FASTA: Flexibility and Strength Training in Asthma

The treatment of symptomatic asthma currently focuses on the use of medications - inhaled or systemic - that have the principal goals of relieving airway pathology, namely airway narrowing, inflammation, mucus metaplasia and hyper-reactivity. There are no therapies directed at the chest wall or its connective tissue structural units, including connective tissue matrix, bone health and chest wall musculature. Resistive flexibility and strength training (RFST) is a new physical therapy technique that has successfully addressed abnormalities in the upper and lower extremities and back. In this application, we propose to use internal funding for a pilot project to explore the potential holistic benefits of RFST directed to the chest wall in symptomatic asthmatics as well as the potential mechanical basis of its therapeutic benefits if observed.

In RFST, the practitioner extends or flexes a joint, while the patient actively resists the motion applied by the practitioner. In other words, the patient performs an eccentric contraction of extensor muscles if the joint is flexed, or of flexor muscles if the joint is extended. The technique is based on the following theoretical principles:

• Opposing muscle pairs (i.e. ipsilateral flexor/extensor) can become dysfunctional when connective tissue within one of the muscles (either the flexor or the extensor) becomes chronically shortened-thought to be due to long-standing exaggerated centrally driven tonic muscle activity either following an injury or due to posture habit. When this happens, connective tissue within the opposing muscle will become chronically lengthened due to shortening of the paired muscle.
• The connective tissue can become inelastic and restrictive resulting in the muscles being held in a chronically short or lengthened position. These positions can change.
• In the trunk, imbalances can occur between flexor/extensor groups (e.g. psoas/multifidus) and also between right/left muscle pairs, creating postural asymmetries. For example, shortening of the psoas muscle on one side will lead to lengthening of the psoas on the contralateral side.
• Shortening of limb girdle muscles (e.g. pectoralis, gluteus) can create complex imbalance patterns both across local flexor/extensor pairs, across sides, and diagonally across the trunk (e.g. shortening of pectoralis major on one side causing lengthening of extensor muscles in contralateral hip).
• The end result of these imbalances is that the shortened muscles restrict the range of movement, and the lengthened muscles cannot function optimally in a lengthened position.

It is thought that resistance stretching 1) allows the shortened muscles to lengthen and the lengthened muscles to shorten by remodeling intramuscular and perimuscular connective tissue, 2) allows lengthened muscles to contract at a more favorable length and 3) allows for an increase in flexion, extension, and flexibility through joint ranges of motion.