Movement pattern and upper extremity muscle activation during fast and slow continuous steering movement.

Continuous steering movement (CSM) is an essential component of the upper extremity (UE) task during vehicle driving, and could be a suitable candidate for multi-joint rehabilitation programs for patients with UE disabilities. This study aims to evaluate the UE muscle activation during CSM and how the rotating speed and direction affect CSM's kinematic and kinetic performance. Surface electromyography (EMG), hand contact information, and steering torque were measured under fast (180°/s) and slow (60°/s) constant-velocity CSM to reveal the activation of shoulder and elbow muscles, temporal characteristics, and force exertion during the stance and swing phases of a CSM cycle. Data from 24 normal young adults showed that shorter contact duration but higher force exertion occurred in the hand moving in an outward steering direction during only fast CSM in either the clockwise (CW) or counterclockwise (CCW) direction. During a steering cycle (either fast or slow speed), the triceps brachii, sternal part of the pectoralis major (PS), and posterior deltoid play major roles in generating steering torque in the CW direction of the CSM. In contrast, the PS, clavicular part of the pectoralis major (PC), and anterior deltoid (AD) largely contribute to torque generation during the CCW CSM. During the swing phase of CSM, AD, PC, and PS are the major muscles that move the hand for the next grasping of the steering wheel in all four conditions. Using the mean activation profiles of the major contributing muscles, the functional roles of these elbow and shoulder muscles were analyzed and are discussed herein. These findings help us to further understand the activation patterns of UE muscles and the kinematic and kinetic changes during two rotating directions and two speeds of CSM, and suggest important implications for future practice in clinical training.

Effects of transcranial direct current stimulation on improving performance of delayed- reinforcement attentional set-shifting tasks in attention-deficit/hyperactivity disorder rat model.

Behavioral flexibility (or set-shifting), which is regulated by the prefrontal cortex (PFC), is often impaired in patients with attention-deficit/hyperactivity disorder (ADHD), which is characterized by poor inhibitory control and reinforcement learning. Transcranial direct current stimulation (tDCS) has been proposed as a means of noninvasive brain stimulation and a potential therapeutic tool for modulating behavioral flexibility. Animal studies can pave the way to know if tDCS application can potentially benefit rule- and goal-based activities in ADHD. Spontaneously hypertensive rats (SHRs) and inbred Wistar-Kyoto (WKY) rats were used as an animal model of ADHD and controls, respectively, and their strategy set-shifting abilities, including initial discrimination, set-shifting, and reversal learning tasks under 0-s or 15-s reinforcer delivery delay conditions, were evaluated. The tDCS treatment had a limited effect on the performance of the SHRs and WKY rats in initial discrimination task under 0-s delay condition. Under the 15-s delay condition, the SHRs had longer lever-press reaction times and/or more trial omissions than the WKY rats did when completing set-shifting and reversal-learning tasks. Among the SHRs, tDCS treatment improved the rats' reaction times and/or reduced their trial omissions in the set-shifting and reversal-learning tasks. Although tDCS may improve delayed reinforcement learning set-shifting performance in SHRs, further studies are required to clarify the responsible mechanism.

Association between Fear of Falling and Seven Performance-Based Physical Function Measures in Older Adults: A Cross-Sectional Study.

Fear of falling (FOF), a common phenomenon among older adults, may result in adverse health consequences. The strength of the association between FOF and physical function among older adults has not been well compared in previous studies. Therefore, a cross-sectional study was performed on 105 older adults to determine and compare the strength of the association between FOF and seven common physical function measures. After controlling for age, logistic regression models were fitted for each physical function measure. According to odds ratios, the Berg Balance Scale (BBS), Short Physical Performance Battery, gait speed, and Timed Up & Go Test were associated with the identification of FOF. Based on a c-statistic value of 0.76, the BBS, a common and quick assessment of functional balance tasks, was found to be able to distinguish between fearful and non-fearful older adults. Interventions targeted to improve lower-extremity physical functions, especially functional balance ability, may help prevent or delay the adverse consequences of FOF.

Algorithm to Improve Resuscitation Outcomes in Patients With Traumatic Out-of-Hospital Cardiac Arrest.

