extensor and flexor injury mechanism hand

The wrist-driven flexor hinge orthosis (WDFHO) is a device used to restore hand function in persons with tetraplegic spinal cord injury by furnishing three-point prehension. We assessed the effectiveness and biomechanical properties of the WDFHO in 24 persons with cervical 6 or 7 tetraplegia who have severely impaired hand function. This study introduces a mechanical operating model to assess the efficiency of the WDFHO. Experimental results showed that pinch force increased significantly (p < 0.001) after using the WDFHO and was found to positively correlate with the strength of wrist extensor muscles (r = 0...

Tendon injuries of the hand are common and their treatment is surgically challenging. Precise knowledge of the anatomy of the extensor and flexor tendons in the hand is necessary to be able to perform a detailed clinical examination and to estimate adequately the extent of injury. Depending on the injury pattern, various conservative and surgical treatment options must be considered. Concerning the overall concept of the supply of tendon injuries of the hand, follow-up treatment is crucial to achieve an optimal functional outcome...

INTRODUCTION: Spontaneous rupture of the extensor pollicis longus (EPL) tendon has been reported after trauma, rheumatoid arthritis and sports. Rupture may also occur as a consequence of the use of anabolic steroids for recreational purposes, or systemic steroids for the treatment of a variety of medical conditions. CASE REPORT: We present a case report of a woman affected with a spontaneous EPL tendon rupture resulted 14 months after a corticosteroid injection for flexor tenosynovitis, "trigger finger," of the thumb...

Extensor tendon injuries are given less importance than the flexor tendon injuries; however, the extensor mechanism is more complicated than flexor tendon system, and regaining satisfactory function is a challenge. It has been reported that loss of digital flexion would affect grasp and power grip imposing greater functional loss than digital extensor lag. Zone 3 extensor tendon management is complex because of excessive scar formation limiting composite digital flexion and extension. The adhesions are more common if the tendon is immobilized for long period...

OBJECTIVE: To investigate the surgical method and effectiveness of repairing traumatic metacarpophalangeal joint defect by the composite tissue flap autograft of the second metatarsophalangeal joint. METHODS: Between June 2005 and December 2009, 6 cases (6 fingers) of traumatic metacarpophalangeal joint defect were treated with the composite tissue flap autograft of second metatarsophalangeal joint (containing extensor tendon, flexor tendon, proper digital nerve, planta or dorsal flap)...

OBJECTIVE: To evaluate the clinical efficacy of akin united flaps pedicled with dorsal carpal branch of ulnar artery in repairing complicated degloving injuries of the opposite fingers. METHODS: Between August 2005 and August 2009, 11 cases of complicated degloving injuries of single finger were treated, including 8 males and 3 females with an average age of 26 years (range, 19-55 years). The defect locations were thumb in 1 case, index finger in 7 cases, and middle finger in 3 cases, including 9 cases of mechanical injury and 2 cases of traffic accident injury...

PURPOSE OF THE STUDY: Intra-articular fractures of the distal radius are treated predominantly by open reduction and internal fixation with various types of angle-stable plates. In this study we compare functional and radiographic outcomes in patients with intra-articular distal radius fractures treated with either angle-stable plates with rigid-direction screw insertion or multidirectional angle-stable plates. MATERIAL AND METHODS: The LCP group included 37 patients with an average age of 50 years (range 20-81 years) who were treated using angle-stable plates with rigid-direction screw insertion (LCP, Synthes)...

The extensor mechanism of the fingers, hand, wrist, and forearm is extremely intricate. Disruptions to the extensor system are common and can be associated with poor patient outcomes when not treated appropriately. Although extensor tendon injuries receive much less attention in the literature than flexor tendon injuries do, several recent studies have examined this topic. This article presents an overview of the treatment of extensor tendon injuries, with a focus on recent developments.

This study utilized a portable data logger to measure the wrist angles and forearm flexor and extensor electromyography (EMG) of 21 hairstylists. The hairstylists were divided into two groups, one with 11 barbers (9 males and 2 females) specializing in men's hairdressing, and one with 10 hairdressers (2 males and 8 females) specializing in women's hairdressing. The standard haircut task was divided into three subtasks: hair cutting, washing and blow-drying. The mechanical exposures of the overall task and subtasks were quantified to compare how subtasks, occupational groups, and gender groups differ...

OBJECTIVE: To measure hand-specific functional performance after deep full-thickness dorsal hand burns. DESIGN: Descriptive, cross-sectional study. SETTING: The 2005 Phoenix Society's World Burn Congress, Baltimore, MD. PARTICIPANTS: Volunteer sample of burn survivors (N=32) with full-thickness dorsal hand burns with extensor mechanism involvement, who consented to participate. INTERVENTIONS: Not applicable...

