Hsiu-Yun Hsu

The motion analysis system and goniometry of the finger joints

The application of a video-based motion analysis system for goniometry of finger joints during measurement of the fingertip motion area has been assessed. The results indicate that the motion analysis system is reliable for angular measurements of finger joints that are comparable with those obtained by conventional goniometer. The advantages of using the motion analysis system is that it can record and show the changes in angle of all finger joints continuously during finger motion.

THE USE OF THE MOTION ANALYSIS SYSTEM FOR EVALUATION OF LOSS OF MOVEMENT IN THE FINGER

We have used the motion analysis system to measure loss of finger movement after injury. The motion analysis system can provide information about the dynamic angular changes of each finger joint and the fingertip motion area for the injured finger. The latter can be used to calculate the percentage of fingertip motion area preserved. A stiff finger may show limited fingertip motion area with the finger joints tending to flex and extend together.

Jar-opening challenges. Part 2: estimating the force-generating capacity of thumb muscles in healthy young adults during jar-opening tasks.

Abstract This study discusses the force-generating capacity of thumb muscles during jar-opening tasks using two grip patterns: the power grip and the precision grip. This study develops a three-dimensional biomechanical model of the thumb to predict muscle forces in jar-opening activities based on external forces measured by a custom-designed jar device. Ten healthy subjects participated in the study. Each participant turned a jar lid of 66 mm diameter counterclockwise with maximal effort and preferred speed using both grip patterns. The average normal and tangential forces applied by the thumb to the jar lid show that the normal force is the primary contributive force for opening a jar. This normal force is approximately three times the tangential force. Muscular force-generating capacity measurements show that the major active muscles during a jar-opening activity for both grips include the flexor pollicis longus, flexor pollicis brevis, abductor pollicis brevis, adductor pollicis, and opponens pollicis. The total muscle force ratios for the precision grip and power grip with respect to externally applied forces are 5.6 and 4.7 respectively. These ratios indicate that the power grip pattern produces less muscle force per unit of external applied load. The technique proposed in this study provides a proper apparatus and model for measuring three-dimensional loads and estimating the force-generating capacity of each muscle and tendon of the thumb during jar-opening tasks.

Secondary procedures following digital replantation and revascularisation

In this retrospective study, 79 digits of 55 patients received 102 secondary procedures following replantation. We divided the procedures into two groups, occurring before or after 2 months following replantation. The procedures in the early group were mainly for soft tissue coverage (92%), and those in that late group were mainly for tendon (67%) to improve function. Factors associated with higher incidence of early secondary procedures included multiple-finger injury, avulsion or degloving injury and level of injury proximal to zone III in finger replantation (p<0.05). However, younger patients and those with proximal level replantation in fingers had more late secondary procedures (p<0.05). Flexor tenolysis procedure significantly improved the digital function after replantation (p<0.05).

The validity of using a video-based motion analysis system for measuring maximal area of fingertip motion and angular variation

Abstract The aim of the study was to verify the application of a three-dimensional video motion analysis system to evaluate maximal fingertip motion area and angular variation of the hand by comparison and correlation with videofluoroscopic analysis. Eight normal subjects were recruited in this study. The maximal motion area of the fingertip and the angles of the metacarpal phalangeal (MP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints in performing five sequential postures for functional evaluation of the hand were measured using a video motion analysis system and a fluoroscopy system respectively. The results indicated that the intraclass correlation coefficient (ICC) of the calculated maximal fingertip motion area between the two methods was 0.9597. The ICC for total active motion (TAM) measurements of three finger joints was 0.940 between the surface and bony landmarks by fluoroscopy, 0.952 between the surface landmarks from fluoroscopy and motion analysis, and 0.927 between the bony landmark from fluoroscopy and surface markers from motion analysis. The ICC for angular measurements between three different paired assessments was 0.9650, 0.8896 and 0.8799 for the MP, PIP and DIP joints respectively. The results indicate that motion analysis is a practical method for assessing impairment of the hand.

Distraction lengthening of a replanted digit.

The Ilizarov technique was used to lengthen a replanted middle finger on a musicians left hand. Bone consolidation was achieved in 6 months without the need for a bone graft. The elongated digit has good sensibility, appropriate stability, and sufficient length, which were essential for a good performance in her profession. The unique indication to apply the callus distraction technique in such a special condition was described, and the relative merits of other treatment alternatives were discussed.

Is progressive early digit mobilization intervention beneficial for patients with external fixation of distal radius fracture? A pilot randomized controlled trial:

Objective: To investigate whether progressive early digit mobilization resulted in better outcomes for hand stiffness and related functional results, as well as the effects on the bone healing process. Design: Prospective, pilot randomized controlled trial. Setting: A university hospital in southern Taiwan. Participants: Twenty-two patients with distal radius fracture randomized into two groups: early digit mobilization or control. Interventions: The intervention group received 45 minutes per treatment session and three sessions per week until the external fixator was removed 6 weeks after fracture. The control group received usual home programmes. After removing fixators, both groups received regular rehabilitation programmes until 12 weeks after surgery. Main measures: Hand strength, dexterity and functional outcomes were obtained using a dynamometer, Purdue pegboard and self-report assessment, respectively, and X-rays of the distal radius were taken to reveal bone healing 1, 3, 6 and 12 weeks after surgery. A motion tracking system measured various kinematic parameters. Results: The recovery rates between the groups showed statistically significant differences in both thumb workspace (81.55% vs. 69.54%, P = 0.04) and finger workspace (89.22% vs. 59.97%, P = 0.03) 12 weeks after injury. However, no statistical differences were found in finger dexterity, strength and self-reported outcomes. The radiographic assessment showed no significant differences between the groups for radial inclination, radial height and volar tilt throughout the examinations. Conclusions: The findings suggest that early rehabilitative intervention for digits is applicable for distal radius fracture treatment, and does not produce additional bone deformities.

