Measurement of external three-dimensional interphalangeal loads applied during activities of daily living.

OBJECTIVE To measure the external three-dimensional loads applied to the interphalangeal joints during activities of daily living. DESIGN A six-degree-of-freedom force transducer was used in conjunction with motion analysis studies. BACKGROUND There is a lack of accurate three-dimensional load data available for input into biomechanical models of the hand. METHODS A new force transducer has been incorporated into several housings representing objects in domestic use: a jar, a tap, a key in a lock and a jug kettle. Three-dimensional kinematic data were acquired using a six-camera VICON motion analysis system. Twelve healthy volunteers took part in the study, which compared power and precision grips in 'opening' and 'closing' activities. RESULTS Large external forces and moments are applied to the middle and distal phalanges in sagittal, coronal and axial directions. Average inter-segmental forces of up to 25 N and average moments of up to 1.8 Nm are experienced at the proximal interphalangeal joint. CONCLUSIONS The results show that complex loading patterns are associated with routine activities of daily living. RELEVANCE Biomechanical models of the interphalangeal joints are limited in their ability to accurately predict tendon and joint forces by the quality of the input data obtained by conventional measurement techniques. Models have tended to rely on hypothetical values of external forces acting on the hand and are over-simplified or limited to two-dimensions. The results from the current study challenge the validity of these simplified models and offer a more complete picture of the complex loading system applied to the finger during daily life.

[1]  K. Rim,et al.  Measurement of finger joint angles and maximum finger forces during cylinder grip activity. , 1991, Journal of biomedical engineering.

[2]  V Wright,et al.  An evaluation of the dynamic qualities of isometric grip strength. , 1988, Annals of the rheumatic diseases.

[3]  E Y Chao,et al.  Three-dimensional force analysis of finger joints in selected isometric hand functions. , 1976, Journal of biomechanics.

[4]  A A Amis,et al.  Finger joint force predictions related to design of joint replacements. , 1982, Journal of biomedical engineering.

[5]  Swanson Ab,et al.  The strength of the hand. , 1970 .

[6]  Edmund Y. S. Chao,et al.  Biomechanics of the hand : a basic research study , 1989 .

[7]  W. K. Purves,et al.  Resultant finger joint loads in selected activities. , 1980, Journal of biomedical engineering.

[8]  F. Veldpaus,et al.  Finite centroid and helical axis estimation from noisy landmark measurements in the study of human joint kinematics. , 1985, Journal of biomechanics.

[9]  C D Mote,et al.  A method of measuring fingertip loading during keyboard use. , 1994, Journal of biomechanics.

[10]  Edmund Y. S. Chao,et al.  HAND FUNCTIONAL STRENGTH ASSESSMENT AND ITS CLINICAL APPLICATION , 1989 .

[11]  A A Amis,et al.  Variation of finger forces in maximal isometric grasp tests on a range of cylinder diameters. , 1987, Journal of biomedical engineering.

[12]  R. L. Linscheid,et al.  Forces in the normal and abnormal hand , 1985, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[13]  J. Webster,et al.  External finger forces in submaximal five-finger static pinch prehension. , 1992, Ergonomics.

[14]  A C Nicol,et al.  A force transducer to measure individual finger loads during activities of daily living. , 1999, Journal of biomechanics.