Immersion: Motor exam

To assess the motor system, test the strength in each major muscle group as demonstrated in the video above. Motor strength and bulk are compared side to side, and strength is graded on a 0-5 scale.    Functional testing with heel and toe walking is an alternative method of testing strength in the legs.

Test each of the following muscle groups, stabilizing above the joint with one hand and comparing side to side.

Upper extremity:

• Shoulder abductors
• Arm flexors and extensors (biceps and triceps)
• Wrist flexors and extensors
• Finger flexors and finger abductors

Lower extremity:

• Hip flexors, extensors, abductors and adductors
• Knee flexors and extensors
• Foot dorsiflexors and plantar flexors

Weakness can be a finding of central or peripheral motor neuron disease or disorders of the neuromuscular junction or muscle. Atrophy suggests disuse of the muscle or lower motor neuron disease.

Pronator drift is a subtle sign of arm weakness.  The patient is asked to hold their arms out, with palms up, and eyes closed.  If one arm is weak, it will ‘drift’ into pronation, with the palm turning down