Foot drop is one of the signs of orthopaedic surgery. If the patient is seated with both lower limbs hanging naturally, foot drop is seen when the foot is in plantar flexion and completely unable to actively dorsiflex and invert or extensor. This sign can be seen in sciatic nerve palsy and common peroneal nerve palsy. In the former, the toes are neither dorsiflexed nor plantarflexed, whereas in the latter, the toes are plantarflexed; the two can be distinguished from each other. The sign can also be seen in poliomyelitis, progressive muscular dystrophy, hypokalemic periodic paralysis and lower limb paralysis.
Causes
Patients with foot drop are suffering from severe long-term compression of the nerve roots (common peroneal nerve, foot nerve, sciatic nerve, lumbosacral nerve root and cerebral nerve are all possible). Nerve dysfunction can be caused by nerve root surface pressure exceeding 50 mmHg for 2 minutes, while above 100 mmHg can lead to peripedal nerve damage, spinal motor nerve damage, myotonic dystrophy and joint flexion deformity, which in turn increases stiffness and biomechanical changes to the musculature around the joint due to activation, soft tissue deficit or scarring in a particular location, as evidenced by:
1. gastrocnemius and hallux valgus muscles: no flexion of the anterior palmar area is produced and significant movement of the heel bone is visible;
2. by the posterior tibialis, long and short peroneal muscles, the anterior palmar region is plantarflexed in relation to the posterior palmar region and no significant movement of the heel bone is seen;
3. compensated by the long toe flexors, with strong flexion of the toes;
4. compensated by the long toe flexor with flexion of the mother toe;
5. stenosis of the spinal canal, hypertrophy of the ligamentum flavum, hyperplasia and coalescence of the synovial joints, narrowing of the lateral saphenous fossa and nerve root canal, combined with calcification of the herniated discs, paralysis of the anterior and lateral calf muscle groups, and changes in the posterior calf muscles, loss of muscle tuberosities, loss of water, collagen deposition and spasmodic pulling of the viscous reformation groups, cause foot drop.
Post time: Oct-12-2022