How is it that lower back injury can cause pain in the lower limb?
Lumbosacral Radiculopathies
Neuropathy involving the nerve root causes:
 Compressive (wear and tear, traumatic)
 Infectious
 Malignant
 Inflammatory
Pain may originate in lower back and radiate in the distribution of the involved root(s). Irritation of
the nerve root can lead to weakness, pain, or sensory deficits.
Musculoskeletal lower back pain: (LBP) is pain, stiffness, and/or soreness of the lumbosacral
region (underneath the twelfth rib and above the gluteal folds) persisting for <12 weeks. The exact
cause of pain is often impossible to identify precisely, but arises from any combination of
pathology involving discs, vertebrae, facet joints, ligaments, and/or muscles.
 Radiculopathy/Sciatica: Numbness, weakness in lower extremities, pain radiating to
buttock and leg (especially if the pain radiates beyond the knees). Radiculopathy/sciatica is
often unilateral.
 Spinal Compression Fracture: Spine tenderness on palpation, particularly in older patients
with a history of steroid treatment and/or osteoporosis.
 Sacroilliac Pathology: In addition to LBP, pain is also common in the buttocks and upper
thighs.
Spinal tumour: a benign or malignant spinal tumour can present with back pain with radicular
symptoms due to nerve compression. The pain from a tumor is constant, dull ache associated with
loss of appetite and weight loss. If patient does not improve after 4-6weeks of conservative
treatment suspect tumour. The presence of nocturnal pain is a red flag.
Spinal Stenosis: narrowing of the vertebral canal. Pseudoclaudication in the legs, numbness,
weakness radiating beyond the knee. Stenosis is often bilateral. Common cause is Paget’s disease,
where enlargement of the vertebrae may encroach on the spinal canal.
Spinal infection can present with a gradual onset of back pain that is associated with bending and
twisting activities. It may be associated with systemic signs and symptoms and progress at a pace
that is much more rapid than that seen with a degenerative pathology.
 Arachnoiditis: Chronic inflammation of arachnoid matter nerve root sheaths in the spinal
canal can cause severe low back pain, sometimes combined with nerve root symptoms.
Degenerative disc disease- (LBP +/- leg pain)
Although a number of different spinal anatomical structures (facet joints, intervertebral discs,
vertebral bodies, ligaments, and muscles).
Radicular leg pain associated with degenerative disc disease results from nerve root compression
due to hypertrophied facet joints, disc prolapse, or foraminal narrowing due to loss of disc height
or due to instability at that motion segment.
Osteophytes (bone spurs): in the lumbar region, can cause LBP and nerve compression.
Cauda Equina Syndrome: Signs and symptoms include GI/GU incontinence or retention, saddle
anaesthesia, and sudden unexplained bilateral lower-extremity weakness.