Carpal Tunnel Biomechanics – Displacement and Associated Intra-Carpal Tunnel Pressure Studies during Finger Flexion

2015 ◽  
pp. 80-83
Author(s):  
K. Liong ◽  
S. J. Lee ◽  
A. Lahiri ◽  
H. P. Lee
Keyword(s):  
Carpal Tunnel ◽  
Finger Flexion

Biomechanical Changls of Finger Flexion After Carpal Tunnel Release with Respect to Wrist Positions

1996 ◽  
Vol 31 (6) ◽  
pp. 1247
Author(s):  
Ho Jung Kang ◽  
Eung Shick Kang ◽  
Sang Gil Lee ◽  
Daniel P. Mass
Keyword(s):  
Carpal Tunnel ◽  
Carpal Tunnel Release ◽  
Finger Flexion

scholarly journals Finger Flexion Deformity and Carpal Tunnel Syndrome Caused by Gouty Tophus

2015 ◽  
Vol 42 (8) ◽  
pp. 1530-1531 ◽  
Author(s):  
VARINDER KUMAR ◽  
CRAIG RODNER ◽  
SANTHANAM LAKSHMINARAYANAN
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Carpal Tunnel ◽  
Flexion Deformity ◽  
Finger Flexion ◽  
Tunnel Syndrome ◽  
Gouty Tophus

Lumbrical Muscle Incursion into the Carpal Tunnel During Finger Flexion

1994 ◽  
Vol 19 (4) ◽  
pp. 434-438 ◽  
Author(s):  
T. K. COBB ◽  
K.-N. AN ◽  
W. P. COONEY ◽  
R. A. BERGER
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Carpal Tunnel ◽  
Work Place ◽  
Full Extension ◽  
Work Related ◽  
Finger Flexion ◽  
Tunnel Syndrome ◽  
Lumbrical Muscle ◽  
Trauma Disorders ◽  
Possible Cause

Carpal tunnel syndrome is one of the many so-called cumulative trauma disorders thought by some to be related to the performance of repetitive tasks in the work-place. The cause of this disorder is unknown. We have observed lumbrical muscle incursion into the carpal tunnel during finger flexion. This study was conducted to determine the amount of this incursion in normal wrists. Five cadaver upper limbs were analyzed radiographically with radiopaque markers on the flexor retinaculum and the lumbrical muscle origins in four finger positions: full extension, 50% flexion, 75% flexion, and 100% finger flexion. The lumbrical muscle origins were an average of 7.8 mm distal to the carpal tunnel in full finger extension. They moved an average of 14 mm into the carpal tunnel with 50% finger flexion, 25.5 mm with 75% flexion, and 30 mm with 100% flexion. Abnormal lumbrical muscles have been cited as a possible cause of carpal tunnel syndrome. These findings suggest that lumbrical muscle incursion during finger flexion is a normal occurrence and is a possible cause of work-related carpal tunnel syndrome.

An Anechoic Space at the Carpal Tunnel Inlet is a Consistent Ultrasonographic Entity which Accommodates Tendon Displacement during Finger Flexion

2016 ◽  
Vol 21 (02) ◽  
pp. 222-228
Author(s):  
Bing Howe Lee ◽  
Chin Hock Goh ◽  
Amitabha Lahiri
Keyword(s):  
Median Nerve ◽  
Carpal Tunnel ◽  
Prevalence Rate ◽  
Normal Subjects ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Finger Flexion ◽  
Normal Individuals ◽  
Asymptomatic Volunteers

Background: We consistently observed the presence of anechoic spaces on standard ultrasonographic imaging of the carpal tunnel inlet in normal subjects. These spaces change in size during finger flexion and have not been characterized in a large sample of normal individuals. Ultrasonographic quantification of these spaces may indicate the available space in the region of the carpal tunnel, which allows the normal motion of tendons and the median nerve. Methods: Transverse ultrasonographic images of the carpal tunnel inlet from 33 asymptomatic volunteers were obtained at Position A (fingers in extension) and B (fingers in flexion). Cross-sectional area (CSA), perimeter and position of anechoic space relative to median nerve were recorded. Results: Analysis showed a 75.4% prevalence rate of a single anechoic space. Two discrete patterns were observed. 89.1% had a decrease in CSA and perimeter of anechoic space from Position A to B while 10.9% exhibited an increase. Mean position of the anechoic space is ulnar (7.49 ± 3.57 mm) and dorsal (2.18 ± 1.28 mm) to the median nerve. Conclusions: A consistent anechoic space at the carpal tunnel inlet is seen in 75.4% of normal hands and can be quantified (cross sectional area 11.75 ± 7.36 mm2). It allows for the accommodation of flexor tendons during finger flexion.

