Overview
Assessment of tone is the first part of the motor assessment, and is a good starting point and screening tool in that abnormal tone can immediately suggest an upper motor neuron lesion or Parkinsonism.
How to Assess
- Ask the patient to relax and allow you to move their arms. Move the wrists and elbows passively through their range of motion, assessing for rigidity.
Interpretation
- Increased: resistance to passive movementUpper motor neuron lesion
- Normal: minimal resistance
- Decreased: no resistanceLower motor neuron or cerebellar lesion
Spasticity
Spasticity, or clasp-knife rigidity, is a velocity-dependent increase in tone seen with rapid flexion or extension of a joint.
How to Assess
- Rapidly flex or extend the elbow or knee joint, assessing for a sudden increase in resistance.
Significance
- Suggests the presence of an upper motor neuron lesion.
Lead Pipe Rigidity
Feel For
- A continuous and non-velocity dependent increase in tone. This is best assessed at the elbow, wrist and knee joints.
Significance
- Caused by Parkinson's disease, other causes of parkinsonism, and contractures.
Cog Wheel Rigidity
Feel For
- Rigidity associated with tremor, resulting in jerky start / stop movement of the joint.
Significance
- Caused by Parkinson's disease, other causes of parkinsonism, and contractures.
Next Page
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------