Diagnosis From Functional Perspectives: Usefulness of a Manual Tactile Test for Predicting Precision Pinch Performance and Disease Severity in Subjects With Carpal Tunnel Syndrome

OBJECTIVES To investigate how the severity levels revealed in a nerve conduction study (NCS) affect the results of the Manual Tactile Test (MTT) for patients with carpal tunnel syndrome (CTS), and to examine the relationships between the results of the MTT and precision pinch performance. DESIGN Case-control studies. SETTING Hospital and local community. PARTICIPANTS Patients with CTS (N=70) with 119 affected hands were studied. A control group matched by age, sex, and hand dominance was also recruited. INTERVENTION Not applicable. MAIN OUTCOME MEASURES CTS severity was determined based on NCS findings. The MTT, traditional sensory tests, and precision pinch performance were used to examine the functional sensory status of the hand from different perspectives. RESULTS The patients with CTS exhibited deterioration in all of the sensibility tests (P<.001). The results showed that the MTT could classify subgroups of severity in CTS (P<.001). A moderate correlation was found between the results of the MTT and precision pinch performance (r=.526-.585, P<.001). Multiple linear regression analysis showed that the MTT results were useful indicators for predicting precision pinch performance and differentiating severity in subjects with CTS (r(2)=.376 and .323, respectively). CONCLUSIONS The findings indicate that the MTT could be a valid and useful assessment for hand sensibility and prehensile pinch performance in patients with CTS.

Feasibility of a Novel Functional Sensibility Test as an Assisted Examination for Determining Precision Pinch Performance in Patients with Carpal Tunnel Syndrome

To understand the feasibility of a novel functional sensibility test for determining precision pinch performance in patients with carpal tunnel syndrome, this study investigates the validity, sensitivity and specificity of functional sensibility derived from a pinch-holding-up activity (PHUA) test. Participants include 70 clinically defined carpal tunnel syndrome (CTS) patients with 119 involved hands and 70 age- and gender-matched controls. To examine the discriminating ability of the functional sensibility test, the differences in the ability of pinch force adjustments to the inertial load of handling object between CTS and control subjects are analyzed. The results of functional sensibility are correlated with the severity of CTS to establish concurrent validity. The receiver operating characteristic (ROC) curve is constructed to demonstrate the accuracy of the proposed test. The functional sensibility score significantly discriminates the patients and control groups (respectively, 12.94±1.72 vs. 11.51±1.15N in peak pinch force (FPPeak), p<0.001; 2.92±0.41 vs. 2.52±0.24 in force ratio, p<0.001) and is moderately correlated (r = 0.42–0.54, p<0.001) with the results of traditional sensibility tests (touch-pressure threshold and two-point discrimination test). In addition, there is a statistical difference in the results of functional sensibility (p<0.001) among the subgroups of CTS severity based on electrophysiological study. The sensitivity and specificity are 0.79 and 0.76, respectively, for the functional sensibility test. The areas under the ROC curve are 0.85 and 0.80 for the force ratio and FPPeak, respectively. In conclusion, the functional sensibility test could be feasibly used as a clinical tool for determining both the sensibility and precision pinch performance of hands for the patients with CTS.

Impact of Distal Median Neuropathy on Handwriting Performance for Patients with Carpal Tunnel Syndrome in Office and Administrative Support Occupations

Purpose This study investigates the handwriting performance of patients with carpal tunnel syndrome (CTS) and healthy controls in office and administrative support occupations, adopting both biomechanical and functional perspectives. This work also explores how surgical intervention altered the performance of the CTS patients. Methods Fourteen CTS patients and 14 control subjects were recruited to complete a self-reported survey and participate in sensory tests, hand strength, dexterity and handwriting tasks using a custom force acquisition pen along with motion capture technology. Based on the results of these, the sensory measurements, along with functional and biomechanical parameters, were used to determine the differences between the groups and also reveal any improvements that occurred in the CTS group after surgical intervention. Results The CTS patients showed significantly poorer hand sensibility and dexterity than the controls, as well as excessive force exertion of the digits and pen tip, and less efficient force adjustment ability during handwriting. After surgery and sensory recovery, the hand dexterity and pen tip force of the CTS patients improved significantly. The force adjustment abilities of the digits also increased, but these changes were not statistically significant. Conclusions This study provides the objective measurements and novel apparatus that can be used to determine impairments in the handwriting abilities of office or administrative workers with CTS. The results can also help clinicians or patients to better understand the sensory-related deficits in sensorimotor control of the hand related to CTS, and thus develop and implement more suitable training or adaptive protocols.