Effects of an assist-as-needed equipped Tenodesis-Induced-Grip Exoskeleton Robot (TIGER) on upper limb function in patients with chronic stroke.

BACKGROUND: The original version of the Tenodesis-Induced-Grip Exoskeleton Robot (TIGER) significantly improved the motor and functional performance of the affected upper extremity of chronic stroke patients. The assist-as-needed (AAN) technique in robot-involved therapy is widely favored for promoting patient active involvement, thereby fostering motor recovery. However, the TIGER lacked an AAN control strategy, which limited its use in different clinical applications. The present study aimed to develop and analyze the training effects of an AAN control mode to be integrated into the TIGER, to analyze the impact of baseline patient characteristics and training paradigms on outcomes for individuals with chronic stroke and to compare training effects on the upper limb function between using the AAN-equipped TIGER and using the original prototype. METHODS: This was a single-arm prospective interventional study which was conducted at a university hospital. In addition to 20 min of regular task-specific motor training, each participant completed a 20-min robotic training program consisting of 10 min in the AAN control mode and 10 min in the functional mode. The training sessions took place twice a week for 9 weeks. The primary outcome was the change score of the Fugl-Meyer Assessment of the Upper Extremity (FMA-UE), and the secondary outcomes were the change score of the Box and Blocks Test (BBT), the amount of use (AOU) and quality of movement (QOM) scales of the Motor Activity Log (MAL), the Semmes-Weinstein Monofilament (SWM) test, and the Modified Ashworth Scale (MAS) for fingers and wrist joints. The Generalized Estimating Equations (GEE) and stepwise regression model were used as the statistical analysis methods. RESULTS: Sixteen chronic stroke patients completed all steps of the study. The time from stroke onset to entry into the trial was 21.7 ± 18.9 months. After completing the training with the AAN-equipped TIGER, they exhibited significant improvements in movement reflected in their total score (pre/post values were 34.6 ± 11.5/38.5 ± 13.4) and all their sub-scores (pre/post values were 21.5 ± 6.0/23.3 ± 6.5, 9.5 ± 6.2/11.3 ± 7.2, and 3.6 ± 1.0/3.9 ± 1.0 for the shoulder, elbow, and forearm sub-category, the wrist and hand sub-category, and the coordination sub-category, respectively) on the FMA-UE (GEE, p < 0.05), as well as their scores on the BBT (pre/post values were 5.9 ± 6.5/9.5 ± 10.1; GEE, p = 0.004) and the AOU (pre/post values were 0.35 ± 0.50/0.48 ± 0.65; GEE, p = 0.02). However, the original TIGER exhibited greater improvements in their performance on the FMA-UE than the participants training with the AAN-equipped TIGER (GEE, p = 0.008). The baseline score for the wrist and hand sub-category of the FMA-UE was clearly the best predictor of TIGER-mediated improvements in hand function during the post-treatment assessment (adjusted R2 = 0.282, p = 0.001). CONCLUSIONS: This study developed an AAN-equipped TIGER system and demonstrated its potential effects on improving both the function and activity level of the affected upper extremity of patients with stroke. Nevertheless, its training effects were not found to be advantageous to the original prototype. The baseline score for the FMA-UE sub-category of wrist and hand was the best predictor of improvements in hand function after TIGER rehabilitation. Clinical trial registration ClinicalTrials.gov, identifier NCT03713476; date of registration: October19, 2018. https://clinicaltrials.gov/ct2/show/NCT03713476.

Are the sensorimotor control capabilities of the hands the factors influencing hand function in people with schizophrenia?

