The general purpose of this research project is to use surface electromyography to compare
the effect of Active Release Technique versus Proprioceptive Neuromuscular Facilitation on
the electrical activity of the upper trapezius muscle at rest and during contraction.
Both ART and PNF are soft tissue techniques used to decrease muscle hypertonicity, myospasm,
and/or trigger points and increase the overall function of muscles.
Active-release technique, or ART®, is a form of myofascial therapy used in pain management
that involves soft-tissue manipulation. ART has the expressed goal of restoring optimal
texture, motion, and function of the soft tissue while releasing entrapped nerves or blood
vessels. An injury to a soft-tissue structure commonly causes the muscle to shorten to
guard or protect the area. A clinician who is performing ART makes a soft contact with one
hand on the patient just distal to the injured area while the other hand develops tension on
the soft tissue. While the contact tension is maintained, the structure is lengthened using
an "active motion." During the motion, the lesion is palpated and the physical contact with
the patient is changed or moved slightly in order to concentrate the tension in the
appropriate tissue (Swann, et al).
Active Release Technique was developed by Dr. Michael Leahy and is widely used in
rehabilitative and sports medicine for myofacial pain syndromes. The ART group will be
treated by one investigator in concurrence with treatment methods outlined in Dr. Leahy's
ART instructional manual. An ART treatment pass involves taking the tissue from a shortened
position to a lengthened position while the administer maintains manual contact. We will
perform three passes of ART with a 10 second rest period between passes. We will only
perform ART on the symptomatic side (side that fits inclusion criteria); if both sides are
involved, each side will be considered as a separate analysis.
The research backing ART is inadequate. Although there are numerous testimonials, limited
published research studies could be found. Dr. George's study of the effect of ART, HVLA
and no treatment on the temporomandibular joint and masticatory muscles showed no
significant difference between the pre- and post-treatment mouth opening measurements.
Another ART study of lateral epicondylitis concluded that the technique was successful in
removing adhesions and promoting restoration of normal tissue but also stated that research
was inadequate (Howitt, et al). A carpal tunnel study completed in 2006 used EMG to measure
the effectiveness of ART. There were significant improvement in symptom severity and
functional status after treatment, but no significant differences found in the EMG analyses
(George, Tepe, and Busold 119-122).
Proprioceptive neuromuscular facilitation (PNF) stretching techniques are commonly used in
the athletic and clinical environments to enhance both active and passive range of motion
(ROM) with a view to optimizing motor performance and rehabilitation by elongating the
muscle (Sharman, et al).
A second investigator will perform all the PNF using the published protocol from Warren
Hammer, DC, MS, DABCO, in the text Functional Soft Tissue Examination and Treatment by
Manual Methods, which is as follows:
The patient is supine with the examiner supporting the head so that the neck is in
contralateral sidebending and ipsilateral rotation and flexion. The whole cervical spine
and occiput is fixed and held in long-axis traction. With the other hand, the examiner
contacts the shoulder with the forearm parallel to the table and pushes inferiorly to
determine end feel. While maintaining the above position, the examiner asks the patient to
resist by pushing the shoulder superiorly against the examiner's resistance for 7 seconds.
The examiner then asks the patient to let go and, while stabilizing the head and neck,
depresses the shoulder as far as possible for 12 seconds.
A previous study of PNF concluded that the technique caused short-term deficits in strength,
power output, and muscle activation; it also increased ranges of motion (Marek, et al). A
second previous study concluded that PNF caused an increase in electromyographic activity of
the masticatory muscles (Olivo, et al).
Surface EMG is a reliable, non-invasive tool used for measuring muscular electrical
activity. Electromyography (EMG) can provide unique information about the mechanical and
motor control strategies during various types of muscle actions. EMG measures muscle
activation, with surface EMG reflecting the algebraic sum of electric muscle action
potentials that pass within the recording areas of the EMG electrodes. There, EMG amplitude
quantifies muscle activation, which can be altered by the number of motor units recruited
and the firing rates of the activated motor units. Thus, decreases in EMG amplitude due to
decreases in muscle activation (Marek, et al). The surface EMG protocol will be performed
completely by a third investigator.
Farina, et al published an article showing that the EMG can give reliable indications of
muscle activity and fatigue. A previous study of muscle activity using surface EMG noted
that based on visual inspections, all surface EMG variables showed consistent linear to
moderately curvilinear behavior as a function of time (Muhammed, et al). Surface EMG has
been widely used and accepted however care must be taken in pad placement as incorrect
placement will give readings of improper musculature, as concluded in a study by Susan
- Not all of the below listed criteria must be present, but some combination of two or
more should be present before the participant can be deemed to have hypertonic
- hypertonic levator scapulae musculature.
- Anterior head carriage
- Internally rolled shoulders
- Occupational risk of poor upper cross posture
- Palpable muscular tightness
- Tenderness to palpation of the area
- Participant complaint of pain or tightness in the area
- Participants will be excluded from this study if they have a history of a trauma that
lead to marked scar tissue in the upper trapezius muscle as this would alter the
surface EMG readings due to injured and altered tissue.