lumbosacral plexus and sciatica

LUMBAR & SACRAL PLEXUS

Sciatic Nerve

Peripheral nerves in lower quadrant

• The lumbosacral plexus terminates in three primary peripheral nerves

• These are responsible for innervating the tissues of the lower extremity

• Lumbar plexus – Femoral & obturator nerves

• Sacral plexus – Sciatic nerve

Nerve Muscle affected with nerve injury

Common sites of nerve Compression / tension or causes of nerve injury

Deformity / symptoms

Primary functional loss

Femoral (L2 – L4)

Illiacus Sartorius Pectineus Quadriceps

Pelvic or upper femur fractureDuring reduction of DDHPressure during forceps delivery

Atrophy in anterior thigh

Weakness or inability to flex thigh and extend kneeGait and weight bearing disturbances: unable to control knee flexion during loading response





Obturator (L2 – L4)

Obturator externusAdductor muscle groups

Pelvic or upper femur fractureDuring reduction of DDHPressure during forceps deliveryPressure from gravid uterus and difficult labour

Atrophy in medial thigh

Difficulty in crossing legsImpaired adduction & external rotation of thigh





Sciatic (L4 – S3)

Hamstring groupAdductor magnus

Compression from tight piriformisHip dislocation # of femur

Sciatica – Pain radiating in posterior thigh and legAtrophy posterior thigh , leg & footAtrophy in calf

Weak knee flexion and loss of ankle and foot control affecting all phases of gait





Tibial (L4 – S3)

Distal to ankleMedial and lateral plantar nerves

Plantar flexorsPopliteus Tibialis posterior Flexor digitorum longus Flexor hallucis longus

Distal to ankleAbductor hallucisFlexor hallucis brevis Lumbricales Interossei Quadratus plantae

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Ankle and footCompromise in tarsal tunnelIrritation from pes planus or pes cavus

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Foot deformitiesPes cavus Claw toes Foot strainPainful heel

Inability to plantar flex ankle or flex the toesGait impairment in terminal stance

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Common peroneal (L4 – S2)

Deep peroneal nerve

Superficial peroneal nerve

Ankle dorsiflexors Toe extensors Peroneus tertius

Peroneus longus and brevis

Compression from crossing legs Injury from # at head/neck of fibula Foot drop

May develop pes valgus

May develop equinovarus

Gait impairment during the loading response with foot slap and during swing phase with excessive flexion ( steppage gait ) to clear the toes

Sciatic Nerve

Sciatica

Introduction The sciatic nerve is the thickest nerve in the

human body In its upper part, it forms a band about 2 cm It begins in the pelvis and terminates at the

superior angle of popliteal fossa by dividing in to the tibial and common peroneal nerves

Origin and Root value This is the largest branch of sacral plexus Root value – L4, L5, S1, S2, S3 It is made up of 2 parts, the tibial part and

common peroneal part The tibial part is formed by the anterior

primary rami of L4, L5, S1, S2, S3 The common peroneal part is formed by the

dorsal division of the anterior primary rami of L4, L5, S1, S2

Course Pelvis – The nerve lies in front of the

piriformis, under cover of its fascia Gluteal region – The nerve enters the gluteal

region through the greater sciatic foramen below the piriformis – It runs downwards and passing between the ischial tuberosity and the greater trochanter

Thigh – Enters back of the thigh at the lower border of the gluteus maximus– It runs vertically downwards up to the

superior angle of the popliteal fossa, at the junction of the upper two – third and lower one – third of the thigh, where it terminates by dividing in to the tibial and the common peroneal nerves

Relations Gluteal region:

– Medial:• Inferior gluteal nerve and vessels

– Superficial or posterior:• Gluteus maximus

– Deep or Anterior:• Body of the ischium• Tendon of obturator internus with the gemelli• Quadratus femoris, obturator externus• The capsule of the hip joint• The upper, transverse fibres of the adductor

magnus

Thigh: Small companion artery branch of inferior gluteal artery– Superficial / Posterior:

• Crossed by long head of biceps femoris– Deep / Anterior:

• Lies on the adductor Magnus– Medial:

• Semimembranosus & Semitendinosus– Lateral:

• Biceps femoris

Muscles & Nerve Supply Semitendinous TS Semimembranosus TS Biceps femoris LTS SCP Adductor magnusCP

SCIATICA It is a common type of pain

affecting the sciatic nerve, a large nerve extending from the lower back down the back of each leg.

Causes Sciatica is caused by irritation of the root(s) of

the lower lumbar and lumbosacral spine. Lumbar spinal stenosis (narrowing of the

spinal canal in the lower back) Degenerative disc disease (breakdown of

discs, which act as cushions between the vertebrae)

Spondylolisthesis (a condition in which one vertebra slips forward over another one)

Pregnancy Other things that may make your back

pain worse include being overweight, not exercising regularly, wearing high heels, or sleeping on a mattress that is too soft.

