Objectives:
The diaphragm is the primary muscle of inspiration and provides life sustaining oxygen to the body (Voyvoda et al, 2011). It is active during relaxed and effort induced ventilation.
Diaphragm contraction results in pressure changes within the thorax thereby assisting in
airflow into the lungs and increasing lung volumes. During this inhalation process the
diaphragm moves from a dome-shaped relaxed position into a flattened shortened position.Often during the increased work of breathing in patients suffering from chronic obstructive pulmonary disease (COPD), the diaphragm does not sit in its anatomical resting position; it shortens and weakens (Watson et al, 2001). Stretching of skeletal muscles is a physiotherapy treatment modality commonly used in clinical practice. The aim of this treatment modality is to increase the length of a shortened muscle thereby improving the range of motion of said muscle and improving the specific joint motion (Wepler and Magnusson, 2011). Head down tilt positions are commonly used in cardiopulmonary physiotherapy to utilise gravity to facilitate sputum drainage from different lung segments (Pryor & Prasad, 2008; Selsby & Jones, 1990). A head down tilt position could potentially have an influence on diaphragm length if applied for a sustained period of time due to likely abdominal content displacement from a caudal to cranial position resulting in a stretch on the diaphragm.
The objective was to determine if diaphragm length could be influenced by providing a stretch using the abdominal contents. Moreover, to see if this hypothesized change in length would influence the diaphragm’s function.
Method:
A quasi-experimental study was conducted from January to April 2012 with undergraduate
physiotherapy students as study participants. Seventy five study participants were assessed for baseline outcome measures at rest. They then underwent four body position changes after which each measurement was re-recorded. These body position changes were:
• lying in a head down tilt position at 15 degrees for 30 seconds
• lying in a head down tilt position at 15 degrees for two minutes
• lying in a head down tilt position at 30 degrees for 30 seconds
• lying in a head down tilt position at 30 degrees for two minutes
Ultrasound was used to measure the diaphragm length. Its function was recorded in terms of the expiratory flow generated and the thoracic expansion measured. Dyspnoea was recorded for a subjective view of tolerance of the position and vital signs were monitored throughout for the volunteers’ safety. ANOVA, Kruskal Wallis, Bartlett’s test and the student’s t test were used for statistical analysis.
Results:
All 75 participants completed the entire study and none were withdrawn as a result of
negative side effects. The results showed that the diaphragm could be stretched by using the abdominal contents in a head down tilt position (p=0.00). The mean and standard deviation for the greatest change from rest was 38.78mm (±11.51) on the left and 39.38mm (±11.92) on the right. There were no detrimental effects to the participants’ cardiovascular or pulmonary stability. Thoracic expansion and peak flow showed an insignificant change throughout the changes in position. Thoracic expansion had a mean change of 2.48cm (±0.86) with a p value of 0.54. Peak expiratory flow rate had a change of 428.94L/min (±95.01) with a p value of 0.98. These values were less than the normal expected values for the participants.
Conclusion:
A change in diaphragm length is possible by applying a stretch to the muscle. A stretch can be applied by placing the participant in a head down tilt position which allows the abdominal contents to push on the underside of the diaphragm in a cranial direction. No adverse effects occurred in healthy adult individuals during the different head-down tilt positions. Respiratory function did not show a significant improvement due to the change in diaphragm length as measured by peak expiratory flow rate and thoracic expansion.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/14598 |
| Date | 25 April 2014 |
| Creators | Schewitz, Jacqueline |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf, application/pdf |
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