Tone Abnormalities and Motion Restrictions (week 1)

Muscle Tone

is the underlying tension in a muscle that serves as a background for contraction.

is the stiffness or slackness of a muscle. Tone can change due to normally physiological changes or due to pathology

is assessed as the resistance to passive motion (no active resistance to the muscle stretch).

What cause muscle to have tone?

Neural inputs from the periphery, spinal cord and supraspinal brain centers all contribute to muscle activation.

Causes of muscle tone abnormalities

Muscle tone is predominantly created by input from the PNS and the CNS.

Abnormalities in the peripheral, spinal or supraspinal neurons can result in hypertonicity or hypotonicity

Stiffness of the muscle and surrounding connective tissue can also affect muscle tone.

Hypotonicity

decreased resistance to stretch compared to normal muscles.

Flaccidity means a total lack of tone or the absence of resistance to stretch within the middle range of the muscle’s length

Hypertonicity

an increased resistance to stretch compared with normal muscles.

Rigidity is an abnormal hypertonic state in which muscles are stiff or immovable and resistant to stretch regardless of velocity

Spasticity

velocity-dependent resistance to stretch, with resistance increasing when the stretch occurs at higher velocities

Clonus

A term used to describe multiple rhythmic oscillations or beats of involuntary muscle contractions in response to a quick stretch.

Tone and Physical Agents

Physical Agents can be used to facilitate an increase or decrease in muscle tone.

When assessing the current status of a patient prior to the application of a physical agent, you need to be aware of tone abnormalities.

Changes in tone may be cause for continuing or discontinuing a treatment.

Assessing tone will be discussed further in your Neuro courses.

Physical Agents used to Increase Muscle Tone

Electrotherapy, hydrotherapy and quick ice can be used to increase muscle tone.

Physical Agents used to Decrease Muscle Tone

Physical agents selection is based on the cause of the increased tone:

• Pain, cold, stress —> Modalities that reduce pain, warm the patient, stimulation of antagonist

• Spinal cord injury —> Heat or prolonged ice

• Cerebral lesions —> Prolonged ice, CPM, Hydrotherapy

• Rigidity —> Heat

Passive Motion Restrictions

Soft tissue shortening

Mechanical block

Spinal disc herniation

Adverse Neural Tension

Edema

Adhesion

Active Motion Restrictions

Muscle weakness

Abnormal muscle tone

Pain originating from the musculotendinous unit or other local structure

Restrictions in passive ROM

Inability or unwillingness of patient

Contractile

Muscle

Musculotendinous junction

Tendon

Tendinous interface with bone

WILL MOST LIKELY JUST DECREASE AROM

Noncontractile

Skin

Ligament

Bursa

Capsule

Articular cartilage

Intervertebral disc

Peripheral nerve

WILL DECREASE AROM AND PROM