Maximum Finger Force Prediction Using a Planar Simulation of the Middle Finger

Abstract

Maximum isometric finger-grip forces were predicted using a biomechanical model for plane motion of the middle finger. In the course of this study, mathematical representations of tendon displacement, the moment arm of tendon at the finger joints and muscle force-length relationship were investigated. The information gathered was applied to the model to estimate the maximum grip force of the middle finger gripping cylinders of different sizes. Muscle force per unit physiological cross-section area of 30 N/cm2 resulted in good agreement with measured force. However, for finger postures having an acute proximal interphalangeal joint angle, the estimated force was greater than that measured. Various joint angles were applied to the model to simulate the wrist and finger postures not limited to the cylinder grip. In general the finger force was greatest with the wrist in its extended position and at acute flexion of the proximal interphalangeal joint. The maximum finger force occurred at reduced metacarpophalangeal joint angles as the wrist joint changed from an extended position to a flexed one. It is also postulated that muscle force-length relationship is an important factor in muscle force predictions. The data obtained by this research are useful for the design of handles and the current model is applicable to the analysis of hand postures for workers using hand tools.

Towards a Realistic and Self-Contained Biomechanical Model of the Hand

“…An exponential relationship has been considered in this case (Lee & Rim, 1990;Kaufman et al, 1991), with b 1 and b 2 muscle dependent constants:…”

“…Muscle stress limit (S max ) has been obtained from Zajac (1989). Fibre and muscle lengths and the constants b 1 , b 2 for index finger muscles have been taken from Lee & Rim (1990); data for the remaining extrinsic muscles have been obtained from Lemay & Crago (1996) and for the remaining intrinsic muscles from Jacobson et al (1992). The muscle maximal lengthening velocity ( max ε ) has been taken to be 2.5 s -1 (Kaufman et al, 1991 Most of the muscles do not act directly on the bones, but transmit the force to the tendons, which finally insert into the bones.…”

“…The first biomechanical models of the hand were developed to explain and clarify the functionality of different anatomical elements. In this regard, we can find many works that studied the function of the intrinsic muscles (Leijnse & Kalker, 1995;Spoor, 1983;Spoor & Landsmeer, 1976;Storace & Wolf, 1979Thomas et al, 1968) and many others that tried to give an insight into the movement coordination of the interphalangeal joints (Buchner et al, 1988;Lee & Rim, 1990). Models for studying the causes and effects of different pathologies of the hand also appeared early on, such as the swan neck and boutonnière deformities or the rupture of the triangular ligament or the volar displacement of the extensor tendon (Smith et al, 1964;Storace & Wolf, 1979.…”

Grasp modelling with a biomechanical model of the hand

“…They were used to explain the function of different anatomical elements (Leijnse et al 1992; Leijnse and Kalker 1995;Spoor and Landsmeer 1976;Spoor 1983;Wolf 1979, 1982;Thomas et al 1968), the movement coordination of the interphalangeal joints (Buchner et al 1988;Lee and Rim 1990), to study the causes and effects of hand pathologies (Smith et al 1964;Wolf 1979, 1982) or even to obtain approximate values for the articular forces for testing prosthetic designs (Weightman and Amis 1982). By the year 2000, few attempts of developing a three-dimensional model were performed (Biryukova and Yourovskaya 1994;Casolo and Lorenzi 1994;Chao and An 1978;Chao et al 1976;Esteki and Giurintano et al 1995;Mansour 1997;Mansour et al 1994;Valero-Cuevas et al 1998).…”

Scalability of the Muscular Action in a Parametric 3D Model of the Index Finger

“…1,3,6,8,[10][11][12][13]15,16 For some purposes it is important to represent different population groups and percentiles, e.g., to aid therapists in the selection of the optimal handle diameter of personalised assistive devices for disabled people.…”