7.1 Spinal Cord Injury Levels & Functional Milestones

Spinal Cord Injury Levels & Functional Milestones

Spinal cord injury (SCI) produces profound sensorimotor, autonomic, and functional disruptions that fundamentally alter an individual's occupational performance. Occupational therapists play a central role in guiding rehabilitation across the continuum of care—from acute positioning, splinting, and medical emergency mitigation to compensatory ADL/IADL training, assistive technology integration, wheelchair seating, and community reintegration.

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1. Spinal Cord Injury Classification & Syndromes

The neurological level of injury (NLI) is defined as the most caudal segment of the spinal cord with normal sensory and motor function bilaterally (minimum motor grade of 3/5 on manual muscle testing, provided the segment immediately above is 5/5).

+---------------------------------------------------------------------------------------------------+
|                    ASIA IMPAIRMENT SCALE (AIS) CLASSIFICATION SYSTEM                              |
+-------+-------------------+-----------------------------------------------------------------------+
| Grade | Classification    | Neurological & Clinical Definition                                    |
+-------+-------------------+-----------------------------------------------------------------------+
| **A** | **Complete**      | No motor or sensory function is preserved in sacral segments S4–S5.   |
|       |                   | (No voluntary anal contraction; no deep anal pressure sensation).     |
+-------+-------------------+-----------------------------------------------------------------------+
| **B** | **Sensory**       | Sensory but NOT motor function is preserved below the neurological    |
|       | **Incomplete**    | level and includes sacral segments S4–S5; no motor function >3 levels |
|       |                   | below the motor level on either side of the body.                     |
+-------+-------------------+-----------------------------------------------------------------------+
| **C** | **Motor**         | Motor function is preserved below the neurological level, and more    |
|       | **Incomplete**    | than half of key muscle functions below the single NLI have a muscle  |
|       |                   | grade less than 3 (Grades 0–2: active movement without gravity).      |
+-------+-------------------+-----------------------------------------------------------------------+
| **D** | **Motor**         | Motor function is preserved below the neurological level, and at least|
|       | **Incomplete**    | half (half or more) of key muscle functions below the single NLI have |
|       |                   | a muscle grade greater than or equal to 3 (movement against gravity). |
+-------+-------------------+-----------------------------------------------------------------------+
| **E** | **Normal**        | Motor and sensory functions are normal across all segments.           |
+-------+-------------------+-----------------------------------------------------------------------+

Incomplete Spinal Cord Injury Clinical Syndromes

Incomplete injuries preserve partial motor and/or sensory pathways below the lesion, yielding distinct clinical syndromes based on the anatomical site of cord damage:

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2. Key Functional Levels and Milestone Matrix

The occupational therapy plan of care is anchored to the client's preserved motor key muscles and dermatomes. Anticipating expected functional outcomes at each neurological level allows therapists to establish realistic, occupation-based goals.