MID-MOTION DEFORMATION OF MEDIAN NERVE DURING FINGER FLEXION: A NEW INSIGHT INTO THE DYNAMIC AETIOLOGY OF CARPAL TUNNEL SYNDROME

Hand Surgery ◽  
2013 ◽  
Vol 18 (02) ◽  
pp. 193-202 ◽  
Author(s):  
Kyrin Liong ◽  
Amitabha Lahiri ◽  
Shujin Lee ◽  
Dawn Chia ◽  
Arijit Biswas ◽  
...  
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Carpal Tunnel ◽  
Symptom Relief ◽  
Mechanical Compression ◽  
Dynamic Component ◽  
Finger Flexion ◽  
Dynamic Ultrasound ◽  
Tunnel Syndrome ◽  
Gliding Movement ◽  
Insight Into

Carpal tunnel syndrome (CTS) exists in a spectrum of severity and symptoms with a dynamic component. We aim to study dynamic nerve-tendon interrelationships in normal and mild CTS wrists during a fist motion, with dynamic ultrasound. We observed that in normal wrists, the nerve arcs in an ulnar-volar direction and changes from a circular shape to a flat oval during motion. In CTS candidates, however, the curvature and distance of the nerve's path are reduced, while nerve shape remains relatively constant. In all candidates, the nerve is compressed against the flexor retinaculum, with the nerve subject to less compression in normal candidates as it moves dorsally into a recess. These findings suggest that besides mechanical compression from increased carpal tunnel contents alone, a decrease in nerve gliding movement may lead to CTS symptomatology. Furthermore, we identified that maximum nerve deformation occurs mid-motion, supporting the use of wrist splints for symptom relief.

A Study of the Dynamic Relationship of the Lumbrical Muscles and the Carpal Tunnel

1994 ◽  
Vol 19 (4) ◽  
pp. 439-443 ◽  
Author(s):  
N. W. YII ◽  
D. ELLIOT
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Carpal Tunnel ◽  
Provocation Test ◽  
Dynamic Relationship ◽  
Finger Flexion ◽  
Tunnel Syndrome ◽  
Lumbrical Muscles ◽  
Relationship Of

The dynamic relationship of the lumbrical muscles to the carpal tunnel was studied in 35 hands in 32 patients and their movement into the tunnel on finger flexion was examined with a view to its use as a diagnostic provocation test in carpal tunnel syndrome.

BIPHASIC MOTION OF THE MEDIAN NERVE IN THE NORMAL ASIAN POPULATION

Hand Surgery ◽  
2015 ◽  
Vol 20 (01) ◽  
pp. 73-80 ◽  
Author(s):  
C. H. Goh ◽  
B. H. Lee ◽  
Amitabha Lahiri
Keyword(s):  
Phase I ◽  
Median Nerve ◽  
Carpal Tunnel ◽  
Normal Population ◽  
Asian Population ◽  
Deformation Pattern ◽  
Full Extension ◽  
Finger Flexion ◽  
Tunnel Syndrome ◽  
Full Flexion

Background: The biomechanical interaction between the median nerve and the flexor tendons is an important consideration in Carpal tunnel syndrome (CTS). We aim to quantify the displacement and compressive deformation pattern of the median nerve in various stages of finger flexion in the normal population at the inlet of the carpal tunnel. Methods: Transverse ultrasounds images were taken at the carpal tunnel inlet during full-extension, mid-flexion and full flexion. The displacement, distance, Feret's diameter, and perimeter of the median nerve were calculated and compared between each position. Results: Biphasic median nerve motion was observed, with a displacement of 2.84 ± 3.49 mm in the ulnar direction from full-extension to mid-flexion (Phase I) and a further 0.93 ± 3.04 mm from mid-flexion to full flexion (Phase II). Of 49 hands, 37 (75.5%) exhibited ulnar displacement in Phase I while 12 (24.5%) exhibited radial displacement. Feret's diameter (5.95 ± 1.08 mm) and perimeter (13.28 ± 2.09) of the median nerve were greatest in the mid-flexed position. Conclusion: In a healthy Asian population, the median nerve has a biphasic motion during finger flexion, with maximal deformation in the mid-flexed position.