BACKGROUND: Previous works reported people with schizophrenia experienced inferior hand functions which influence their daily participation and work efficiency. Sensorimotor capability is one of indispensable elements acting in a well-executed feed-forward and feedback control loop to contribute to hand performances. However, rare studies investigated contribution of sensorimotor ability to hand functions for people with schizophrenia. This study aimed to explore hand function in people with schizophrenia based on the perspective of the sensorimotor control capabilities of the hands. METHODS: Twenty-seven people at the chronic stage of schizophrenia were enrolled. The following assessment tools were used: the Purdue Pegboard Test (PPT) and the VALPAR Component Work Sample-8 (VCWS 8) system for hand function; the Self-Reported Graphic version of the Personal and Social Performance (SRG-PSP) scale for functionality; and the Semmes-Weinstein Monofilaments (SWM), the pinch-holding-up-activity (PHUA) test and the Manual Tactile Test (MTT) for the sensory and sensorimotor parameters. The Clinical Global Impression-Severity (CGI-S) scale and the Extrapyramidal Symptom Rating Scale (ESRS) were used to grade the severity of the illness and the side-effects of the drugs. Spearman's rank correlation coefficient was used to analyze associations among hand function, functionality, and sensorimotor capabilities. A multiple linear regression analysis was used to identify the determinants of hand function. RESULTS: The results indicated that both hand function and sensorimotor capability were worse in people with schizophrenia than in healthy people, with the exception of the sensory threshold measured with the SWM. Moreover, the sensorimotor abilities of the hands were associated with hand function. The results of the regression analysis showed that the MTT measure of stereognosis was a determinant of the PPT measure of the dominant hand function and of the performance on the VCWS 8, and that the ESRS and the MTT measure of barognosis were determinants of the performance on the assembly task of the PPT. CONCLUSIONS: The findings suggested that sensorimotor capabilities, especially stereognosis and barognosis, are crucial determinants of hand function in people with schizophrenia. The results also revealed that the side effects of drugs and the duration of the illness directly affect hand function. CLINICAL TRAIL REGISTRATION: ClinicalTrials.gov , identifier NCT04941677, 28/06/2021.

Jigless Knotless Internal Brace Versus Other Minimal Invasive Achilles Tendon Repair Techniques in Biomechanical Testing Simulating the Progressive Rehabilitation Protocol.

The jigless knotless internal brace surgery (JKIB), an alternative method for minimal invasive surgery (MIS) repair of acute Achilles tendon rupture, has advantages of preventing sural-nerve injury in MIS and superficial wound infection in open surgery, as previous clinical research demonstrates. However, no comparative study on the biomechanical performance between JKIB and other MIS techniques has been reported until now. In this study, 50 fresh porcine Achilles tendons were used to compare the JKIB with open surgery (two-stranded Krachow suture) with other MIS techniques, including Percutaneus Achilles Repair System (PARS), Speedbridge (SB), and Achillon Achilles Tendon Suture System (ACH), using a biomechanical testing with cyclic loading at 1 Hz. This test was used to simulate a progressive rehabilitation protocol where 20 to 100 N was applied in the first 250 cycles, followed by 20 to 190 N in the second 250 cycles, and then 20 to 369 N in the third 250 cycles. The cyclic displacement after 10, 100 and 250 cycles were recorded. The survived cycles were defined as a sudden drop in measured load. In survived cycles, the JKIB group (552.3 ± 72.8) had significantly higher cycles than the open, PARS, and ACH groups (204.3 ± 33.3, 395.9 ± 96.0, and 397.1 ± 80.9, respectively, p < .01) as analyzed by post hoc analysis, but no significant difference as compared with the SB group (641.6 ± 48.7). In cyclic displacement after 250 cyclic loadings, the JKIB group (11.29 ± 1.29) showed no significant difference as compared with PARS, SB, and ACH groups (12.21 ± 1.18, 9.80 ± 0.80, and 11.57 ± 1.10 mm, respectively) and significant less displacement than the open group (14.50 ± 1.85, p < .01). These findings suggest that JKIB could be an option for acute Achilles tendon repair in the MIS fashion due to no larger cyclic elongation compared with other MIS techniques.

Pen-grip kinetics in children with and without handwriting difficulties.

INTRODUCTION: Handwriting difficulty (HD) is a widely discussed issue. Previous researchers have revealed many valuable kinematics related to the handwriting performance. However, a clear understanding of the kinetics of handwriting performance in children with HD is still lacking. Therefore, this study investigated the writing performance of children with HD via a force acquisition pen (FAP), which detects the force applied from the digits and pen tip. METHODS: Data from 64 school-age children were divided into control (36 children without HD; mean age: 7.97 years) and HD (28 children with HD; mean age: 8.67 years) groups. The participants were asked to perform a tracing task using the FAP at their usual writing pace. RESULTS: Compared with the control group, the HD group had significantly less pen-tip force, an average amount of force (in-air) from all three digits, higher force variations (whole task) in the index finger, less force fluctuations with the index and middle fingers and a smaller force ratio. CONCLUSION: The findings of this study suggest that an understanding of the handwriting kinetics and the role of digits in handwriting may be crucial for further planning strategies for handwriting training for children with HD.