BACKGROUND: This study proposed an algorithm to improve resuscitation outcomes in the emergency department (ED) for patients with traumatic out-of-hospital cardiac arrest (TOHCA). We also performed a retrospective chart review of patient outcomes before and after implementing the algorithm and sought to define factors that might influence patient outcomes. METHODS: In September 2018, we implemented an algorithm for patients with TOHCA. This algorithm rapidly identifies possible causes of TOHCA and recommends appropriate interventions. We retrospectively reviewed the outcomes of all patients with TOHCA during a five-year period (comprising periods before and after the algorithm) and compared the results before and after the implementation of the algorithm. RESULTS: After this algorithm was implemented, the use of the ED interventions of blood transfusion, placement of a large-bore central venous catheter, and thoracostomy increased significantly. The rate of return of spontaneous circulation (ROSC) also increased (before vs. after: ROSC: 23.6% vs. 41.5%, P = 0.035). Regarding hospital admission and survival to hospital discharge, we observed the trend of increment (hospital admission: 18.2% vs. 24.6%, P = 0.394; survival to hospital discharge: 0.0% vs. 4.6%, P = 0.107). Admitted patients exhibited a higher end-tidal CO2 level during resuscitation than nonadmitted patients [admitted vs. nonadmitted: 41.5 (33.3-52.0) vs. 12.0 (7.5-18.8), P = 0.001]. CONCLUSION: Our algorithm prioritizes the three major treatable causes of TOHCA: impedance of venous return, hypovolemia, and hypoxia. We found that rate of ROSC increased with the increasing implementation of the ED interventions recommended by the algorithm.

Alternative Motor Task-Based Pattern Training With a Digital Mirror Therapy System Enhances Sensorimotor Signal Rhythms Post-stroke.

Mirror therapy (MT) facilitates motor learning and induces cortical reorganization and motor recovery from stroke. We applied the new digital mirror therapy (DMT) system to compare the cortical activation under the three visual feedback conditions: (1) no mirror visual feedback (NoMVF), (2) bilateral synchronized task-based mirror visual feedback training (BMVF), and (3) reciprocal task-based mirror visual feedback training (RMVF). During DMT, EEG recordings, including time-dependent event-related desynchronization (ERD) signal amplitude in both mu and beta bands, were obtained from the standard C3 (ispilesional hemisphere, IH), C4 (contralesional hemisphere, CH), and Cz scalp sites (supplementary motor area, SMA). The entire ERD curve was separated into three time-phases: P0 (-2 to 0 s), P1 (0 to 2 s), and P2 (2 to 4 s). Four-way and subsequent repeated-measures analyses of variance were used to examine the effects of group (stroke vs. control group), test condition (NoMVF, BMVF, and RMVF), time-phase (P0, P1, and P2), and brain area (IH, CH, SMA) on the ERD areas (%) in mu and beta bands. For the mu band, generally, ERD areas (%) were larger in the control than in the stroke group. The ERD areas (%) were largest under the RMVF condition, followed by BMVF and NoMVF conditions. Similar results were found in the beta bands. The main effects of group, time-phase, and test condition on the ERD areas (%) were significant for the three brain areas, except the main effect of group in the SMA (Cz) and CH (C4) brain area. The ERD areas (%) were larger in the control than in the stroke group. The ERD area (%) was significantly larger during P1 than during P0 and P2 (ps < 0.02), and during P2 than during P0 (ps < 0.01). The ERD area (%) under the RMVF condition was significantly larger than that under the BMVF condition and NoMVF condition (ps < 0.05). The present study suggests that cortical activation particularly in the SMA (Cz) of the brain increases in the RMVF condition in both healthy subjects and stroke patients. This result supports the hypothesis that stroke patients may benefit from RMVF training.

Force direction and arm position affect contribution of clavicular and sternal parts of pectoralis major muscle during muscle strength testing.

