Retinacular structures, called pulleys, maintain the flexor tendons of the hand in constant relationship to the joint axes and promote economy and efficiency in finger flexion. This system is composed of the transverse carpal ligament, the palmar aponeurosis pulley, and the digital flexor pulley system. Of these three components, the digital pulleys are the most critical to finger flexion. In t...

OBJECTIVE This study aims to compare the morphology of the A1 pulley and flexor tendons in idiopathic trigger finger of digits other than the thumb between in neutral position and in the position with the interphalangeal joints full flexed and with the metacarpophalangeal (MP) joint 0° extended (hook grip position). METHOD A total of 48 affected digits and 48 contralateral normal digits from ...

Quantifying the pathological features of flexor tendon pulleys is essential for grading the trigger finger since it provides clinicians with objective evidence derived from microscopic images. Although manual grading is time consuming and dependent on the observer experience, there is a lack of image processing methods for automatically extracting pulley pathological features. In this paper, we...

This works shows the conceptual development of a finger mechanism for a prothestic hand. Three degrees of freedom of the finger are actuated by single DC motor, characterizing therefore an underactuated mechanical system. Mechanical torque developed by the motor is transmitted to the phalanges through tendons and is converted into flexion and extension torques by means of small pulleys. The ten...

In this paper we discuss the design of the 100G capturing robot from the point of view of dynamic pre-shaping where all finger links make contact with the target object simultaneously. After briefly explaining the overview of the 100G capturing robot, we mathematically formulate the dynamic pre-shaping problem where we discuss how to determine the mechanical parameters, such as pulley positions...

This report describes a rare case of extra-articular avulsion fracture of the flexor digitorum profundus tendon in a 59-year-old man is reported. A large avulsed fragment of bone was localized by radiography on the volar side of the middle phalanx. The avulsed bone fragment had torn the A4 pulley and had been caught by the C2 pulley. The fracture was extra-articular. The avulsed fragment was fi...