Clinical examination of Sciatica - Jon

Clinical Examination

¨Nerve stretch tests

¨Used to detect nerve root irritation, usually due to a prolapsed lumbar disc

Straight Leg Raising

¨Lie the patient on their back with knee extended

¨Elevate the leg (Normal 80-90degrees of flexion is usually possible)

¨Repeat and compare with other leg

¨A positive test would show pain in the sciatic nerve between 60-70 degrees flexion

¨(Felt at the posterior surface of the buttocks to the foot)

¨Sensitivity of 91%

¨Specificity of 26%

Lasègue’s test

¨Lasègue’s test is done when the leg is elevate with the knee relaxed

¨Flexion of the knee

would hence stretch

the Sciatic nerve and

if pain is present,

Sciatica may be present

Bragard test

¨Pain is felt by dorsiflexing the foot

¨Sensitivity of 91%

¨Specificity of 26%

Cross Leg Raising

¨Cross leg raising is when the lifting of the healthy leg using the SLR method causes pain in the affected leg.

¨Sensitivity of 33%

¨Specificity of 98%

¨Patients that have a disc prolapse and nerve root irritation are likely to have a positive SLR but so are a significant number of patients who don’t have this condition

¨However a positive crossed SLR test argues for a disc prolapse and nerve irritation

Others

¨Other physical examination findings such as muscle weakness, sensation and reflexes should be used in a neurological examination of the back