PURPOSE: The vincula are specialized mesotendinous structures attaching to the flexor tendons of the hand. In addition to providing vascular supply to the tendons, the vincula can be mechanically important. The purpose of this study was to quantify the influence of intact vincula on digital flexion after flexor tendon laceration and to assess the ultimate strength and stiffness of the vincula. METHODS: The index, middle, and ring fingers of 12 fresh-frozen cadaveric fingers were dissected free at the level of the metacarpophalangeal joint, preserving at least 10 cm of the flexor and extensor tendons...

Upper extremity neuromuscular electrical stimulation (FNS) has long been utilized as a neuroprosthesis to restore hand-grasp function in individuals with neurological disorders and injuries. More recently, electrical stimulation is being used as a rehabilitative therapy to tap into central nervous system plasticity. Here, we present initial development of a rodent model for neuromuscular stimulation induced forelimb movement that can be used as a platform to investigate stimulation-induced plasticity. The motor points for flexors and extensors of the shoulder, elbow, and digits were identified and implanted with custom-built stimulation electrodes...

Knowledge of the functional anatomy of the extensor tendons with the sliding mechanism is essential for better understanding the surgical therapy and the postoperative care in the different trauma zones of the extensor tendon. In addition the localization of the injury is very important for the clinical findings, therapy, after-care and long term prognosis. Anatomical facts, injury mechanisms and associated injuries have to be considered in the therapy concept. Several therapy possibilities are known: immobilizing with splint for the closed rupture in zone I, reinsertion in zone III (with a temporary Kirschner-wire-pinning), tendon suture, tendon transplantation or transposition...

The amplitude and mean power spectral frequency (MNF) of the electromyogram (EMG) of flexor digitorum superficialis and extensor carpi radialis muscles were monitored during cyclic, force-varying, constant-posture, submaximal, grip-force contractions until endurance. These contractions are reminiscent of work tasks associated with the risk of repetitive stress injuries. Based on recommendations from a prior cross-comparison study of these data, the cyclic grip-force contractions were temporally aligned cycle-by-cycle to the achieved grip force profile, then EMG amplitude was computed using signal whitening (500 ms window) and MNF was computed using the short-time Fourier transform (500 ms window)...

In the course of rheumatoid arthritis, changes to tendons occur in different areas. This can lead to rupture if not prevented at an early stage. In particular, regions with extreme joint thickness, high mechanical wear and tear and narrow regions present a higher risk of synovitis. This primarily affects the tendons of the hand, where the extensor digitorum minimus tendon and the extensor and flexor pollicis tendons are most at risk. There is a high possibility of rotator cuff lesion in the shoulder area during the course of a secondary synovitis dependent raised shoulder, or by bursitis or tendonitis...

PURPOSE: This pilot study examined the effects of neuromuscular electrical stimulation (NMES) therapy on upper limb impairment in children with cerebral palsy, specifically addressing spasticity, heightened passive resistance to wrist rotation, coactivation, and weakness. METHODS: Eight subjects, aged five to 15 years, with spastic hemiparesis subsequent to brain injury, participated in three months of NMES therapy, targeting the wrist flexor and extensor muscles...

STUDY DESIGN: Repeat measures design. OBJECTIVE: The purpose of this study was firstly, to describe a simple clinical tool that can be used to measure the extensibility of the flexor pollicis longus (FPL) muscle; secondly, to test its reliability; and thirdly, to attain some 'normative' data of the extensibility of the FPL muscle in a representative sample of people with tetraplegia. SETTING: A spinal cord injury unit in Sydney. SUBJECTS: A total of 37 people (62 hands) with C4-C7 tetraplegia...

BACKGROUND: An experiment has recently been conducted to evaluate and compare the differences in tendon excursions between the flexor digitorum profundus and superficialis using three mobilization techniques. No previous studies deal with the total joint excursions with constant tendon length. The purpose of this study was to investigate the coordinated motion between the finger and wrist joints resulting from passive tension of the muscles while performing synergistic wrist motion. METHODS: The relative joint positions of the hand and wrist were measured using a three-dimensional motion analysis system with external retroreflective markers 2 mm in diameter placed on the dorsal surface of the hand...

PURPOSE: Improper lifting techniques may increase injury risks and decrease performance. The aim of this study was to compare and contrast biomechanical parameters between sumo and conventional style deadlifts and between high- and low-skilled lifters who participated in the powerlifting event during the 1999 Special Olympics World Games. METHODS: Two synchronized video cameras collected 60 Hz of data from 40 subjects. Parameters were quantified at barbell liftoff (LO), when the barbell passed the knees (KP), and at lift completion...

The family physician often provides the first and only medical intervention for fingertip injuries. Proper diagnosis and management of fingertip injuries are vital to maintaining proper function of the hand and preventing permanent disability. A subungual hematoma is a painful condition that involves bleeding beneath the nail, usually after trauma. Treatment requires subungual decompression, which is achieved by creating small holes in the nail. A nail bed laceration is treated by removing the nail and suturing the injured nail bed...