+---------------------------------------------------------------------------------------------------+
|                    SPINAL CORD INJURY FUNCTIONAL MILESTONES & LEVEL MATRIX                        |
+-------+--------------------+----------------------------+-----------------------------------------+
| Level | Key Innervated     | Functional ADL / Mobility  | Essential Adaptive Equipment, Orthoses, |
|       | Musculature        | Expectations               | Seating & Bed Transfers                 |
+-------+--------------------+----------------------------+-----------------------------------------+
| **C1– | C1–C3: Neck muscle | • Dependent in all ADLs/   | • Power wheelchair with chin, head, or  |
|  C3** | (SCM, upper trap). |   transfers.               |   sip-and-puff breath controls.         |
|       | Ventilator-depend. | • Directs 24-hr personal   | • Tilt-in-space / recline power base.   |
|       | C3: Partial        |   care attendants verbally.| • Electronic Aids to Daily Living (EADL)|
|       | diaphragm.         | • Independent power tilt   |   for environmental control/phone.      |
|       |                    |   pressure relief.         | • Mechanical lift (Hoyer) for transfers.|
+-------+--------------------+----------------------------+-----------------------------------------+
| **C4**| Diaphragm, upper   | • Dependent in all ADLs.   | • Power wheelchair with chin/head drive.|
|       | trapezius, levator | • Off ventilator (usually).| • Specialized sip-and-puff EADLs.       |
|       | scapulae (shoulder | • Directs all personal     | • Long straw, cup holder mount.         |
|       | elevation/shrug).  |   care verbally.           | • Mechanical lift for all transfers.    |
+-------+--------------------+----------------------------+-----------------------------------------+
| **C5**| Deltoids, biceps,  | • Feeding/Grooming: Mod    | • Mobile Arm Support (MAS) / suspension.|
|       | brachialis,        |   Assist to setup after    | • Universal cuff, dorsal wrist splint.  |
|       | brachioradialis,   |   setup with adaptive aids.| • Long-handled sponge, angled utensils. |
|       | rhomboids. Active  | • Dressing/Bathing: Total  | • Power wheelchair with joystick/hand   |
|       | shoulder flexion,  |   Assist (UE setup assist).|   controls; manual chair short distances|
|       | abd, elbow flexion.| • Bed mobility/transfers:  |   with plastic/projection handrims.     |
|       | (No elbow ext/     |   Max to Total Assist;     | • Slide board transfer with Max Assist  |
|       |  wrist extension). |   unable to push up.       |   (client lacks triceps).               |
+-------+--------------------+----------------------------+-----------------------------------------+
| **C6**| Extensor carpi     | • Feeding: Mod Indep with  | • Tenodesis splint (wrist-driven flexor |
|       | radialis longus &  |   universal cuff/tenodesis.|   hinge orthosis) or universal cuff.    |
|       | brevis, pronator   | • Grooming: Mod Indep.     | • Button hook, zipper pulls, loop aids. |
|       | teres, clavicular  | • UE Dressing: Mod Indep.  | • Slide board transfers: Mod Indep to   |
|       | pectoralis major.  | • LE Dressing: Min/Mod A.  |   Min Assist on level surfaces.         |
|       | Active WRIST       | • Bed Mobility: Mod Indep. | • Manual wheelchair with quad knobs /   |
|       | EXTENSION present; | • Transfers: Mod Indep     |   friction coated handrims (or power    |
|       | tenodesis grasp!   |   level slide board.       |   wheelchair for community distances).  |
+-------+--------------------+----------------------------+-----------------------------------------+
| **C7**| Triceps, latissimus| • Feeding/Grooming: Indep. | • Standard utensils, reacher, dressing  |
|       | dorsi, wrist       | • UE Dressing: Indep.      |   stick, sock aid, long-handled sponge. |
|       | flexors, finger    | • LE Dressing: Mod Indep   | • Independent depression transfers      |
|       | extensors. Active  |   with adaptive devices.   |   WITHOUT a slide board.                |
|       | ELBOW EXTENSION!   | • Bed Mobility: Indep.     | • Manual wheelchair: Independent indoor |
|       |                    | • Transfers: Indep depres- |   and outdoor community propulsion;     |
|       |                    |   sion transfers (no board)|   transfers wheelchair in/out of car.   |
+-------+--------------------+----------------------------+-----------------------------------------+
| **C8– | Flexor digitorum   | • All ADLs: Independent /  | • Standard writing & dining utensils.   |
|  T1** | profundus/superfic,|   Modified Independent.    | • No specialized adaptive splints needed|
|       | thenar/hypothenar, | • Independent manual       |   for upper extremity feeding/grooming. |
|       | interossei, thumb  |   wheelchair propulsion.   | • Independent manual wheelchair curb    |
|       | add. FULL HAND     | • Independent car transfer |   management and wheelies.              |
|       | INTRINSICS & GRIP! |   and chair breakdown.     | • Modified independent bowel/bladder.   |
+-------+--------------------+----------------------------+-----------------------------------------+
| **T1– | Intercostals,      | • Independent in all ADLs, | • Standard manual wheelchair.           |
|  T6** | upper back exten-  |   IADLs, transfers, and    | • Standing frame / tilt table for bone  |
|       | sors. Upper trunk  |   manual wheelchair.       |   density and circulation.              |
|       | stability intact.  | • Vulnerable to Autonomic  | • Full independent living with home     |
|       |                    |   Dysreflexia (T6 & above)!|   modifications.                        |
+-------+--------------------+----------------------------+-----------------------------------------+
| **T7– | Full abdominal &   | • Independent in all self- | • Manual wheelchair independence in all |
| T12** | intercostal control|   care and home management.|   terrains; wheelchair athletic sports. |
|       | Lower trunk balance| • Effective, strong cough. | • Ambulation: Functional ambulation with|
|       | & stable core.     | • Standing frame/bracing.  |   KAFOs/crutches (exercise ambulation). |
+-------+--------------------+----------------------------+-----------------------------------------+
| **L1– | Hip flexors (L2),  | • Independent in all ADLs/ | • Ambulation: Household to community    |
|  S5** | quadriceps (L3),   |   IADLs and transfers.     |   ambulation with AFOs, KAFOs, canes, or|
|       | dorsiflexors (L4), | • Functional community     |   crutches. Wheelchair used for long    |
|       | plantarflex (S1).  |   ambulation with orthoses.|   community distances if needed.        |
+-------+--------------------+----------------------------+-----------------------------------------+

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3. Tenodesis Grasp Biomechanics & Preservation Rules

The preservation and functional optimization of the tenodesis grasp is one of the most critical rehabilitation objectives for clients with a C6 spinal cord injury.

