Carpal Muscles Research Articles

Predicting thenar motor branch anatomy for a safer carpal tunnel release

PurposeAnatomic variations of the thenar motor branch of the median nerve (TMB) that place the nerve more ulnarly in the palm can increase the risk for iatrogenic injury to the nerve during carpal tunnel release. This study examines the prevalence of an origin of the TMB that is more ulnar than its typical branching from the radial aspect of the median nerve and explores whether the appearance of the palmar intrinsic muscles at surgery can predict an unusual TMB origin prior to visualizing the TMB itself. MethodsA prospective study of patients undergoing carpal tunnel release surgery was undertaken to document the take-off point of the TMB along the circumference of the median nerve and the presence or absence of intrinsic muscle obscuring the distal transverse carpal ligament. ResultsForty-one hands were evaluated. Eleven (26.8 %) demonstrated transverse carpal muscle. The most common origin of the TMB was from the radial aspect of the median nerve (56.1 %). In approximately 20 % of nerves, the TMB originated near its anterior midline. There was a statistically significant relationship between the TMB originating more ulnarly and the presence of transverse carpal muscle. ConclusionsThis study introduces a new classification system for further defining anatomic variations of the TMB. When transverse carpal muscle is absent, the TMB is highly likely to arise from the radial aspect of the median nerve. In the presence of transverse carpal muscle, the origin of the TMB is unpredictable and is significantly more likely to arise from the median nerve more ulnarly than is typically seen. Under these circumstances, attempts should be made to identify the TMB prior to completing ligament division.

An anatomical variation to consider for a safe carpal tunnel surgery: transverse carpal muscle

An anatomical variation to consider for a safe carpal tunnel surgery: transverse carpal muscle

An anatomical variation to consider for a safe carpal tunnel surgery: transverse carpal muscle

An anatomical variation to consider for a safe carpal tunnel surgery: transverse carpal muscle

Accessory Hand Muscles Over the Transverse Carpal Ligament: An Obstacle in Carpal Tunnel Surgery

Carpal tunnel syndrome (CTS) is an entrapment neuropathy caused by compression of the median nerve throughout the carpal tunnel. It is the most common entrapment neuropathy, with an estimated prevalence of 4%-7%. Surgical management is more effective in moderate to severe and severe CTS. CTS recurs in approximately 20% of patients, and up to 12% of these patients require reoperation. Knowledge of normal anatomy and variations would improve the success rate of the index surgery. Atypical causes of CTS were reported, including ganglion cysts, synovial hypertrophy, lipomas, bone fracture, bone fragments, tumor of soft tissues or bones, neurofibromas, neuromas, vascular malformations, and accessory muscles. Accessory muscles are commonly detected in upper limbs. However, their concomitant presentation with CTS has rarely been reported. We aimed to present different accessory muscles diagnosed during CTS surgery through a systematic review of the literature with our exemplary case. A systematic review/meta-analysis was performed concomitant with a case presentation. Accessory muscles associated with CTS were as follows: palmaris longus, 28.6%; lumbrical muscles, 19.3%; palmaris profundus, 17.8%; flexor digitorum superficialis, 16.1%; transverse carpal muscle, 5%; flexor digitorum indicis, 4.2%; flexor superficialis indicis, 4.2%; flexor sublimis, 0.8%; accessory superficialis longus, 0.8%; flexor pollicis longus, 0.8%; abductor digiti minimi, 0.8%; abductor digiti quinti, 0.8%; and flexor digitorum superficialis brevis, 0.8%. Accessory muscles were mostly noticed during CTS surgery (88.2%). Knowledge of possible variations within the carpal tunnel would improve the surgeon's capability during CTS surgery.

