami of L4, L5, S1, S2, and S3of spinal cord.
Branches:
Articular branches:
They supply the hip joint.
When the sciatic nerve passes the hip joint it crosses the piriformis muscle where it may interrupt termed as piriformis syndrome.
Sensory branches:
· Lateral cutaneous nerve of thigh
· Posterior cutaneous nerve of thigh
Motor branches:
· Tibial nerve
· Common peroneal nerve or Fibular nerve
Sciatic nerve supplies semimembranosus, semitendinosus, gracilus muscles, adductus Magnus and Bicep femoris.
The tibial nerve supplies calf muscles and muscles of the foot.
Common peroneal nerve supplies the anterior compartment (extensor) of leg.
Definition of SCIATICA:
Pain caused by compression or irritation of the sciatic nerve by a problem in the lower back is known as sciatica.
Pathologies:
i. Disc herniation
ii. Degenerative diseases
iii. Spinal stenosis
iv. Spondylolesthesis
v. Spondoloretrosthesis
vi. Piriformis syndrome
Disc herniation:
Mostly L4 – 5 and L5 – S1
It is the protrusion of the internal structure through weak portion. Herniation may be due to lateral flexion and rotation.
Types:
1. Central disc herniation
2. Lateral disc herniation
Sign and symptoms:
o Pain, tingling and numbness to one or both lower limbs
o Physical examination:
o Limping gait
o SLR:
Passive SLR if pain produces 60˚ - 70˚
Treatment:
o Posture education
o Spinal extension
§ Back extensor strengthening exercises
§ Extension of spine
§ Leg with straight knee
§ Supine lying bridging exercises
§ Back extensor static exercises
Spinal stenosis:
The narrowing of spinal canal is called spinal stenosis. Spinal canal is the foramen between the two vertebrae through which spinal cord passes.
Classification:
A. Cervical spinal stenosis (very dangerous)
B. Lumbar spinal stenosis
Spinal cord ends at L2 (L1 in children) in adults. Below the L2 vertebra the nerve root is compressed not the spinal cord. The nerve root compression leads to sciatica.
Causes:
Ø Tumor
Ø Infection
Ø Arthritis (common OA)
Ø Congenital
Ø Spondylolesthesis
Clinical features:
Ø Back ache or cervical ache
Ø Pain in walking and long standing to lower limb or limbs
Ø Pain on spinal extension
Ø Numbness, Paresthesia, and rediculopathy
Ø Intermittent claudication:
Gradual compression of nerve with walking or prolong standing, the pain are produced in the buttocks radiating towards lower limbs.
Investigations:
v Painful walking and standing
v Painful spinal extension
v Simple X – ray: Spondolosis, OA, RA
v MRI
Treatment:
Physiotherapy:
Passive physiotherapy:
ü Hot therapy
ü TENS/Interferential therapy: Pain
ü U/S: Adhesion breakdown, M/S relaxant, decreased Inflammation and control of infection
Active physiotherapy:
ü Stretching exercises: Calf, Hamstring, Back stretching exercises
ü Spinal manual therapy
