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Key human anatomy and physiology principles as they relate to rehabilitation engineering
Published in Alex Mihailidis, Roger Smith, Rehabilitation Engineering, 2023
Qussai Obiedat, Bhagwant S. Sindhu, Ying-Chih Wang
Another factor to consider is how many joints a muscle crosses in the body. Single-joint muscles are those that span only one joint, while multi-joint muscles span two or more joints. The importance of this factor is that the force magnitude and joint range of motion (ROM) will vary depending on the relative position of each joint in the multi-joint muscles. For example, try to make a fist and flex your wrist, note the ROM of your wrist. Now flex your wrist while your hand is open. You will notice that the ROM increased. The reason for this increase is due to the length of the extensor digitorum muscle. The extensor digitorum spans over the wrist and the finger joints and is responsible for the extensions of the fingers and assists in the wrist extension as well. When you are making a fist with your hand, the tendons of the extensor digitorum are stretched, thus minimizing the available ROM for wrist flexion. Major joints in the upper and lower limbs, movements in each joint, and the muscles responsible for each movement are summarized in Table 3.4.
Biomechanical evaluation of the stability of extra-articular distal radius fractures fixed with volar locking plates according to the length of the distal locking screw
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Gyung-Hwan Oh, Hak-Sung Kim, Jung Il Lee
Distal radius fractures (DRFs) are a common injury encountered by orthopedic surgeons. Recently, an operative treatment using a volar locking plate (VLP) has emerged as a popular treatment for unstable DRFs. (Chung et al. 2009; Obert et al. 2013) However, the increased use of VLP has led to various postsurgical complications. Extensor tendon complications such as extensor tenosynovitis, extensor pollicis longus rupture, and extensor digitorum rupture after VLP fixation have been extensively reported. (Benson et al. 2006; Soong et al. 2011; Bentohami et al. 2014; Caruso et al. 2015; Azzi et al. 2017; Thorninger et al. 2017) These complications related to extensor tendons can occur due to inappropriate surgical technique (injury by depth gauge or drill bit) or dorsal protrusion of the distal screw.