ANATOMY OF THE SCIATIC NERVE
Sciatica and or herniated disc (HNP) are two common diagnosis that are responsible for back pain at any age. The sciatic nerve is the largest and longest nerve in the human body. During examination in gross anatomy lab it appeared to look like a very thick semi opaque fiber optic cable. It can measure up to three quarters of an inch in diameter and consists of a bundle of five nerves that branch from the lower portion of the spinal cord. At knee level the sciatic nerve splits into the tibial and common fibular nerves and controls the lower leg and foot. Within this bundle are fibers that allow us to feel sensation in the skin surrounding the hip and thigh and motor fibers that conduct movement in the hip, leg and foot.
Any problem in the lower spine can affect one of the neurons that feed into the sciatic nerve, and cause burning, pain, numbness in the hip, thigh and foot. Each patient will present with a unique combination of symptoms with sciatica.
Radiculopathy is a term used to describe pain that extends into the hip and down the leg but is usually caused from pressure on the nerve higher up in the chain. In the beginning stages this pain may feel like a fishing line pulling along the back or side of the hip and thigh. Often patients with leg pain are not aware that the source of their pain is the low back. Intensity and distribution of pain symptoms down the leg have a direct relationship to the amount of pressure being placed on the nerve further up the chain.
The mechanical pressure placed on the sciatic nerve is often referred to as impingement and can be caused by several sources.
HERNIATED DISC AS THE CAUSE OF SCIATICA:
A herniated disc (HNP) is one cause of sciatica. Shock absorbing discs are positioned between our vertebra. The disc is composed of a cartilaginous ring or annulus fibrosis and a gel like center, the nucleus pulposus. The cartilaginous ring may become injured or torn due to everyday stresses of bending, sitting, posture, wear and tear and will develop a fissure or tear and the nucleus pulposus (NP) will move out of the center. The outer third of the ring is innervated so when this happens you will often have back pain as the NP pushes into the innervated section of the ring. If the NP moves out far enough through the fissure it places pressure on nearby spinal nerve roots exiting the spinal canal. The pressure on the nerve root causes pain in the low back region or down the leg depending on the degree of herniation. The four stages of an HNP are disc 1)protrusion, 2)prolapse, 3)extrusion, 4)sequestered. The way you position your body and move during sitting, standing, twisting, or bending may or may not place stress on the fissure. This pressure may extend to the nerve root that branches off the spinal cord and send signals of pain down the leg. The good news is that in many cases of HNP you can alter your mechanical movements and strengthen your back muscles to decrease stress on the herniation and allow it to heal.
PIRIFORMIS, ADHERED FASCIA, BONE SPURS AS THE CAUSE OF SCIATICA:
The sciatic nerve runs under the piriformis muscle in some people and a tight piriformis muscle or even adhered fascia binding the nerve may also cause symptoms. Other sources of sciatica include inflammation of the nerve, bone spurs near the nerve root, muscle spasm/compartment syndrome anywhere along the route of the nerve. Less common sources of sciatica include tumors, infections or bleeding next to an adjacent bone. It is important to check in with your doctor to understand the cause of your sciatica.
COMMON SCIATICA/HNP SYMPTOMS:
The following symptoms are common: prickly burning pain anywhere in the hip, leg, or foot, weakness at the knee, tingling in the web between the big and 2nd toe, drop foot, difficulty bearing weight through the leg and raising the heel. Pain is often exacerbated with coughing, impact movements and sitting in particular.
Sciatica and HNP can present in a variety of ways and depending on the severity and the cause of sciatica, different treatments may be warranted for each individual case. Decreasing irritation and stress on the fissure or outer third of the cartilaginous ring of the disc and nerve root through body positioning can be helpful. It is important to address the mechanical balance around each segment of the spine through strengthening exercise and precise core stabilization. This may vary from patient to patient.
What does the research show?
