Korkie E.1, van Heerden A.2
1University of Pretoria, School of Health Care Sciences, Physiotherapy, Pretoria, South Africa, 2University of Pretoria, School of Health Care Sciences, School of Health Care Sciences, Department of Physiotherapy, South Africa
Background: The Pectoralis minor (PM) muscle is an influential muscle in the dynamic movements of the scapula. Shortening of this muscle has been associated with shoulder pain, dysfunction, and impingement. Currently, there is no consensus on the normative value of Pectoralis Minor Muscle Index (PMI), thus it is difficult to diagnose muscle shortening as the source of dysfunction.Determining the normative value for PMI in the general population is necessary for establishing an outcome measure for health professionals to base their treatment and rehabilitation programs on.
Purpose: To determine the normative value of PMI in healthy individuals aged 18 - 24.
Methods: Thirty six (36) males and 38 females (n=74) between the ages of 18-24 were used in this study. A basic postural analysis was done following the prescribed plumb line. Each participants height was measured with a measuring tape in order to calculate the pectoralis minor index (PMI). The glenohumeral joint was evaluated with the shoulder quadrant test to eliminate intra articular shoulder pathology. The distance between the medial inferior angle of the coracoid process and lateral to the sterno-costal junction of the inferior aspect of the fourth rib was measured using the Vernier calliper® (INSIZE CO., LTD, 300mm). The average of three measurements were used to calculate the PMI.
Results: The PMI for healthy individuals (n=74) was found to be 10.5 on the left side and 10.3 on the right side.
Conclusion(s): The PMI values obtained in this study differs from the normative values used in other studies. A possible explanation is the bigger sample size. The value range previously used (7.65 - 8.61) is based on only six individuals, age and gender unknown.
Implications: The results from this study can serve as an outcome measure when upper limb function is evaluated or rehabilitated. Furthermore, this results can serve as a baseline for further studies within population groups with shoulder pathology and a different age group.
Funding acknowledgements: None
Topic: Musculoskeletal: upper limb
Ethics approval: Ethical approval was obtained from The Faculty of Health Sciences and Ethical Committee University of Pretoria (no. 562/2015).
All authors, affiliations and abstracts have been published as submitted.