STUDY DESIGN: Cross-sectional study. PURPOSE OF THE STUDY: The study aims to determine the effects of force direction and arm position in differentiating the clavicular (PMc) and sternal (PMs) parts of the pectoralis major (PM) muscle during maximal voluntary isometric contraction (MVIC) to provide basic evidence to support the clinical thinking behind muscle strength testing of PM. METHODS: Nine experimental conditions with 3 force directions of horizontal adduction (+30° oblique, horizontal, and -30° oblique to the transverse plane) and 3 arm rotation positions (0°, 45°, and 90° shoulder external rotation from the transverse plane) were randomly tested for 26 healthy male participants. The MVIC force level was monitored and measured with a fixed dynamometer, and the surface electromyographic (EMG) signals of the PMc, PMs, anterior deltoid, middle deltoid, and latissimus dorsi were collected during the test for each condition. The PMc/PMs EMG ratio and normalized EMG amplitude were used to quantify the contribution of the tested muscles. RESULTS: The MVIC force level significantly declined when the arm's external rotation increased (P < .01; the grand mean decreased from 106.7 N ± 27.8 N to 89.5 N ± 22.6 N). The PMc/PMs EMG ratio showed that the best test condition to differentiate the PMc and PMs was the force direction of +30° oblique to the transverse plane and the 45° arm rotation position. Other muscles contributed less than 40% of their MVIC activity levels, with a higher activation level found in the anterior deltoid muscle (P < .01). CONCLUSIONS: Arm rotation position should be considered as a predominant factor when clinically examining the strength of horizontal adduction movement. All tested conditions failed to fully separate PMc and PMs activation during MVIC and suggested that functional differentiation of the PM might not be applicable to maximal exertion. LEVEL OF EVIDENCE: NA.

Contribution of upper limb muscles to two different gripping styles in elite indoor tug of war athletes.

To investigate characteristic upper limb muscle use between two common tug of war (TOW) gripping styles, 20 elite athletes from two high school TOW teams were recruited. Under conditioned attack pulling (with 90% maximal force) on a tug machine, participants used their own habitual gripping style to pull for five 15-s trials. Force and kinematic measurements showed a significantly better force performance and higher centre-of-gravity tilting angle with the gripping style one than with the gripping style two (GS2) (both p < 0.05). However, an overall higher and more symmetrical muscle activation detected by normalised surface electromyography signal amplitude was found in the GS2 group (both p < 0.05). In both groups, the distal and flexor muscles were more activated than the proximal and extensor muscles, respectively (p < 0.05). Higher co-contraction ratio was found in the wrist joints of the latter arm in both groups (p < 0.05). As higher muscle activation level and co-contraction indicate higher muscle and joint injury incidences, we suggest that gripping style factors should be considered in training to prevent muscle and joint injury. Future study concerning segmental kinematics, ground reaction force, moment arm and muscle endurance during the defence phase are warranted.

Quantitative evaluation for spasticity of calf muscle after botulinum toxin injection in patients with cerebral palsy: a pilot study.

BACKGROUND: Cerebral palsy (CP) is the most common pediatric disease to cause motor disability. Two common symptoms in CP are spasticity and contracture. If this occurred in the ankle plantar flexors of children with CP, it will impair their gait and active daily living profoundly. Most children with CP receive botulinum toxin type A (BoNT-A) injection to reduce muscle tone, but a knowledge gap exists in the understanding of changes of neural and non-neural components of spasticity after injection. The purpose of this study was to determine if our device for quantitative modified Tardieu approach (QMTA) is a valid method to assess spasticity of calf muscles after botulinum toxin injection. METHODS: In this study, we intended to develop a device for quantitative measurement of spasticity in calf muscles based on the modified Tardieu scale (MTS) and techniques of biomedical engineering. Our QMTA measures the angular displacement and resistance of stretched joint with a device that is light, portable and can be operated similar to conventional approaches for MTS. The static (R2), dynamic (R1) and R2-R1 angles derived from the reactive signals collected by the miniature sensors are used to represent the non-neural and neural components of stretched spastic muscles. Four children with CP were recruited to assess the change in spasticity in their gastrocnemius muscles before and 4 weeks after BoNT-A injection. RESULTS: A simulated ankle model validated the performance of our device in measuring joint displacement and estimating the angle of catch. Data from our participants with CP showed that R2 and R2-R1 improved significantly after BoNT-A administration. It indicates both neural and non-neural components of the spastic gastrocnemius muscles improved at four weeks after BoNT-A injection in children with CP. CONCLUSION: Our device for QMTA can objectively measure the changes in spasticity of the gastrocnemius muscle in children with cerebral palsy after BoNT-A injection.

Delayed mirror visual feedback presented using a novel mirror therapy system enhances cortical activation in healthy adults.