A Novel and Clinically Feasible Instrument for Quantifying Upper Limb Muscle Tone and Motor Function via Indirect Measure Methods.

OBJECTIVE: Quantifying muscle tone is often based on a tester's subjective judgment in clinical settings. There is, however, a lack of suitable tools that can be used to objectively assess muscle tone. This study thus introduces a reliable, clinically-feasible device, called the Arm Circumference Motor Evaluation System (ACMES), for quantifying the muscle tone of upper limbs without using mechanical torque transducers. METHODS: While the ACMES conducts continuously passive arm circumduction motions, the voltage and current of the driving motor is transduced into torque values via a least square approximation. A torque sensor and springs with different spring constants were used for the validity and reliability test in the first part of this study. Fifteen healthy adults and two patients who had experienced a stroke participated in the second part, which was a clinical experiment used to examine the in-vivo test-retest reliability and to explore the inspection differences between healthy and patient participants. RESULTS: The results showed that the ACMES has high validity (R2: ~0.99) and reliability (R2: 0.96~0.99). The reliability of the ACMES used on human subjects was acceptable (R2: 0.83~0.85). The various muscle tone patterns could be found among healthy and stroke subjects via the ACMES. CONCLUSION: Clinically, abnormal muscle tone, which seriously affects motion performance, will be found in many diagnoses, such as stroke or cerebral palsy. However, objectively and feasibly measuring abnormal tone in modern clinical settings is still a challenging task. Thus, the ACMES was developed and tested to verify its feasibility as a measurement system for detecting the mechanical torque associated with muscle tone.

Jigless knotless internal brace versus other open Achilles tendon repairs using a progressive rehabilitation protocol: a biomechanical study.

BACKGROUND: The jigless knotless internal brace surgery (JKIB), a modified minimal invasive surgery (MIS) for acute Achilles tendon injury, has advantages of preventing sural-nerve injury in MIS and superficial wound infection in open surgery, as demonstrated in previous clinical research. However, to date, biomechanical testing has not yet been validated. MATERIALS AND METHODS: Sixty fresh porcine Achilles tendons were used to compare the JKIB with other open surgery techniques, the four-stranded Krackow suture (4sK) and the triple-bundle suture (TBS) in biomechanical testing with cyclic loading set at 1 Hz. This approach simulated a progressive rehabilitation protocol where 20-100 N was applied in the first 1000 cycles, followed by 20-190 N in the second 1000 cycles, and then 20-369 N in the third 1000 cycles. The cycles leading to repair gaps of 2 mm, 5 mm, and 10 mm were recorded. The survival cycles were defined as repair gap of 10 mm. RESULTS: With respect to survival cycles, a significant difference was found among the three groups, in which the TBS was the most robust, followed by the JKIB and the 4sK, where the mean survived cycles were 2639.3 +/- 263.55, 2073.6 +/- 319.92, and 1425.25 +/- 268.96, respectively. Significant differences were verified via a post hoc analysis with the Mann-Whitney U test after the Bonferroni correction (p < 0.017). CONCLUSIONS: The TBS was the strongest suture structure in acute Achilles tendon repair. However, the JKIB could be an option in acute Achilles tendon repair with the MIS technique due to it being more robust than the 4sK, which has been typically favored for use in open repair.

The effect of task complexity on handwriting kinetics.

BACKGROUND.: Knowledge regarding the relationship between writing kinetics and the difference among writing tasks is limited. PURPOSE.: This study examined the differences in handwriting performance when doing tasks with different levels of challenge from both temporal and kinetic perspectives among children in four different age groups. METHOD.: The cross-sectional design introduced a force-acquisition pen to detect differences of pen grip and writing kinetics among 170 school-age children doing writing tasks at different difficulty levels. Data were obtained on the force information of the digits and pen tip and the kinetic parameters to examine the coordination-and-control mechanism between the digits and pen. Statistical analyzes were carried out to indicate the differences in writing performance among groups and tasks. FINDINGS.: Statistical differences in the pen-grip forces, force fluctuation, and force ratio between grip and pen-tip forces were found when performing different writing tasks and among different age groups. IMPLICATIONS.: The study provides an alternative method to explore how writing performance among school-age children can vary according to the difficulty of the writing tasks.

Dynamic weight bearing analysis is effective for evaluation of tendinopathy using a customized corridor with multi-directional force sensors in a rat model.

