A variety of factors could cause symptoms associated with sciatica, which is an umbrella term that includes pain in the back/buttock (which may radiate down the leg), numbness in the affected area, tingling sensations and muscle weakness. Finding out the specific cause of sciatica is especially important for the proper treatment, as each cause has a different approach.
Three of the most common causes of sciatica are a lumbar herniated disk; degenerative disk disease; and piriformis syndrome. All of these conditions can lead to an irritation of the sciatic nerve, causing the symptoms associated with sciatica.
3 Common Causes of Sciatica
1. Lumbar Herniated Disc
The most common cause of sciatica is a herniated disk in the lumbar spine, also known as a slipped disk, or a disk protrusion in milder cases. Between each vertebra of the spine is a gel-like substance surrounded by fibrous tissue, known as an intervertebral disk. Abnormal loading of the spine, such as repetitive twisting or bending movements, can weaken the fibrous portion of the disk. Once sufficiently weakened, the gel-like substance of the disk spills out, compressing the nerve roots of the spine.
A physiotherapist can identify during the assessment at which level and direction the disk is protruding from, as well as the associated exercises to help push the disk back in place. In addition, strengthening exercises and postural education designed to prevent a re-injury are given. Physiotherapy treatments are aimed at helping the disk slip back into place as well as reducing the associated muscle tension around the injury site. Acupuncture may also be given to help relieve the pain and numbness symptoms associated with a herniated disk.
2. Degenerative Disk Disease
While in cases of herniation, the intervertebral disk slips out, in cases of degenerative disk diseases (DDD) the disk loses its hydration and elasticity. When this occurs, the disks are unable to fulfill their primary function – to help absorb shocks and providing mobility between the vertebrae. In severe cases of DDD, the disk may collapse entirely, causing compression on spinal nerve roots and bringing on sciatica symptoms. X-rays are often used to diagnose cases of DDD.
Pain reduction from DDD involves reducing the stress and pressure placed on the spine, in addition to physical modalities such as electrotherapy and ice/heat. Core strengthening exercises to stabilize the spine are also especially helpful in DDD, as it helps reduce the load it experiences. Other approaches to help reduce the load on the spine include lifestyle changes, such as weight loss and improving one’s daily posture.
3. Piriformis Syndrome
When one thinks of sciatica, one usually thinks the condition is caused by a problem coming from the back. However, a common cause of sciatica pain is caused by the compression of the sciatic nerve from muscle tightness. The sciatic nerve travels through a muscle near the buttocks called the piriformis, and excessive tightness in that muscle could irritate the nerve. The pain often increases with prolonged sitting and walking up stairs or inclines, and is often associated with a near-constant dull ache in the buttock region.
The primary management strategy for piriformis syndrome is reducing the tightness of the muscles in the region. This is done via stretching protocols, manual release through massages and trigger point release, and modalities such as acupuncture and shockwave therapy. Reducing the time spent sitting and exercises that trigger the pain is also recommended.