The measurement of finger and wrist range of motion (ROM) is of great importance to clinicians when assessing functional outcomes of therapeutic interventions and surgical procedures. The purpose of the study was to assess the repeatability of ROM measurements of the hand joints with manual goniometer and 3D motion capture system and to calculate the minimal detectable difference for both methods. Active finger and wrist joints ROM of 20 healthy volunteers were assessed using a manual goniometer and 3D motion capture system. Minimal detectable difference (MDD) and standard error of measurement (SEM) were calculated for both measurement systems and compared within the same task. Maximal ROM of all joints was registered twice on two different days to evaluate the test-retest repeatability. The intraclass correlation coefficients (ICC) was calculated and examined to determine if reliability ≥ 0.70 existed. MDD for the 3D motion capture was between 5 and 12° except for the metacarpophalangeal joint (MCP) 1, interphalangeal joint (IP), and MCP5. SEM values lay between 2 and 4° for all joints except for the MCP5, IP, and MCP1. For the goniometric measurements, MDD and SEM were between 12–30° and 4–11°, respectively. The reliability criterion (ICC > 0.7) was achieved for the ROM measurement with the 3D motion capture system for 94% of the joints and in only 65% of the joints with the manual goniometer. Joint ROM assessed with 3D motion analysis showed higher test-retest agreement demonstrating overall better repeatability for this method. Because of the smaller measurement error, the 3D motion capture system has a smaller MDD. Only individual test-rest differences bigger than the MDD can be considered as real changes, and therefore, in an experimental situation, the use of a more precise measurement method can greatly reduce the number of subjects needed for a statistical significance. Goniometer measurements of some joints should be carefully interpreted, due to a low repeatability and reliability. This study is approved by the Ethical Committee Zurich ( Kek-ZH-Nr: 2015-0395 ).

Climbing is a fast-growing sport, with one of the most common injuries being a rupture of the finger flexor tendon pulley. The strain on pulleys increases as finger joints flex. However, to our knowledge, no study has conducted a kinematic analysis of climbers’ fingers. Thus, this study aimed to examine finger kinematics during typical climbing tasks. Eleven elite climbers performed a sequence of four climbing moves, which were recorded by an optical motion capture system. Participants used crimp, half-crimp, and open-hand grips for three trials each, with the fourth condition involving campusing using any grip except crimp. Mean proximal interphalangeal joint (PIP) flexion during the holding phase was 87° (SD 12°), 70° (14°) and 39° (27°) for the crimp, half-crimp and open-hand grip, respectively. Hence, inter-individual PIP flexion ranges overlap between different gripping conditions. Two different movement patterns emerged in the open-hand grip, possibly influenced by the use of the little finger, leading to varying degrees of flexion in the middle and ring fingers. Avoiding little finger usage in the open-hand grip may reduce load during pulley rupture rehabilitation. The implications of PIP joint angle variability on individual pulley injury risk or prevention warrant further investigation. Motion capture proved effective for understanding finger kinematics during climbing and could guide future studies on pulley injury risk factors.

Climbing with extreme finger positions is a risk factor for osteoarthritic changes. Our initial study revealed a large variation in PIP joint flexion, especially in older climbers. This study compares finger joint motion between age groups and examines relations to degenerative changes. Nine young (~33.9 years) and 11 old (~55.8 years) participants climbed a defined boulder problem in four grip positions: crimp, half-crimp, open-hand and participant-selected grip. Finger and wrist kinematics were recorded by an optical motion capture system, contact forces were measured using four instrumented holds, osteophytes were assessed using ultrasound and maximal finger strength was measured separately. Older climbers demonstrated significantly (p < 0.0001) reduced PIP flexion compared to younger climbers in crimp (65° vs. 85°), half-crimp (53° vs. 75°), and self-selected grip positions (56° vs. 76°), with no difference observed in open-hand grip (33° vs. 37°; p = 0.44), which is biomechanically less demanding on the PIP joints. The self-selected grip corresponded to the half-crimp position. Osteophytes were rare in younger climbers (PIP: 8.33%, DIP: 16.67%) but common in older climbers (PIP: 68.18%, DIP: 81.82%), with a negative correlation with PIP flexion and a positive correlation with DIP flexion without age differences in maximal force (limited to male climbers). The half-crimp position generated higher maximal finger strength than the open-hand grip, and maximal finger strength was applied with a more open hand position. Older climbers apply lower finger forces and demonstrate less extreme finger joint kinematics associated with higher osteophyte prevalence, while preserving maximal finger strength, suggesting adaptive, joint-protective movement patterns.