An Indigenous Study on The Palmaris Longus Muscle Anatomical Variations

Introduction: The Palmaris longus muscle is one of the superficial flexor muscles of the forearm that flexes the hand on the wrist and makes the palmar aponeurosis tense for gripping. It is variable both in number and form like inverted, doubled, split, three-headed or absent palmaris longus. These variabilities may cause clinical features due to abnormal pressure on the median and ulnar nerves. Its tendon can be used as a graft in various transplant surgeries. Aims & Objectives: This study was conducted to observethe number of cadavers showing anatomical variations of palmaris longus muscle in the Pakistani population. Place and Duration of Study: This study was conducted in the Anatomy Department of FMHCM&D, Lahore. The duration of the study was January 2019 - January 2022. Material & Methods: Cadaveric dissected upper limb specimens with normal palmaris longus were listed in Group: A, upper limbs having reversed palmaris longus were listed in Group: B, while upper limbs with absent palmaris longus were listed in Group: C. The RPL (reversed palmaris longus) muscle is the structure that is tendinous proximally and muscular distally (opposite of normal palmaris longus).Results were tabulated and percentages calculated. Results: It was observed that out of 80 dissected cadaveric upper limbs,77 (96.25%) showed normal palmaris longus while a right cadaveric upper limb (1.25%) showed anomalous palmaris longus with the reversed tendon. Palmaris longus muscle was found absent in two cadaveric left upper limbs (2.5%). Conclusion: Our study highlighted the percentage of different anatomical variations of the Palmaris longus muscle in terms of its presence with reversed tendons as well as its absence in a few human cadaveric upper limbs. This information may help anatomists, radiologists, physiotherapists and plastic surgeons.