Few studies discuss kinetic changes in tendinopathy models. We propose a customized corridor to evaluate dynamic weight bearing (DWB) and shearing forces. Sixty rats were randomly given ultrasound-assisted collagenase injections (Collagenase rats) or needle punctures (Control rats) in their left Achilles tendons, and then evaluated 1, 4, and 8 weeks later. The Collagenase rats always had significantly (p < 0.001) higher histopathological and ultrasound feature scores than did the Controls, significantly lower DWB values in the injured than in the right hindlimbs, and compensatorily higher (p < 0.05) DWB values in the contralateral than in the left forelimbs. The injured hindlimbs had lower outward shearing force 1 and 4 weeks later, and higher (p < 0.05) push-off shearing force 8 weeks later, than did the contralateral hindlimbs. Injured Control rat hindlimbs had lower DWB values than did the contralateral only at week 1. The Collagenase rats had only lower static weight bearing ratios (SWBRs) values than did the Controls at week 1 (p < 0.05). Our customized corridor showed changes in DWB compatible with histopathological and ultrasound feature changes in the rat tendinopathy model. The hindlimb SWBRs did not correspond with any tendinopathic changes.

Comprehension of handwriting development: Pen-grip kinetics in handwriting tasks and its relation to fine motor skills among school-age children.

BACKGROUND/AIM: Numerous tools have been developed to evaluate handwriting performances by analysing written products. However, few studies have directly investigated kinetic performances of digits when holding a pen. This study thus attempts to investigate pen-grip kinetics during writing tasks of school-age children and explore the relationship between the kinetic factors and fine motor skills. METHODS: This study recruited 181 children aged from 5 to 12 years old and investigated the effects of age on handwriting kinetics and the relationship between these and fine motor skills. The forces applied from the digits and pen-tip were measured during writing tasks via a force acquisition pen, and the children's fine motor performances were also evaluated. RESULTS: The results indicate that peak force and average force might not be direct indicators of handwriting performance for normally developing children at this age. Younger children showed larger force variation and lower adjustment frequency during writing, which might indicate they had poorer force control than the older children. Force control when handling a pen is significantly correlated with fine motor performance, especially in relation to the manual dexterity. CONCLUSIONS/SIGNIFICANCE OF THE STUDY: A novel system is proposed for analysing school-age children's force control while handwriting. We observed the development of force control in relation to pen grip among the children with different ages in this study. The findings suggested that manipulation skill may be crucial when children are establishing their handwriting capabilities.

Developing functional workspace for the movement of trunk circumduction in healthy young subjects: a reliability study.

BACKGROUND: The lumbar range of motion has traditionally been used to assess disability in patients with low back disorders. Controversy exists about how movement ranges in static positions or in a single straight plane is related to the functional status of the patients. The trunk circumduction, as the result of neuromuscular coordination, is the integrated movements from three dimensions. The functional workspace stands for the volume of movement configuration from the trunk circumduction and represents all possible positions in three dimensions. By using single quantitative value, the functional workspace substitutes the complicated joint linear or angular motions. The aim of this study is to develop the functional workspace of the trunk circumduction (FWTC) considering possible functional positions in three dimensional planes. The reliability of the trunk circumduction is examined. METHODS: Test-retest reliability was performed with 18 healthy young subjects. A three-dimensional (3-D) Motion Analysis System was used to record the trunk circumduction. The FWTC was defined and calculated based on the volume of the cone that was formed as the resultant scanned area of markers, multiplied by the length of the body segment. The statistical analysis of correlation was performed to describe the relation of maximal displacements of trunk circumduction and straight planes: sagittal and coronal. RESULTS: The results of this study indicate that the movement of trunk circumduction measured by motion analysis instruments is a reliable tool. The ICC value is 0.90-0.96, and the means and standard deviations of the normalized workspace are: C7 0.425 (0.1162); L1 0.843 (0.2965); and knee 0.014 (0.0106). Little correlations between the maximal displacement of trunk circumduction and that of straight planes are shown and therefore suggest different movement patterns exist. CONCLUSIONS: This study demonstrates high statistical reliability for the FWTC, which is important for the potential development as the functional assessment technique. The FWTC provides a single integrated value to represent angular and linear measurements of different joints and planes. Future study is expected to carry out the FWTC to evaluate the amount of workspace for the functional status of patients with low back injuries or patients with spinal surgery.