Symptoms Pain in the rear or leg that is worse when

sitting Burning or tingling down the leg Weakness, numbness, or difficulty moving the

leg or foot A constant pain on one side of the rear A shooting pain that makes it difficult to stand

up Sciatica usually affects only one side of the

lower body The pain extends from the lower back all the

way through the back of the thigh and down through the leg

Depending on where the sciatic nerve is affected, the pain may also extend to the foot or toes

In Severe cases lower extremity weakness, numbness in the upper thighs, and/or loss of bladder or bowel control.

Loss of knee flexion due to weakness of hamstring group of muscles

Risk factors Age. Age-related changes in the spine, such

as herniated disks and bone spurs, are the most common causes of sciatica.

Obesity. By increasing the stress on your spine, excess body weight may contribute to the spinal changes that trigger sciatica.

Occupation. A job that requires you to twist your back, carry heavy loads or drive a motor vehicle for long periods may play a role in sciatica, but there's no conclusive evidence of this link.

Prolonged sitting. People who sit for prolonged periods or have a sedentary lifestyle are more likely to develop sciatica than active people are.

Diabetes. This condition, which affects the way your body uses blood sugar, increases your risk of nerve damage.

Complications Although most people recover fully from

sciatica, often without any specific treatment, sciatica can potentially cause permanent nerve damage

Loss of feeling in the affected leg Weakness in the affected leg Loss of bowel or bladder function

Tests During the physical exam, your PT may check

your muscle strength and reflexes. For example, you may be asked to walk on

your toes or heels, rise from a squatting position and, while lying on your back, lift your legs one at a time straight in the air. Pain that results from sciatica will usually become worse during these activities.

Investigations X-ray. An X-ray of your spine may reveal an

overgrowth of bone (bone spur) that may be pressing on a nerve.

Magnetic resonance imaging (MRI). MRI produces detailed images of bone and soft tissues such as herniated disks

Management Medical : The types of drugs that might be prescribed

for sciatica pain include: Anti-inflammatories Muscle relaxants Narcotics Tricyclic antidepressants Anti-seizure medications

Physical Therapy

Once your acute pain improves, your physical therapist can design a rehabilitation program to help you prevent recurrent injuries.

This typically includes exercises to help correct your posture, strengthen the muscles supporting your back and improve your flexibility.

To reduce compression – Traction To reduce pain – Ultrasound therapy & TENS

or IFT

Alternative Medicine Acupuncture. In acupuncture, the

practitioner inserts hair-thin needles into your skin at specific points on your body. Some studies have suggested that acupuncture can help back pain, while others have found no benefit.

Chiropractic. Spinal adjustment (manipulation) is one form of therapy chiropractors use to treat restricted spinal mobility. The goal is to restore spinal movement and, as a result, improve function and decrease pain. Spinal manipulation appears to be as effective and safe as standard treatments for low back pain

Surgery

This option is usually reserved for times when the compressed nerve causes significant weakness, bowel or bladder incontinence or when you have pain that progressively worsens or doesn't improve with other therapies.

Surgeons can remove the bone spur or the portion of the herniated disk that's pressing on the pinched nerve.

Home Remedy Cold packs. Initially, you may get relief from

a cold pack placed on the painful area for up 20 minutes several times a day. Use an ice pack or a package of frozen peas wrapped in a clean towel.

Hot packs. After two to three days, apply heat to the areas that hurt. Use hot packs, a heat lamp or a heating pad on the lowest setting. If you continue to have pain, try alternating warm and cold packs.

Stretching. Stretching exercises for your low back can help you feel better and may help relieve nerve root compression. Avoid jerking, bouncing or twisting during the stretch and try to hold the stretch at least 30 seconds.

Over-the-counter medications. Pain relievers such as ibuprofen (Advil, Motrin, others) and naproxen (Aleve) are sometimes helpful for sciatica.

Prevention It's not always possible to prevent sciatica,

and the condition may recur. The following suggestions can play a key role in protecting your back:

Exercise regularly. This is the most important thing you can do for your overall health as well as for your back. Pay special attention to your core muscles — the muscles in your abdomen and lower back that are essential for proper posture and alignment.

Maintain proper posture when you sit. Choose a seat with good lower back support, arm rests and a swivel base. Consider placing a pillow or rolled towel in the small of your back to maintain its normal curve. Keep your knees and hips level.

Use good body mechanics. If you stand for long periods, rest one foot on a stool or small box from time to time. When you lift something heavy, let your lower extremities do the work. Move straight up and down. Keep your back straight and bend only at the knees. Hold the load close to your body. Avoid lifting and twisting simultaneously. Find a lifting partner if the object is heavy or awkward.

TANKIEW

lumbosacral plexus and sciatica

Health & Medicine