How Is Sciatica Related to Knee Pain?

What Is Sciatica?

When the sciatic nerve in the lower back is compressed or inflamed, the pain spreads down the hip, the outer side of the leg, and the back. Sciatica can cause tingling and numbness in the legs and feet in some people. Sciatica is a common and treatable illness, but it can be painful and debilitating in extreme situations.

What Are the Sciatic Nerves?

The sciatic nerve is the largest nerve of the human body. It is derived from the sacral plexus.

• Origin- It comes from the anterior rami of the lower lumbar and upper sacral spinal nerves (L4, L5, S1, S2, and S3). It contains fibers from both posterior and anterior divisions. In the posterior pelvic region, the anterior branches of these five spinal nerves meet and converge to form a single big nerve. The sciatic nerve then descends posteriorly through the larger sciatic foramen and exits the pelvis.

• Course- The sciatic nerve arises from the lumbosacral area. It descends through the back of the leg (posterior thigh region). The nerve splits into two big terminal branches before entering the popliteal fossa-

  • The tibial nerve.

  • The common fibular (peroneal) nerve.

• Function- The sciatic nerve's primary role is to deliver sensory and motor input to the skin and muscles of the thigh, leg, and foot.

  • Motor Supply- The muscles of the posterior thigh, the posterior, anterior, and lateral compartments of the leg, the ischial component of the adductor magnus, and the foot muscles

  • Sensory Supply- The lateral and posterior legs, posterior thigh, sole, and dorsum of the foot.

What Are the Causes of Sciatica?

Sciatica is a term that describes a group of symptoms brought on by an underlying medical disease; it is not a medical diagnosis.

The following conditions may cause sciatica,

• Muscle spasm or inflammation of the pelvic or lumbar muscles.

• Dysfunction of the sacroiliac joint.

• Lumbar degenerative disk disease.

• Herniated or slipped lumbar disk.

• Spondylolisthesis.

• Lumbar spinal stenosis.

• Osteoarthritis.

• Other rare causes - Blood clots, tumors, or conditions affecting the lower back spine.

What Are the Symptoms of Sciatica?

Sciatica symptoms are most typically noticed along the course of the sciatic nerve. One or more of the following symptoms are common in sciatica,

• Sciatic pain is like shooting pain or a constant burning sensation that starts from the lower back or buttocks and radiates down the front or back of the thigh up to the feet.

• Numbness, tingling, or weakness in the back of the leg.

• Sciatica mainly affects and causes pain in only one side of the body. However, both legs can be affected rarely.

• Sciatica symptoms may worsen when changing the posture like sitting, standing up, bending the spine forward, twisting the spine, lying down, or coughing. Walking or using a hot pack to the back of the pelvis can help ease discomfort.

What Are the Risk Factors of Sciatica?

A person can be at a higher risk of sciatica due to following reasons-

• Pregnancy.

• Lower back or spinal injury.

• Aging.

• Overweight.

• Lack of strong core muscles.

• Active and physically straining job.

• Lack of proper posture.

• Diabetes.

• Smoking.

• Osteoarthritis.

• Inactive lifestyle and prolonged sitting.

How Does Sciatica Affect Knee?

The nerve responsible for sciatica (sciatic nerve) starts from the back of the pelvis and runs up to the feet on both sides. If this nerve becomes inflamed, damaged, and causes pain in the knee area, this is called sciatica of the knee.

Sciatica of the knee may be,

1. Acute (less than six weeks), or

2. Chronic (more than six weeks).

Sciatica causes pain in the buttocks, thighs, calf muscles, foot, and sometimes knee. The pain is felt in one leg at a time.

The following signs and symptoms can be observed in sciatica when it affects the knees.

• Pain originates from the lumbar spine or the lower back and radiates to the knees.

It is often accompanied by,

• Numbness.

• Spasms.

• Weakness.

• Tingling or pins and needles sensation.

• Knee Pain Accompanied by Back Pain - The spinal cord connects the knees and back via a nerve branch that regulates the lower extremities. If the nerve is pinched or a bulging lumbar disk is present, the pain can be radiated to the knees from the lower back, where the nerve branch is located. For some people, this explains why they only feel pain in their knees and not in their backs.

• Tightness in the Hamstrings - The hamstrings are a band of muscles in the rear of the thighs. When these muscles are tense, the stability of the lower back gets disturbed. The typical curvature of the lower spine adjusts to the requirement as stress builds up in the spinal joints. Lower back discomfort and stiffness radiate down the knee and leg. The knees cannot function properly and may get damaged on moving around with tight hamstrings.

• Weak Hips or Quadriceps - If the nerves (that control the motor functions of the quadriceps are located between the vertebrae of the lumbar spine) become irritated or get pinched by the vertebrae, the movement of the hips and quads gets affected. Weakness in these areas causes the knee joints to work harder and wear out faster, leading to knee pain.

