1. Tone Abnormalities
Chapter 4

2. Muscle Tone
Definition (page 77) – underlying tension in the muscle that serve as a background for contraction.
Muscle tone include involuntary resistance generated by neurally activated fibers and passive, natural biomechanical tension in connective tissue.

3. Normal mm tone and activation depends on normal functioning of muscle, the PNS, and the CNS.

4. Description of Muscle Tone
Muscle tone can be described as “low tone” or “high tone”.
Tone can be palpated as a qualitative difference in the resistance to finger pressure over a muscle.

5. Low Tone
Upon palpation the finger will sink into the mm with little resistance.

6. High Tone
Upon palpation the muscle feels hard and resists deformation

7. Tone Abnormalities

8. Hypotonicity
Low tone
Decreased resistance to stretch compared with normal muscles.
FLACCIDITY is a type of low tone. It is a total lack of tone or the absence of tone.

9. HYPERTONICITY
High tone or increased resistance to stretch compared with normal muscles.
Can be either RIGID of SPASTIC

10. Rigidity
Abnormal, hypertonic state in which muscles are stiff or immovable and resistant to stretch.
This type of tone is common in Parkinson’s disease

11. Spasticity This is different than a muscle spasm
Velocity-dependent resistance to stretch.
See table 4-1, page 79

12. Role Physical Agents with Tone Abnormalities

13. Physical Agents and Hypotonicity
Rehab interventions are directed to increasing tone to promote easier activation of muscles.
Physical agents may be used to assist with muscle activation.
Hydrotherapy
Quick ice
Electrical Stimulation

14. Physical Agents and Hypertonicity
Rehab interventions directed to decreasing tone to decrease discomfort, increase ROM, allow normal positioning, and prevent contractures.
Physical agents may be used to assist with decreasing tone.
Heat
Prolonged ice
Hydrotherapy
Biofeedback
Electrical Stimulation