Introduction: Neck of femur fracture is one of the most common fractures of elderly age group. Bipolar Hemiarthroplasty of Hip is most widely accepted treatment protocol. Posterior (Southern moore) approach is one of the widely used approach all over the world. In this approach Short external rotators are detached from their insertion and reattached. Hence there is a need to assess the function of External rotation of Hip post operatively. A Methods: Prospective study was carried out in patients with Neck of femur fracture who underwent Bipolar Hemiarthroplasty of Hip with Southern moore approach from May 2021 to May 2022 in a single institution. All patients were followed up and assessed at 6 weeks, 3 months and 6 months and function of short external rotators was assessed with Augustssons Strength test. Control for the muscle strength was considered opposite (Normal) side of hip. Patients with Any other ipsilateral fractures were excluded. Analysis of the data was done for the external rotator muscle strength at 6 weeks, 3 months and 6 months with comparison to normal hip of patient. The overall mean age was 69 years. Results: All the patient were followed up till 6 months post operatively. There was reduced strength of short external rotators in all the patients compared to normal hip at 6 weeks, with no significant difference in strength at 3 months. 12 out of 13 had equal muscle strength at 6 months. This study concludes that Detaching of Short external rotator in southe Conclusion: rn moore approach does not affect the muscle strength at 6 months. However it is found to be weaker in initial month.