Oscillation involves rapidly alternating directions of motion over very short amplitudes. Amplitude, intensity, frequency, and method of application can be modulated to deliver an engaging series of exercises for facilitating muscle activation and coordination of movement. Several oscillating tools can be used to facilitate muscle activation. For example, oscillation with a Flexbar can activate muscles in the entire upper quarter (see figure 10.2; Page et al. 2004).
Brushing and Tapping
Brushing has been advocated by Rood to facilitate the spindle via the anterior horn cell and gamma loop (Carr and Shepherd 1980). Local or generalized brushing may be performed manually or electrically and may improve muscle activity as well as the patient’s perception and experience of the muscle group or segment. Brushing the bottom of the foot may stimulate proprioceptors in the sole to increase the amount of afferent information (figure 10.3). Tapping over the muscle belly can be facilitatory, as it promotes localized quick stretching of the muscle fibers that enhances the myotatic reflex and therefore the contractility of the muscle.
Drop and Catch
Drop and catch is basically a quick stretch technique to facilitate the muscle spindle and muscle contraction via the myotatic reflex. It must be used with good control of all involved segments by the therapist and a short amplitude of application to minimize injury risk. It may be useful for an aberrant movement pattern of a segment or an inhibited muscle or muscle group. The inhibited muscle group is shortened passively and then placed in a supported static position. The clinician explains to the patient that at a randomly selected moment the support will be removed. The patient must initiate a rapid active contraction to prevent the segment
from dropping uncontrollably out of the assumed position. This sequence is repeated 5 or 6 times. The drop and catch technique is often preceded just before by rubbing, tapping, or vibrating the involved muscle and its overlying skin for several seconds. It is best suited to large muscle groups and more robust joints such as the hip, knee, or elbow (see figure 10.4).
Acupuncture and Dry Needling
Given the high correlation between acupuncture points and TrPs (Melzack, Stillwell, and Fox 1977), using acupuncture needles to dry needle into the motor points and TrPs of muscles is very effective in eliminating TrPs or tender points that affect muscle contraction and performance (Hong 1994; Jaeger and Skootsky 1987). In addition to providing central analgesic effects (Hsieh et al. 2001), the stimulation of acupuncture points affects the limbic system and subcortical gray structures of the brain (Hui and Lui 2000), thereby influencing muscle tone throughout the motor system. This influence can aid in the normalization of ROM and muscle function.
In their book Biomedical Acupuncture for Pain Management: An Integrative Approach, Ma, Ma, and Cho (2005) provide a logical and structured approach to the dry needling of palpable tender points (that may include TrPs). Dry needling can improve motor function and modulate pain locally and centrally, among other things. The evaluative process and treatment differs significantly from those of traditional Chinese medicine in that the choice of points is determined by palpable tenderness in specific anatomical locations and is not related to meridians or the attributes traditionally assigned to them. Also, no herbs are recommended or administered as part of the treatment. Dry needling can be performed three times a week or more in conjunction with other therapies. Reassessment after each session determines the need for subsequent treatments. Unfortunately dry needling is not an option for many physical therapists, although it should be.
Proprioceptive Neuromuscular Facilitation
Proprioceptive neuromuscular facilitation (PNF), developed by Kabat (1950) and Knott and Vossin the 1950s, has provided a useful basis for facilitating and guiding movement synergies that reflect natural components of gross motor function and development while at the same time inhibit unwanted hypertonicity and hypotonicity. With the use of maximum available resistance, quick stretches, spiral and diagonal patterns, and rhythmic and combined motions, PNF restores and improves motor control and movement perception in patients. Exposing the CNS to familiar synergistic movement components can guide the therapist in choosing appropriate movements and emphasis. In chronic pain situations in which altered movement and degraded quality of movement may be a limiting factor, PNF can serve as an entry portal for change.
Origin–insertion facilitation, introduced by G. Goodheart in 1964 (Goodheart Jr. 1964; Walther 1988), led to the development of applied kinesiology and eventually clinical kinesiology. It focuses on the indirect facilitation of a neurologically inhibited muscle via the anterior horn. Facilitation is achieved by manually stimulating receptors and nerve endings as well as cutaneous receptors located at the origin and insertion of muscles. The suspected muscle is isolated as much as possible via positioning and is tested with a patient-initiated MMT. The practitioner observes the muscle’s ability to contract isometrically on command; any sign of lag or give during the initial 2 to 3 s of the test is interpreted as neural incoordination and a sign of inhibition—in other words, hyperpolarization of the motor neuron. The origin and insertion of the muscle are then massaged for several seconds, and the muscle is reevaluated for an improvement in its ability to contract swiftly and effectively and to stabilize the assumed position isometrically without lag or give. This technique is suitable for many muscles, large or small, and can be very effective in improving muscle contractility and strength output (Walther 2000).
Muscle testing, origin–insertion manual therapy, and isometrics are also important aspects of the muscle activation techniques (MAT) developed by Greg Roskopf. However, the evaluative premise and thought process for MAT differ significantly from those of applied kinesiology. MAT is a system of biomechanical evaluation and treatment designed to address muscle imbalances and to restore agonist–antagonist balance. It includes a joint-specific ROM exam and the assessment of weakness and inhibition of correlated positional muscles. This approach to muscle activation is an important and basic aspect of the initial rehabilitation phase.
All muscles under voluntary control must be able to contract sufficiently and within sufficient time to maintain a direct relationship to the imposed load and speed of loading in order to satisfy the demands of any required task. If this basic criterion cannot be met, strengthening exercises will not be as effective. The Web site www.muscleactivation.com can furnish the reader with more information.