Forearm and Hand Muscles Exhibit High Coactivation and Overlapping of Cortical Motor Representations

Most of the motor mapping procedures using navigated transcranial magnetic stimulation (nTMS) follow the conventional somatotopic organization of the primary motor cortex (M1) by assessing the representation of a particular target muscle, disregarding the possible coactivation of synergistic muscles. In turn, multiple reports describe a functional organization of the M1 with an overlapping among motor representations acting together to execute movements. In this context, the overlap degree among cortical representations of synergistic hand and forearm muscles remains an open question. This study aimed to evaluate the muscle coactivation and representation overlapping common to the grasping movement and its dependence on the stimulation parameters. The nTMS motor maps were obtained from one carpal muscle and two intrinsic hand muscles during rest. We quantified the overlapping motor maps in size (area and volume overlap degree) and topography (similarity and centroid Euclidean distance) parameters. We demonstrated that these muscle representations are highly overlapped and similar in shape. The overlap degrees involving the forearm muscle were significantly higher than only among the intrinsic hand muscles. Moreover, the stimulation intensity had a stronger effect on the size compared to the topography parameters. Our study contributes to a more detailed cortical motor representation towards a synergistic, functional arrangement of M1. Understanding the muscle group coactivation may provide more accurate motor maps when delineating the eloquent brain tissue during pre-surgical planning.

Rationale for the use of osteopathic correction methods in patients with Sudeck syndrome

Introduction. One of the serious complications after limb injuries is the development of Sudeck-Turner syndrome (refl ex sympathetic dystrophy). Various methods of conservative treatment are used: drug therapy, physiotherapy, exercise therapy, blockade, and finally with prolonged and unsuccessful conservative therapy, various types of surgical techniques. However the severity and duration of the disease, the treatment low efficiency, the unpredictability of the pathological process outcome forces traumatologists looking for new treatment methods. Osteopathic correction could be one of these methods.The goal of research — to substantiate the use of osteopathic correction methods in patients with Sudeck syndrome.Materials and methods. 11 patients suffering from post-traumatic pain syndrome were examined and treated for complications of distal forearm fractures. 5 patients were included in the control group and received treatment according to standard methods. 6 patientswere included in the main group and received osteopathic correction. Dynamics of patients′ condition changes was evaluated by the photographic method, X-ray of the wrist joint in 2 projections, assessment of carpal muscle strength on 6-point scale, the assessment of wrist strength by dynamometrical carpal dynamometer. The osteopathic status of patients was also assessed at the beginning and at the end of treatment. Statistical analysis was performed using nonparametric statistics.Results. It was found that osteopathic correction of the patients suffering withSudeck syndrome reduces the treatment time for this patients′category. The study showed that the treatment period is reduced by an average of 35 days. In addition, in patients receiving osteopathic correction, the function of the damaged limb is restored to a fuller extent: only in 33% of cases there was a limitation of motion range (compared with 100 % in the control group), there was no edema (compared with 60 % in the control group), the carpal force increased by 66 % (48 % — the control group), in 50 % of the patients the carpal force was fully restored.Conclusion. The conducted research allowed comparing the possibilities of traumatological rehabilitation treatment of thepatients suffering withSudeck syndrome, and the treatment using osteopathic methods of examination and correction. The obtained results allow to recommend osteopathic correction in the complex of measures for the treatment of Sudeck syndrome.

Muscular control of scapholunate instability. An experimental study

PurposeAs long as the neuromuscular stabilizers are intact, a lesion of the scapholunate ligament may or may not progress to a carpal instability. The mechanisms by which the muscles compensate this defect are not very well known. We designed an experimental study with the aim of clarifying these mechanisms. Material and methodUsing 10 fresh wrists, with no pre-existing lesions, we studied the movements of the scaphoid, triquetrum and capitate produced by the isometrical loading of the muscles which move the wrist, each of them isolated or combined, before and after cutting off the scapholunate ligaments. To do this, we placed sensors in each of these bones and used the Fastrack® system to record these movements. ResultsThe simultaneous loading of the muscles of the wrist produce rotational movements in flexion and supination of the proximal carpal row. After cutting off the scapholunate ligaments, the scaphoid rotates in pronation and flexion, while the triquetrum rotates in pronation and extension. In this situation of a scapholunate lesion, the muscles that worsen the carpal dexasation are the extensor carpi ulnaris and flexor carpi ulnaris. On the other hand, the isolated loading of the radial muscles reduces the scapholunate diastasis, thus improving the carpal alignment. ConclusionIn dynamic scapholunate instabilities, isometric contraction of the ulnar carpal muscles must be avoided, as it promotes the scapholunate diastasis. The rest of the muscles have the opposite effect, stabilizing the carpus when primary stabilizers have failed.

