Journal of Rawalpindi Medical College (JRMC); 2016;20(2):124-128 124 Original Article Prevalence of Absence of Palmaris Longus Muscle in Kashmiri Population. Muhammad Junaid khan, Muhammad Saeed Shafi, Abaidullah Shoukat, Khawaja Abrar Ahmed, Saman Azad, Muhammad Zaheer-ud-Din Ayub,ZohaibIlyas, KinzaImtiaz, Amina Kanwal, RabiaTabbsum, Nimrah Masood, Saeeda Rashid, FahimaShoukat, Amber Latif . Department of Anatomy ,Azad Jamuuand Kashmir Medical College Muzaffarrabad. Background: To determine prevalence of absence of Palmaris Longis (PML) in Azad Jammu and Kashmir population. Methods: A descriptive, cross-sectional study carried out in seven districts of AJ&K. A pilot test questionnaire was used to collect demographic data by voluntary participants after an informed written consent. Master trainees were trained at AJK Medical College, Muzaffarabad, who were involved in data collection and clinical testing for the absence of PML and its effects on0 their daily activities. Results: Out of 700 subjects,132(18.9%) had agenesis of PML; 245 (35%) were left hand dominance and 455(65%) right hand dominance. among left handed 49 (33.9%) subjects had agenesis of PML. Among 455 total right hand dominance 83 (18.2%) subjects had agenesis of PML. Overall 28 subjects had unilateral and 104 bilateral agenesis of PML.This absence of PML did not affect their routine activities. Morphologically, different tendons of PML were also found. Conclusion:Prevalence of absence of PML in Kashmir was found in 18.9%. Its agenesis varies with body side, sex, and hand dominancy. Right hand and bilateral agenesis was greater than left hand dominance and unilateral respectively. Significance difference was observed between male and female agenesis(P< 0.05). Key Words: Palmaris Longus muscle, Laterality, Prevalence, Agenesis. Introduction Palmaris longus(PML) muscle has great variability in human beings. It shows variation with sex, laterality, race and hand dominancy. 1,2 It is a slender, fusiform muscle in the flexor compartment of forearm, which arises from the medial epicondyle of the humerus. It runs parallel and in between flexor carpi radialis and flexor carpi ulnaris muscles. Its tendon passes anterior to transverse carpal ligament, and is inserted into the palmer aponeurosis, with a tendinous slip to the short muscles of the thumb. It weakly flexes hand at the wrist, tenses the palmer aponeurosis 3,4 and aids in thumb abduction. 5 Although it contribute to the thumb movements, but doesn’t strengthen the gripping and pinching of hands. 6,7 Its absence was reported for the first time by Columbus in De Re Anatomica. 8 Previous work showed that PML agenesis is more common in male with right hand dominancy. Its prevalence with sex, age, race, side of body and hand dominancy has been studied by different noninvasive clinical studies. 9 PML has been studies extensively and prevalence of its agenesis varies significantly across the different population around the world from 0.6% Korean population, 1.02% in a Ugandan population, 2.9% in Asians, 3.4% in Japanese , 4.5% in African Americans, 4.6% in Chinese, 6.7% in Nigeria, 20.2% in Indians patients, 24% in North American Caucasians, 25% in Nigerian population, 26.6% in Turkish population and 38.6% in Bahraini population of Arabian region, and highest reported 63.9% in Turkish population. 7-16 Therefore it is important for surgeons, anatomist and physicians to be aware of the prevalence of the PML agenesis in the population or ethnic group being treated. Subjects and Methods A Descriptive, cross-sectional study was carried out in seven districts of Azad Jammu and Kashmir (AJ&K) by convenient sampling. Study was completed in 10 months from June 2012 to March 2013. A semi structured questionnaire was used to collect demographic data from all seven districts of AJ&K. It was pilot tested in student population of Azad Jammu and Kashmir medical college (AJKMC), Muzaffarabad. Only healthy people from all fields of life, with age ranging 5-85years were included 100,000 population of each district of AJ&K. The study was approved by the institutional review board (IRB) of AJKMC. All subject were included in this study after signing an informed consent. Questionnaire included name, age, and sex, blood group of subjects, hand dominancy, profession literacy level and laterality of agenesis of PML. In case of absence of PML, the subjects were interviewed for any difficulty experienced during/ professional activities. 26 voluntary participants of (2nd year)