The Normal Active Range of Motion of the Index, Middle, Ring, and Little Fingers in a Sample of Indian Population
Authors: B.K Mohamed Ibrahim , Baba P. Umar Farooq , Singh Veena , Karanjkar Ankur , Madhavan Latha , Shah Raheeb Ahmad , Haq Ansarul , Pawar Manoj , Kumari Anupama , Panse Nikhil , G. Vishnubabu , Pandian Shyamnath Krishna , Sharma Anirudha , Krishnamoorthy Rajagopalan , Thatte Mukund , Bhat Anil , Krishnamoorthy Sridhar 
Published: August 2024

Abstract
Background The normative data for finger range of motion (ROM) are not available for the Indian population. The aim of our study was to measure the active ROM of finger joints in normal healthy volunteers in a sample of Indian population.
Materials and Methods This is a prospective observational study conducted as a part of the Indian normative data project of the Indian Society for Surgery of the Hand (ISSH). The study included one participating center from four geographical regions of the country. Certified goniometers were used to measure the ROM of fingers in all centers. A standardized methodology was devised. A pilot study was done to assess the interobserver and intraobserver reliability, following which data were collected by one measurement.
Results This pilot study was performed in 20 hands that showed good interobserver and intraobserver reliability correlation. A total of 390 hands were measured in four participating centers. Active flexion of metacarpophalangeal (MCP) joint was the highest in the middle finger (86.6 ± 10.4 degrees) followed by the index finger (86.0 ± 9.2 degrees), little finger (85.0 ± 8.4 degrees), and ring finger (84.2 ± 8.6 degrees). The index finger (97.2 ± 16.9 degrees) showed maximum proximal interphalangeal (PIP) joint flexion followed by the middle finger (96.2 ± 15.8 degrees), ring finger (96.0 ± 15.9 degrees), and little finger (91.8 ± 12.7 degrees). Distal interphalangeal (DIP) joint flexion increased from the index finger (81.6 ± 13.9 degrees) to the little finger (84.6 ± 12.9 degrees). The little finger MCP joint (26.3 ± 6.2 degrees) showed maximum extension followed by the index finger (25.7 ± 6.8 degrees), middle finger (24.7 ± 6.7 degrees) and ring finger (22.3 ± 7.1 degrees). The middle finger (15.6 ± 8.1 degrees) and ring finger (16.2 ± 8 degrees) had more PIP joint extension when compared to the index (13.7 ± 7.8 degrees) and little finger (13.2 ± 8.4 degrees). The ring finger (8.1 ± 6.8 degrees) and the middle finger (8.4 ± 6.9 degrees) had more DIP joint extension when compared with the index finger (6.0 ± 6.0 degrees) and the little finger (6.8 ± 6.7 degrees). Total active motion (TAM) of the middle finger (315.9 ± 31.0 degrees) was the maximum followed by the index finger (310.2 ± 27.3 degrees), ring finger (308.8 ± 29.1 degrees), and little finger (307.8 ± 25.2 degrees). Gender, body mass index (BMI), mother tongue, geographical location, and occupation were factors that had significant correlation, while no significant differences based on side, hand dominance, and age were noted.
Conclusion We have reported normative data of finger ROM and TAM for the index, middle, ring, and little fingers in the Indian population. Finger ROM in the Indian population is highly variable. The observed TAM in the Indian population is higher than what is reported earlier.