BACKGROUND: Mirror visual feedback (MVF) generated in mirror therapy (MT) with a physical mirror promotes the recovery of hemiparetic limbs in patients with stroke, but is limited in that it cannot provide an asymmetric mode for bimanual coordination training. Here, we developed a novel MT system that can manipulate the MVF to resolve this issue. The aims of this pilot study were to examine the feasibility of delayed MVF on MT and to establish its effects on cortical activation in order to understand how it can be used for clinical applications in the future. METHODS: Three conditions (no MVF, MVF, and 2-s delayed MVF) presented via our digital MT system were evaluated for their time-course effects on cortical activity by event-related desynchronization (ERD) of mu rhythm electroencephalography (EEG) during button presses in 18 healthy adults. Phasic ERD areas, defined as the areas of the relative ERD curve that were below the reference level and within -2-0 s (P0), 0-2 s (P1), and 2-4 s (P2) of the button press, were used. RESULTS: The overall (P0 to P2) and phasic ERD areas were higher when MVF was provided compared to when MVF was not provided for all EEG channels (C3, Cz, and C4). Phasic ERD areas in the P2 phase only increased during the delayed-MVF condition. Significant enhancement of cortical activation in the mirror neuron system and an increase in attention to the unseen limb may play major roles in the response to MVF during MT. In comparison to the no MVF condition, the higher phasic ERD areas that were observed during the P1 phase in the delayed-MVF condition indicate that the image of the still hand may have enhanced the cortical activation that occurred in response to the button press. CONCLUSIONS: This study is the first to achieve delayed MVF for upper-limb MT. Our approach confirms previous findings regarding the effects of MVF on cortical activation and contributes additional evidence supporting the use of this method in the future for upper-limb motor training in patients with stroke.

The reproducibility comparison of two intervertebral translation measurements in cervical flexion-extension.

BACKGROUND CONTEXT: The abnormal translations between vertebrae in the sagittal plane are important clues to spinal dysfunction or instability. Several studies have reported significant variability in their translation measurements with no analysis of data reproducibility. PURPOSE: We sought to determine the intra- and interobserver reproducibility of the computer-assisted geometric midplanes and rotation matrix methods in the measurements of intervertebral translations at different motion ranges of cervical flexion-extension in asymptomatic subjects and disc-herniated patients. STUDY DESIGN: A blind, repeated-measure design was applied to determine the reproducibility for intervertebral translation measurements. METHODS: A total of 608 videofluoroscopic image sequences from the different motion ranges of cervical flexion and extension in 38 asymptomatic subjects and 38 disc-herniated patients were digitized for further analysis. RESULTS: The intra- and interobserver reproducibility on measuring the sequential translations were in the acceptable range for geometric midplanes method (average intraclass correlation coefficients [ICCs], 0.860 and 0.806; mean absolute difference [MAD] 0.19 and 0.33 mm) and rotation matrix method (average ICCs, 0.807 and 0.735; MAD, 0.35 and 0.42 mm). There was significantly better reproducibility on the measurements of intervertebral translation for the geometric midplanes method than those of rotation matrix method (p=.001-.040). The absolute mean differences of the translation measurements between two image protocols averaged 11.2% and 10.8% for the asymptomatic subjects and disc-herniated patients, respectively. CONCLUSIONS: Based on these results, both methods demonstrated acceptable reproducibility on the intervertebral translation measurements. The geometric midplanes method involving an averaging effect on the placements of vertebral landmarks and closer to center of rotation might reduce the errors in translation estimations. The rotation matrix protocol simultaneously illustrated horizontal and vertical translation motion despite greater digitizing and/or measurement errors.

Upper limb training using Wii Sports Resort for children with hemiplegic cerebral palsy: a randomized, single-blind trial.