Biomechanical Mechanism of Tenodesis

Tenodesis action relies on passive tension generated across multi-joint tendons:

• When the wrist active extends (innervated extensor carpi radialis longus/brevis, C6), tension in the passive long finger flexors (flexor digitorum profundus and flexor digitorum superficialis) pulls the fingers into passive flexion, creating a functional palmar grasp or lateral pinch.
• When the wrist passively flexes, tension in the long finger extensors causes the fingers to passively open/extend, releasing the held object.

+---------------------------------------------------------------------------------------------------+
|                         TENODESIS PRESERVATION & BIOMECHANICAL RULES                              |
+---------------------------------------------------------------------------------------------------+
| RULE 1: NEVER STRETCH FINGER FLEXORS WITH WRIST EXTENSION                                         |
|   • Allowing the long finger flexors to elongate destroys passive tenodesis tension.              |
|   • When ranging finger extension, the therapist MUST keep the wrist in FLEXION.                  |
|                                                                                                   |
| RULE 2: PROM PROTOCOL FOR TENODESIS PRESERVATION                                                  |
|   • Wrist Extension Range: Range wrist extension ONLY with fingers and thumb FULLY FLEXED.        |
|   • Finger Extension Range: Range finger extension ONLY with the wrist in FULL FLEXION.           |
|                                                                                                   |
| RULE 3: ADAPTIVE PROSTHETICS & SPLINTING                                                          |
|   • Tenodesis Splint (Wrist-Driven Flexor Hinge Orthosis): Mechanically couples active wrist      |
|     extension to drive index/middle fingers into solid 3-point pinch against the thumb.          |
|   • Short Opponens / C-Bar Splint: Maintains first web space to prevent adduction contracture.    |
|                                                                                                   |
| RULE 4: FUNCTIONAL BED TRANSFERS & WEIGHT-BEARING POSITIONING                                     |
|   • During slide board transfers or weight-bearing push-ups, the client MUST bear weight on       |
|     FLAT PALMS WITH FINGERS FLEXED (curled into a loose fist) or on FISTS, NEVER on flat extended |
|     fingers with extended wrists!                                                                 |
+---------------------------------------------------------------------------------------------------+

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4. Critical Medical Emergencies in Spinal Cord Injury

Occupational therapists must immediately identify and manage three primary life-threatening or debilitating medical complications: Autonomic Dysreflexia, Orthostatic Hypotension, and Heterotopic Ossification.

1. Autonomic Dysreflexia (Hyperreflexia)

Autonomic Dysreflexia (AD) is an acute, life-threatening medical emergency occurring in individuals with spinal cord injuries at T6 and above. It is triggered by an uninhibited, massive sympathetic nervous system discharge provoked by a noxious visceral or cutaneous stimulus below the neurological injury level.

+---------------------------------------------------------------------------------------------------+
|                                AUTONOMIC DYSREFLEXIA (T6 AND ABOVE)                               |
+-------------------------------------------------+-------------------------------------------------+
| PATHOPHYSIOLOGY & ETIOLOGY                      | CLINICAL MANIFESTATIONS & SYMPTOMS              |
+-------------------------------------------------+-------------------------------------------------+
| • Noxious stimulus below T6 triggers massive    | • Sudden, severe, pounding arterial headache    |
|   sympathetic surge (vasoconstriction).         | • Paroxysmal hypertension (systolic BP          |
| • Descending inhibitory brainstem signals are   |   elevates 20–40 mmHg above baseline)           |
|   blocked by the spinal cord lesion.            | • Bradycardia (vagal compensatory baroreflex)   |
| • Compensatory vagus nerve parasympathetic      | • Profuse sweating & flushing ABOVE the lesion  |
|   response produces vasodilation ABOVE lesion.  | • Red blotching of skin, nasal congestion       |
| • Common Triggers: Distended bladder / blocked  | • Pale, cold, clammy skin & piloerection        |
|   catheter (>80%), fecal impaction, pressure    |   (goosebumps) BELOW the lesion                 |
|   sore, ingrown toenail, tight clothes/straps.  | • Blurred vision, severe anxiety, restlessness  |
+-------------------------------------------------+-------------------------------------------------+

