Muscle Energy

Muscle energy is a direct, active technique. Direct means that the physician's motion is applied towards the restrictive barrier, and active means that there is participant involvement.

General steps:

Assess for somatic dysfunction

• T4 F Rr Sr

The physician places the patient towards the opposite of the somatic dysfunction (direct) until restriction is felt.

• T4 F Rr Sr
  • Physician places patient T4 E Rl Sl

The patient is then instructed to contract against the physician's force (active). The physician places an equal counterforce without actual movement (isometric contraction) for 3-5 seconds.

• T4 F Rr Sr
  • Physician places patient T4 E Rl Sl
  • Patient moves T4 F Rr Sr for 3-5 seconds
    • The physician resists their force

The patient is then asked to relax completely, and the physician moves the patient further into the new barrier.

• T4 F Rr Sr
  • Physician places patient T4 E Rl Sl
  • Patient moves T4 F Rr Sr for 3-5 seconds
    • The physician resists their force
  • Patient relaxes while the physician moves T4 further into the new barrier of extension, left rotation, and left sidebending.

This cycle of contraction and relaxation is repeated 3-5 times until no further improvement is felt.

After no more improvements are felt, the patient is reassessed to check for improved range of motion and resolution of the dysfunction.

Neurophysiological Theory

Muscle Spindle and Alpha Motor Neuron Function

The muscle spindle serves as a specialized proprioceptive receptor within skeletal muscles, detecting changes in muscle length and the rate of change. Understanding its function is crucial to comprehending how the muscle energy technique works:

Structure and Function:

• Contains intrafusal fibers (innervated by gamma motor neurons)
• Surrounded by extrafusal fibers (innervated by alpha motor neurons)
• When stretched, it sends signals via Group Ia and II afferent fibers to the spinal cord

Protective Mechanisms:

• Muscle stretch activates the spindle, causing the stretched muscle to contract (stretch reflex via alpha motor neuron activation)
• Simultaneously causes the antagonist muscle to relax (reciprocal inhibition)
• Gamma motor neurons maintain intrafusal fiber sensitivity even during muscle contraction

When a muscle contracts via alpha motor neurons, it would shorten and make the spindle "slack," which would reduce its ability to detect stretch. Gamma motor neurons contract the intrafusal fibers, keeping the spindle taut even during muscle contraction, maintaining its sensitivity to stretch.

The Challenge and Solution

The Problem: When treating tight or dysfunctional muscles, attempted stretching would normally trigger the muscle spindle's protective response, preventing effective treatment.

The Solution: This is where the Golgi tendon organ (GTO) becomes essential. The GTO detects changes in muscle tension and, when activated, causes inhibition of the same muscle (autogenic inhibition).

Why Golgi Tendon Organs Matter

GTOs serve several critical functions:

Protection: Inhibits muscle contraction when tension becomes dangerously high, protecting tendons and muscle fibers from rupture.

Movement Quality: Allow muscles to release gradually after contraction, preventing jerky or unsafe movements.

Load Adaptation: Provide feedback to help the central nervous system assess and adjust force application for activities like walking, climbing, and carrying.

Application in Muscle Energy Technique

Isometric Contraction Strategy:

• Isometric contraction increases both GTO and muscle spindle activity
• Keeping the muscle at the same length limits muscle spindle activation while maximizing GTO activation
• This approach minimizes the stretch reflex while engaging the inhibitory response

Post-Contraction Benefits: After isometric contraction, there's a brief period of reduced alpha motor neuron excitability due to:

• Autogenic inhibition: GTO activation inhibits alpha motor neuron firing
• Decreased spindle sensitivity: Temporarily reduces stretch reflex activity

This neurological "quiet period" allows physicians to stretch the muscle more effectively into new ranges without encountering reflex resistance.

Role in Muscle Energy Technique

1. Isometric contraction of the muscle causes an increase in Golgi tendon organ and muscle spindle activity.
   1. Isometric as to limit the activation of the muscle spindle while activating the Golgi tendon organ
      1. Remember that the muscle spindle is sensitive to changes in muscle length and rate of length change. While there will always be a little activation on initial movement, this can be limited by keeping the muscle the same length.
2. After the contraction, there is a brief period of reduced excitability of the alpha motor neuron - this is due to:
   • Autogenic inhibition: Activation of Golgi tendon organs inhibits alpha motor neuron firing to the contracting muscle.
   • Decreased spindle sensitivity: Briefly lowers stretch reflex activity.
3. This neurologic "quieting" allows the physician to stretch the muscle more effectively into a new range without reflex resistance.

Types of Muscle Energy Techniques

1. Crossed Extensor Reflex

Concept: Apply muscle force to the contralateral (opposite) side to relax the targeted muscle on the ipsilateral (same) side.

Application: Particularly beneficial when extremities are injured and cannot undergo direct manipulation.

Example: When treating right triceps dysfunction, the patient contracts the left triceps, creating a reflexive relaxation response in the problematic right triceps.

2. Joint Mobilization

Concept: Restore joint range of motion through controlled muscle contractions applied at the restrictive barrier.

Example: For anterior innominate somatic dysfunction, contracting the hamstrings allows the innominate bones to rotate posteriorly, gradually restoring normal pelvic mechanics.

3. Oculocephalogryic Reflex

Concept: Utilize the connection between eye movements and spinal muscle activity to address cervical and upper thoracic restrictions.

Application: Patients use specific eye movements to engage cervical and upper thoracic muscles, helping relax antagonistic muscles. Eye direction depends on the therapeutic goal—toward or away from the restriction.

Example: For occipitoatlantal joint dysfunction, patients look up for extension dysfunction or down for flexion dysfunction, creating the appropriate neurological response.

4. Post-Isometric Relaxation

Concept: Engage all planes of the restrictive barrier simultaneously, with the patient initially contracting away from the barrier while the physician maintains counterforce.

Application: Particularly effective for subacute or chronic conditions, as the dysfunctional muscle is directly engaged.

Example: For posterior radial head somatic dysfunction:

• Position the forearm in supination (into the restrictive barrier)
• Patient actively pronates (away from barrier) while physician applies counterforce
• Repeat until achieving favorable range of motion improvement

5. Reciprocal Inhibition

Concept: When an antagonist muscle contracts, it signals the spinal cord through the reciprocal reflex arc, forcing the agonist muscle to relax.

Application: Most effective in acute conditions, as minimal strain is placed on the dysfunctional muscle.

Example: For hypertonic biceps, contract the triceps (antagonist) to neurologically promote biceps relaxation.

6. Respiratory Assistance

Concept: Use voluntary deep breathing to restore normal motion in restricted areas.

Application: Particularly valuable for addressing rib somatic dysfunction.

Example: For inhaled ribs 7-10, where anterior and lateral rib motion becomes restricted during inhalation, exaggerated sidebending during exhalation utilizes natural respiratory mechanics to restore proper rib function and mobility.