• Formation of Bunions - Bunions or bone spurs can grow on the feet due to a back problem. The person cannot run, walk, or stand due to weak or injured muscles. Foot pronation occurs when the major tendon remains misplaced and maintains the big toe joint slanted unnaturally, putting pressure on the joint and potentially causing bunions.

What Are the Causes of Sciatica of the Knee?

The following are the possible causes of sciatica of the knee,

• Prolapsed disk.

• Spinal stenosis.

• Trauma to spine.

• Malignancy.

• Infection.

• Bone diseases.

What Are the DO’s and DON'Ts for Knee Pain in Sciatica?

Things to Do on Experiencing Knee Pain During Sciatica -

• Professional help and opinion must be obtained if knee pain affects day-to-day activities and the quality of life.

• Several tests like X-rays, MRI (magnetic resonance imaging), or CT (computed tomography) scans can be done to obtain an accurate diagnosis.

• Physiotherapy should be done to treat sciatica of the knee.

Things Not to Do on Experiencing Knee Pain During Sciatica -

• Activities that aggravate the symptoms should be avoided.

• Knee symptoms during sciatica should not be ignored as untreated cases can worsen and delay recovery.

What Is the Treatment for Knee Pain in Sciatica?

Physiotherapy can help reduce the symptoms of sciatica in the knee. The physiotherapist can create a program specific to the requirements and objectives of a particular patient.

The following are some of the possible treatments,

• Hydrotherapy - Hydrotherapy is the practice of performing exercises and particular physiotherapy procedures in warm water to relieve pain, relax and strengthen muscles, enhance circulation, and improve function.

• Electrotherapy Manipulation or Mobilization - Manual procedures such as manipulations and mobilizations are utilized to physically impact a joint.

• Proprioceptive Exercise - Exercises that challenge and develop proprioceptive receptors are known as proprioceptive exercises. During static and dynamic functional tasks, proprioception aids in the stabilization of a joint.

• Postural Realignment - It is done to improve the posture by identifying any tight or weak muscles causing pain, joint stiffness, or hypermobility.

What Is the Management of Sciatica?

The goal of treatment is to help individuals feel better and move around more comfortably. Many cases of sciatica go away over time with relatively basic self-care therapies, depending on the cause. The following measures can be taken for the management of sciatica-

• Self-Care Management - The following self-care tips can help to relieve the sciatic pain-

  • Application of ice packs or hot packs alternatively. Electric hot water bags can be purchased to help in hot compressions.

  • Performing gentle stretches for general strengthening, core muscle strengthening, and aerobic exercises.

  • Taking over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) like Aspirin or Ibuprofen.

• Medical Intervention - Muscle relaxants, such as Cyclobenzaprine, may be prescribed by a healthcare professional to alleviate the discomfort caused by muscle spasms. Tricyclic antidepressants and anti-seizure drugs are two other pain-relieving medicines that doctors might prescribe. In addition, prescription pain medications may be employed early in the treatment plan, depending on the severity of the discomfort.

• Physiotherapy - Physical therapy aims to find exercise movements that relieve sciatica by lowering nerve pressure. Stretching exercises to enhance muscle flexibility and cardiovascular exercises should be part of the workout regimen.

• Spinal Injections - An injection of corticosteroid, an anti-inflammatory drug, into the lower back may assist in relieving discomfort and swelling around the damaged nerve roots. Injections provide pain relief for a brief period of time (usually up to three months) and are administered as an outpatient procedure under local anesthesia.

• Alternative Therapies - Spinal manipulation by a licensed chiropractor, yoga, or acupuncture are all options for relieving sciatic discomfort. Massage may help with muscle spasms, which are common with sciatica. Biofeedback is a technique that can be used to manage pain and stress.

• Spinal Surgery - When no other methods work, surgery is usually the last option. The goal of spinal surgery for sciatica is to relieve pressure on pinched nerves while also ensuring that the spine is stable. The most commonly used surgical techniques are-

  • Microdiscectomy: This is a minimally invasive surgery for removing herniated disk pieces that are pushing on a nerve.

  • Laminectomy: The lamina (the roof of the spinal canal) that is putting pressure on the sciatic nerve is removed during this surgical treatment.

Conclusion:

Sciatica can cause knee pain as the sciatic nerve runs from the back of the pelvis and ends at the feet. The majority of cases of sciatica in the knee can be treated with a curated physiotherapy program, albeit the length of treatment will depend on the severity of sciatica. Patients with chronic sciatica may be advised to have surgery, but in very rare cases. Sciatica is a common problem with good outcomes. It can generally be managed without any severe complications.