+---------------------------------------------------------------------------------------------------+
|                       STEP-BY-STEP AD EMERGENCY PROTOCOL (ACTION SEQUENCE)                        |
+---------------------------------------------------------------------------------------------------+
| STEP 1: IMMEDIATELY SIT THE CLIENT FULLY UPRIGHT (90 DEGREES)                                     |
|         • Gravitational pooling of blood in lower extremities reduces intracranial blood pressure.|
|         • CRITICAL CONTRAINDICATION: NEVER LAY THE PATIENT FLAT! Supine positioning further raises|
|           cerebral arterial pressure, risking hemorrhagic stroke, seizure, or death.              |
|                                                                                                   |
| STEP 2: LOOSEN ALL RESTRICTIVE CLOTHING & CONSTRICTIVE DEVICES                                    |
|         • Unfasten tight belts, abdominal binders, compression stockings (TED hose), and shoes.   |
|                                                                                                   |
| STEP 3: CHECK & RELIEVE URINARY BLADDER / DRAINAGE SYSTEM                                         |
|         • Check Foley catheter tubing for kinks, twists, or bag overfilling.                      |
|         • If uncatheterized, perform immediate straight catheterization to decompress bladder.    |
|                                                                                                   |
| STEP 4: CHECK BOWEL & SKIN FOR NOXIOUS IRRITANTS                                                  |
|         • Check for fecal impaction (instill topical lidocaine jelly prior to digital check).     |
|         • Inspect skin for sharp objects, pressure points, tight leg bag straps, or burns.        |
|                                                                                                   |
| STEP 5: NOTIFY NURSING & MEDICAL STAFF IMMEDIATELY                                                |
|         • Continuously monitor vitals every 2–5 minutes; prepare for emergency pharmacological    |
|           intervention (e.g., Nitropaste, nifedipine) if systolic pressure remains elevated.      |
+---------------------------------------------------------------------------------------------------+

2. Orthostatic Hypotension (Postural Hypotension)

• Pathophysiology: A sudden drop in arterial blood pressure (systolic drop ≥ 20 mmHg or diastolic drop ≥ 10 mmHg) upon moving from supine to upright/seated positions. Caused by loss of sympathetic vasoconstrictor tone and muscular pump failure in lower extremities and splanchnic vascular bed.
• Signs & Symptoms: Dizziness, lightheadedness, pallor, blurred vision, diaphoresis, nausea, syncope (loss of consciousness).
• Immediate Occupational Therapy Protocol:
  1. Immediately recline the wheelchair or lower the head of the bed, elevating the client's lower extremities above heart level until blood pressure stabilizes and symptoms resolve.
  2. Preventative Measures: Apply abdominal binders and elastic compression stockings (TED hose) prior to sitting upright; use a tilt-in-space wheelchair or tilt table for gradual vertical progression; ensure adequate hydration.

3. Heterotopic Ossification (HO)

• Pathophysiology: Ectopic formation of true lamellar bone within periarticular connective tissue and soft musculature surrounding large joints (most frequently the hip, followed by knee, elbow, and shoulder), typically presenting 1 to 4 months post-injury.
• Signs & Symptoms: Localized joint warmth, erythema, periarticular edema, rapid progressive loss of active/passive range of motion, low-grade fever, and localized pain or autonomic response.
• Management & Precautions:
  • Gentle, pain-free active and active-assisted ROM within available joint tolerance.
  • STRICT CONTRAINDICATION: Forceful, aggressive, or ballistic stretching, which causes intramuscular microtrauma, tissue tearing, hemorrhage, and dramatically accelerates ectopic bone growth.
  • Prompt notification of physician for diagnostic imaging (triple-phase bone scan, plain radiography) and pharmacological management (NSAIDs like indomethacin, bisphosphonates, or surgical resection once mature).

4. Pressure Injury Prevention & Cushion Selection

• Weight Shift Schedules: Seated pressure relief must occur every 15 to 30 minutes for a duration of 30 to 60 seconds.
• Methods: Power tilt-in-space (minimum 45° tilt required for significant sacral and ischial pressure reduction), depression push-ups (C7 and below), or forward/lateral lean (C6 and above).
• Skin Inspection: Perform visual skin inspection twice daily using a long-handled mirror to inspect the sacrum, ischial tuberosities, greater trochanters, and heels.
• Cushion Prescription: Specialized dynamic air flotation (e.g., Roho), contoured viscous fluid/gel (e.g., Jay), or hybrid honeycomb matrices to distribute peak ischial pressures.