scholarly journals Effects of wrist extension on median nerve and flexor tendon excursions in patients with carpal tunnel syndrome: a case control study

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Chien-Ting Liu ◽  
Dung-Huan Liu ◽  
Chii-Jen Chen ◽  
You-Wei Wang ◽  
Pao-Sheng Wu ◽  
...  
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Healthy Volunteers ◽  
Median Nerve ◽  
Carpal Tunnel ◽  
Flexor Tendon ◽  
Wrist Extension ◽  
Finger Flexion ◽  
Tunnel Syndrome ◽  
Healthy Participants ◽  
Tendon Excursion

Abstract Background Reduced gliding ability of the median nerve in the carpal tunnel has been observed in patients with carpal tunnel syndrome (CTS). The purpose of this study was to evaluate the gliding abilities of the median nerve and flexor tendon in patients with CTS and healthy participants in the neutral and 30° extended positions of the wrist and to compare the gliding between the finger flexion and extension phases. Methods Patients with CTS and healthy participants were consecutively recruited in a community hospital. All the subjects received the Boston CTS questionnaire, physical examinations, nerve conduction study (NCS), and ultrasonography of the upper extremities. Duplex Doppler ultrasonography was performed to evaluate the gliding abilities of the median nerve and flexor tendon when the subjects continuously moved their index finger in the neutral and 30° extension positions of the wrist. Results Forty-nine patients with CTS and 48 healthy volunteers were consecutively recruited. Significant differences in the Boston CTS questionnaire, physical examination and NCS results and the cross-sectional area of the median nerve were found between the patients and the healthy controls. The degree of median nerve gliding and the ratio of median nerve excursion to flexor tendon excursion in the CTS group were significantly lower than those in the healthy control group in both the neutral and 30° wrist extension positions. Significantly increased excursion of both the median nerve and flexor tendon from the neutral to the extended positions were found in the CTS group. The ratio of median nerve excursion to flexor tendon excursion was significantly higher in the finger flexion phase than in the extended phase in both groups, and this ratio had mild to moderate correlations with answers on the Boston CTS Questionnaire and with the NCS results. Conclusions Reduced excursion of the median nerve was found in the patients with CTS. The ratio of median nerve excursion to flexor tendon excursion was significantly lower in the patients with CTS than in the healthy volunteers. The median nerve excursion was increased while the wrist joint was extended to 30° in the patients with CTS. Wrist extension may be applied as part of the gliding exercise regimen for patients with CTS to improve median nerve mobilization.

Clinical Update: Assessing Maximum Medical Improvement in Carpal Tunnel Syndrome

2003 ◽  
Vol 8 (4) ◽  
pp. 4-5
Author(s):  
Christopher R. Brigham ◽  
James B. Talmage
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Carpal Tunnel ◽  
Proper Time ◽  
Carpal Tunnel Release ◽  
Hand Function ◽  
Factors Affecting ◽  
Early Results ◽  
Medical Evaluation ◽  
Nerve Recovery ◽  
Tunnel Syndrome

Abstract Permanent impairment cannot be assessed until the patient is at maximum medical improvement (MMI), but the proper time to test following carpal tunnel release often is not clear. The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) states: “Factors affecting nerve recovery in compression lesions include nerve fiber pathology, level of injury, duration of injury, and status of end organs,” but age is not prognostic. The AMA Guides clarifies: “High axonotmesis lesions may take 1 to 2 years for maximum recovery, whereas even lesions at the wrist may take 6 to 9 months for maximal recovery of nerve function.” The authors review 3 studies that followed patients’ long-term recovery of hand function after open carpal tunnel release surgery and found that estimates of MMI ranged from 25 weeks to 24 months (for “significant improvement”) to 18 to 24 months. The authors suggest that if the early results of surgery suggest a patient's improvement in the activities of daily living (ADL) and an examination shows few or no symptoms, the result can be assessed early. If major symptoms and ADL problems persist, the examiner should wait at least 6 to 12 months, until symptoms appear to stop improving. A patient with carpal tunnel syndrome who declines a release can be rated for impairment, and, as appropriate, the physician may wish to make a written note of this in the medical evaluation report.

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