Background and Aim: Scapular muscles stabilization and neuromuscular control are important factors in shoulder function during dynamic activities. The three-dimensional pattern of integrated movement between gleno-humeral and scapula-thoracic joints is known as the scapula-humeral rhythm. More involved rotator cuff and scapular muscles causes more motor units are being recruited, therefore perhaps with loading on scapular muscles, can evaluate muscles role in scapular position more accurately and comprehensively.

Materials and Methods: Thirty male basketball players, aged between 20 to 40 years were recruited for modified lateral scapular slide test. The linear distance between inferior angle of scapula and spinous process of T7-8 was examined in 90 degrees of scaption without load and with 1 kg loading by two examiners in one session using the caliper. One of the examiners repeated the test in next week.

Results: Amount of inter and intra-rater intra-class correlation coefficient (ICC) for 90 degrees of unloaded scaption was 0.73 and 0.82, respectively and for 1 kg loading position was 0.54 and 0.86, respectively. Amount of standard error of measurement (SEM) in inter and intra-rater measurements for 90 degrees of unloaded scaption was 0.83 and 0.59 cm, respectively and for 1 kg loading position was 0.97 and 0.45 cm, respectively.

Conclusion: 1 kg loading in scaption, did not significantly improve the reliability of the test that shows the amount of load is not appropriate to activate the muscles in the athletes.

Keywords: Loading in scaption, Lateral scapular slide test, Athletes, Reliability .