The Science of SCI How Injury Impacts Function

When it comes to spinal cord injuries (SCIs), location is critical: It significantly impacts how the patient’s function and sensation will be affected (though other factors can also determine how much function is ultimately lost). In addition to the descriptions below—describing the effects of injury starting at the portion of the spinal cord nearest the skull, then moving downward—SCIs are also described as complete (no sensation or voluntary movement below primary injury area) or incomplete (some sensation and voluntary movement below injured area).

Cervical Injuries
C1: Located directly at the base of the skull, it is referred to as the atlas because it holds the globe of the skull. The C nerves supply movement to the arms, neck and upper trunk.
C2: Allows the head to turn and tilt and is referred to as the axis. When an injury occurs in either the C1 or C2 area, the person may experience a loss of involuntary functions, such as the ability to breathe, low blood pressure, inability to regulate blood pressure effectively, reduced control of body temperature, inability to sweat below the level of injury, and chronic pain.
C3: People with C1–C3 injuries will experience limited head and neck movement; complete paralysis of the arms, body and legs; and the inability
to breathe using their chest muscles
or diaphragms. Patients will need complete assistance transferring from a bed to a wheelchair or a wheelchair to a
car and will need complete assistance with meals. Their sympathetic nervous systems will also be compromised, and assistance will be required to clear secretions from the trachea. Injuries above C4 may require a ventilator for the person to breathe properly.
C4: The fourth neck vertebrae from the top controls the area just below the clavicle. People with C4 injuries will experience limited shoulder movement while retaining full head and neck movement, depending on muscle strength. The body and legs will be completely paralyzed with no finger, wrist or elbow flexion or extension. The sympathetic nervous system will be compromised, and total assistance will be needed when transferring. This person also needs complete assistance during meals and complete domestic and personal assistance.
C5: Located down from the base of the skull, in the neck. People with this type of injury have no control at the wrist and hand, but often maintain shoulder and biceps control. C5 injuries often result in complete paralysis of
the body and legs with full head and neck movement, if there is good muscle strength. This person will not have finger or wrist movement or elbow extension. However, they will have good elbow flexion. The sympathetic nervous system will be compromised. Total assistance will be required when transferring, clearing secretions and coughing. Complete personal and domestic assistance will be needed.
C6: Covers the forearm and the thumb side of the hand. People with this injury will experience complete paralysis of the body and legs. No finger movement, elbow extension or wrist flexion will be present. These injuries generally allow wrist control, but not hand function. The person will, however, have full head and neck movement with good muscle strength and shoulder movement. Total assistance will be needed when transferring from the floor to chair; assistance will vary for transfer from bed to wheelchair and wheelchair to car. Complete domestic care is required, along with personal assistance. But the person will be able to partially dress his upper body, shave and brush hair and teeth with palm straps.
C7: Represents the middle finger and elbow extensors, while C8 represents the lateral part of the hand and finger flexors. When C7 and C8 injuries occur, they cause complete paralysis of body and legs with partial finger movement and full elbow extension and flexion along with full wrist extension and flexion. Patients with these injuries will also experience full head and neck movement with good muscle strength and good shoulder movement. A C7-injured person will have movement in the thumb. This person may need assistance making car transfers, depending on upper-body strength. The sympathetic nervous system will be compromised. Food may need cutting, but the person will be independently able to feed himself. Assistance will be required to clear secretions, and assistance in coughing may be required. The person may need assistance in lower-body dressing and showering, but can independently dress and shower upper body. Partial domestic assistance is required, but the person is usually independent in grooming.

Thoracic Injuries
T1–T4: Injuries here result in complete paralysis of the lower body and legs. People with injuries in this area will have varying levels of upper-body strength and balance, depending on injury level. The person will have good chest-muscle strength, but strength will weaken the higher up the injury is. People with these injuries will also experience full head and neck movement with normal muscle strength along with normal shoulder movement, full use of arms, wrists and fingers. Assistance during car transfers may be needed, depending on upper-body strength. The sympathetic nervous system may be compromised. The person should be independent in personal care, as long as no other factors are involved, such as additional injuries or severe spasticity. Partial domestic assistance may be required, along with assistance during car transfers, depending on upper-body strength.
T5–T9: A person with these injuries will have full head and neck movement with normal muscle strength, and normal shoulder movement along with full use of arms, wrists and fingers. Injuries in this region result in complete paralysis of lower body and legs with varying upper-body strength depending on the level of injury. The lower the level of the injury, the stronger the upper-body strength and balance will be. The person may need assistance with car transfers, depending on upper-body strength. Partial domestic assistance is required for heavy household cleaning and home maintenance. As long as other injuries don’t exist, patients should also be independent in personal care.
T10: Situated at the umbilicus; T12 ends just above the hip girdle. T10–L1 injuries affect certain parts of the abdominal and leg muscles. This type of injury results in partial paralysis of the lower body and legs. People with these injuries will experience full head and neck movement with normal muscle strength, and normal shoulder movement along with full use of arms, wrists and fingers. The strength of the upper body will vary depending on the level of injury. The person has the ability to prepare complex meals and perform general household duties independently. The person should also be independent in personal care as long as no other medical conditions are involved. Partial domestic assistance
is required for heavy household cleaning and home maintenance.

Lumbar & Sacral
Injuries here yield decreasing control of the hip flexors and legs. The sacrum is located behind the pelvis and fits below the lumbar vertebrae. Back pain or leg pain can typically arise due to injury where the lumbar spine and sacral region connect at (L5-S1), because this section of the spine is subjected to a large amount of stress and twisting. L1 to L5 represent the hip girdle and groin area. L2 and L3 cover the front part of the thighs, while L4 and L5 cover the medial and lateral aspects of the lower leg.
L2–S5 injuries affect leg muscle, bowel, bladder and sexual functions. A person with these injuries will have full upper-body control and balance along with some knee, hip and foot movement, depending on the level of injury. The patient may be able to walk with assistance or walking aids, depending on the level of injury; however, a manual wheelchair may be useful for daily living activities. The person should be independent in personal care as long as no other factors are involved.

Sources for This Story
www.spinalinjury.net/html/_spinal_cord_101.html
www.apparelyzed.com/paralysis.html
www.disabled-world.com/artman/publish/spine_picture.shtml

www.sci-info-pages.com/levels.html

This article originally appeared in the October 2008 issue of Mobility Management.

Subscribe to eMobility

Mobility Management's free email newsletter keeping you up-to-date and informed.

I agree to this site's Privacy Policy