- One outcome study from Spine ( Saal 1989) showed that patients with radicular symptoms improved with exercise-based physical therapy in 3 months. 90% of patients had good to excellent outcomes with 92% returning to work in 3 months. When the disk was extruded (completely pushed though annulus) 87% had good outcomes and 83 % had excellent outcomes.
- A study in the New England Journal of Medicine (Ramaswami 2017) showed that 60% of patients with classic radiculopathy treated non-operatively avoided surgery.
- A study by Lurie in 2014 showed surgery was a better option only if the patients were carefully selected.
- Koszela showed that specialized rehabilitation had a significant effect on decreasing pain in the treatment of patients with back pain secondary to a herniated disc. Recommends that rehab be considered first before spine surgery.
- Gugliotta 2016 showed that while surgery gave faster relief from sciatica caused by a lumbar disc herniation, conservative treatment proved an equally good alternative in midterm and long term follow up.
PHYSICAL THERAPY & GOOD NEWS
The good news is that in many cases physical therapy (conservative treatment) can help! Once the source of the sciatica is determined, a combination of postural positioning and carefully chosen exercises, suited to the mechanical nature of the pain source, can make recovery possible. Precisely executed exercises will protect the spine and decrease symptoms. When proper strengthening is combined with fascial release techniques, joint mobilizations, and nerve glides, recovery is soon to come. The source of your sciatica should be determined to rule out unusual causes. Treatment should be done under the guidance of a licensed professional who understands the mechanical nature of your medical diagnosis.
In the meantime, here are some general tips that may help you until you are able to see a professional.
- Avoid heavy and repetitive lifting to decrease further injury.
- Square off your body while sitting and standing and while having conversations etc.
- Avoid twisting and bending from the waist. Move like a robot for a period of time.
- Note which positions ease your symptoms and which aggravate them and avoid the irritable positions. Listen to your body and let your symptoms be your guide.
- Rubber soled shocking absorbing shoes are beneficial.
- Avoid impact activities like running and jumping
- Sleeping with a neutral spine will decrease irritation
- Sitting on firm flat high seats tend to improve low back position and will decrease symptoms. Avoid low cushiony sofas and seats.
- Gentle low impact, neutral spine activity may keep nutrition flowing to the spine and stave off the effects of guarding. Let your body be your guide.
- Change positons every 20-30 minutes.
SEE A MEDICAL PROFESSIONAL:
See a medical professional to understand the cause of your sciatica. A physical therapist will understand which exercises aide healing and will know which exercises to avoid. Carefully chosen exercises and manual therapy will assist in recreating the proper firing patterns of the muscles around the spine to relieve pain. Choose a therapist who spends plenty of one on one time with you and supervises the nuances of your form when performing the exercises. Good physical therapy will make all the difference. A physical therapy program should evolve overtime to meet your needs so you can return to function and a pain free life.
The contents of this blog are for informational purposes only and are not a substitute for professional medical advice, diagnosis, or treatment.
Biel, Andrew. Trail Guide the Body , 3rd Edition.2015. Books of Discover Boulder ,Co
Saal Ja, Saal JS. Nonoperative treatment of herniated lumbar intervertebral disc with radiculopathy: an outcome study. Spine (Phila Pa 1976)1989;14:431-437 result.
Ramaswami,R, Ghogawala Z, Weinstein JN. Management of Sciatica, N Engl J Med 2017 March 23,2017: 376(12):1175-1177 DOI: 10.1056/NEJMcide1701008 PMID:28328334.???
Lurie JD et al. Surgical versus nonoperative treatment for lumbar disc herniation:eight-year results for the spine patient outcomes research trial. Spine(Phila Pa1976) 2014;39:3-16.
Koszela K et al. The assessment of the impact of rehabilitation on the pain intensity level in patients with herniated nucleus pulposus of the intervertebral disc. Pol Merkur Lekarski. 2017 May 23;42(251):201-204.
Gugliotta M et al, Surgical versus conservative treatment for lumbar disc herniation: a prospective cohort study. BMJ Ope. 2016 Dec 21:6(12):e012938. Doi:10.1136/bmjopen-2016-012938. PMID28003290