Impingement of an artificial hip joint because of limited range of motion (RoM) during human activity is one of the main sources of hip joint failure. The aim of this article is to simulate the RoMs of hip joints during salat, the practice of formal worship in Islam.
Salat consists of several stages which can be represented with a cycle (raka’ah). Every raka’ah consists of standing, bowing (ruku’), straightening up (i’tidal), transition of standing toward prostrating, prostrating (sujud), and sitting. A virtual skeleton model was used to analyze the motion during salat for the possibility of the impingement occurrence.
The results of the simulation were presented in terms of maximum flexion, abduction, and internal or external rotation. The results also showed that the prostration position is similar in RoM with the Japanese zarei position and similar in RoM to pick up an object while sitting on a chair.
Specific aspects of salat such as the difference in position of the 2 legs at the last sitting position create an extreme RoM which in turn results in a high risk of impingement.