Control muscular de la inestabilidad escafolunar. Estudio experimental

PurposeAs long as the neuromuscular stabilizers are intact, a lesion of the scapholunate ligament may or may not progress to a carpal instability. The mechanisms by which the muscles compensate this defect are not very well known. We designed an experimental study with the aim of clarifying these mechanisms. Material and methodUsing 10 fresh wrists, with no pre-existing lesions, we studied the movements of the scaphoid, triquetrum and capitate produced by the isometrical loading of the muscles which move the wrist, each of them isolated or combined, before and after cutting off the scapholunate ligaments. To do this, we placed sensors in each of these bones and used the Fastrack system to record these movements. ResultsThe simultaneous loading of the muscles of the wrist produce rotational movements in flexion and supination of the proximal carpal row. After cutting off the scapholunate ligaments, the scaphoid rotates in pronation and flexion, while the triquetrum rotates in pronation and extension. In this situation of a scapholunate lesion, the muscles that worsen the carpal dexasation are the extensor carpi ulnaris and flexor carpi ulnaris. On the other hand, the isolated loading of the radial muscles reduce the scapholunate diastasis, thus improving the carpal alignment. ConclusionIn dynamic scapholunate instabilities, isometric contraction of the ulnar carpal muscles must be avoided, as it promotes the scapholunate diastasis. The rest of the muscles have the opposite effect, stabilizing the carpus when primary stabilizers have failed.

인체 수관절 근육의 진동 응답

This paper examines the dynamic characteristics of a human carpal muscle through theoretical analysis and experiment. The carpal muscle was modeled as a 1-DOF vibration system and vibration response due to a ramp function force was calculated. The electromyogram signal corresponding to the muscle excitation force was measured, and the excitation force function of an envelope curve from the electromyogram signal was extracted. The ramp input function of electrical stimulation to the carpal muscle was applied by using a device for functional electrical stimulation, and the angular displacements corresponding to steady state response were measured. Theoretical calculations of the vibration response displacements were compared with the experimental results of the angular displacements, and have shown a good agreement with the result that is linearly proportional to the excitation force magnitude. As a result, the relationship between the input current of the electrical stimulation and the excitation force magnitude was inferred. The result was shown that it can be applied to develop rehabilitation training devices.

인체 수관절 운동과 근전도의 상관관계

본 논문은 인체 수관절 운동과 표면 근전도의 상관관계를 실험적으로 다룬다. 수관절의 해부학적 구조를 분석하여, 수관절 운동 형상을 파악하고 운동을 발생시키는 주요 근육을 선정하였다. 수관절 재활 훈련 장치를 이용하여 수관절 운동에 저항하는 토크를 가하고, 이 때 주요 근육에서 토크에 따른 표면 근전도 신호를 측정하였다. 측정된 표면 근전도 신호의 크기를 계산하여 수관절 운동과의 연관성 분석에 사용하였다. 실험 결과로부터 수관절 토크와 표면 근전도 신호의 크기가 토크 0.1 N m 이하의 수관절 운동에서는 선형적으로 비례함을 밝혔고, 수관절 근육의 단면적에 따라 표면 근전도 신호의 크기도 선형적으로 비례함을 확인하였다. 또한 수관절 운동에 관여하는 각 근육의 기여도를 분석한 결과, 각 운동을 발생시키는 가장 주도적인 2개의 근육 중에서 한 근육의 기여도가 약 60 %로서 일관성 있게 나타났다. 이러한 세 가지 실험 결과로 좀 더 정교한 수관절 재활 훈련 장치나 로봇 등을 제작하는데 응용할 수 있다.

Transverse carpal muscle in association with carpal tunnel syndrome: Report of three cases

Anomalous muscles of the upper extremity are common, however, symptomatic anomalies causing CTS are rare. Three cases of CTS that are believed to be caused by an anomalous muscle located palmar to the transverse carpal ligament with transversely oriented muscle bundles is presented. Despite the arguments in literature, this is certainly an anomalous muscle that can be encountered during carpal tunnel release and be problematic to manipulate when minimally invasive approaches are chosen.