OBJECTIVE: To investigate whether Wii Sports Resort training is effective and if any benefits are maintained. DESIGN: Randomized, single-blind trial. PARTICIPANTS: Sixty-two hemiplegic children with cerebral palsy (6-13 years). INTERVENTION: Experimental group undertook six weeks of home-based Wii Sports Resort training plus usual therapy, while the control group received usual therapy. MAIN MEASURES: Outcomes were coordination, strength, hand function, and carers' perception of hand function, measured at baseline, six, and 12 weeks by a blinded assessor. RESULTS: There was a trend of mean difference (MD) for the experimental group to have more grip strength by six (MD 4.0 N, 95% confidence interval (CI) -0.8 to 8.8, p = 0.10) and 12 (MD 4.1 N, 95% CI -2.1 to 10.3, p = 0.19) weeks, and to have a higher quantity of hand function according to carers' perception by six (MD 4.5 N, 95% CI -0.7 to 9.7, p = 0.09) and strengthened by 12 (MD 6.4, 95% CI 0.6 to 12.3, p = 0.03) weeks than the control group. There was no difference between groups in coordination and hand function by six or 12 weeks. CONCLUSION: Wii training did not improve coordination, strength, or hand function. Beyond the intervention, carers perceived that the children used their hands more.

Gastrocnemius inflexibility on foot progression angle and ankle kinetics during walking.

BACKGROUND: Gastrocnemius inflexibility is a major problem in many orthopedic and neurological patients. Clinically, inflexible gastrocnemius muscles interfere with the performance of functional abilities and associate with many overuse injuries of the lower extremity. The purpose of this study was to investigate the effects of the gastrocnemius inflexibility on the foot progression angle and ankle kinetics during walking. METHODS: There were 50 subjects, 23 patients with the inflexible gastrocnemius and 27 normal subjects, included in this investigation. Participants were asked to walk at two preset cadences of 100 steps/min and 140 steps/min. Data were collected from a motion analysis system and force plates. Kinematic and kinetic variables of gait were computed and analyzed. FINDINGS: Compared with the control group, greater toe-out foot progression angle (P=0.001, effect size=0.314) and knee external rotation (P=0.008, effect size=0.136) were found in the inflexible group during stance phase. Furthermore, significant greater plantarflexion moment (P=0.032, effect size=0.093) and medial ground reaction force (P=0.009, effect size=0.135) during midstance were discovered in the inflexible group. INTERPRETATION: The present results indicate that gastrocnemius inflexibility might bring about the changes in the joint angles, ankle moments and ground reaction forces. The abnormal joint alignment in the lower extremities and greater force upon joint tissue might be significant for the clinical considerations on soft tissue injuries for the patients with inflexible gastrocnemius muscles.

Inhibitory effect of botulinum toxin type A on the NANC system in rat respiratory models of neurogenic inflammation.

This study investigated whether botulinum toxin type A (BTX-A) inhibits respiratory neurogenic inflammation in the non-adrenergic, non-cholinergic (NANC) transmitter system in rats. Neurogenic inflammation models were induced in Sprague Dawley (SD) rats through bilateral cerebral artery occlusion (BCAO) for different times (0, 30 and 60 min) or by stimulation with capsaicin at different doses (5 or 15 g/kg). Pre-Bötzinger Complex-Spikes and the expression of substance P, synaptosomal-associated protein-25 (SNAP-25), and reactive oxygen species (ROS) were detected with or without pretreatment of rats with BTX-A (15 or 30 U/kg). BCAO reduced pre-Bot C spike activity (spike/s) and increased the breath rate (breaths/s) in an unstable pattern in comparison to controls, while pretreatment with BTX-A slightly reduced this phenomenon. Pretreatment with BTX-A inhibited BCAO- or capsaicin-induced increases in expression of SNAP-25, substance P, and ROS in a dose-dependent manner in brainstem and lung tissue. BTX-A exerts a suppressive effect on neurogenic inflammation via non-adrenergic, non-cholinergic transmitters. These results add to the body of evidence elucidating the non-cholinergic effects of BTX-A in the context of neurogenic inflammation.

Analysis of continuous steering movement using a motor-based quantification system.

Continuous steering movement (CSM) of the upper extremity (UE) is an essential component of steering movement during vehicle driving. This study presents an integrated approach to examine the force exertion and movement pattern during CSM. We utilized a concept similar to the isokinetic dynamometer to measure the torque profiles during 180°/s constant-velocity CSM. During a steering cycle, the extremity movement can be divided into stance and swing phases based upon the hand contact information measured from the hand switch devices. Data from twelve normal young adults (six males and six females) showed that there are three typical profiles of force exertion. The two hands exhibit similar time expenditures but with asymmetric force exertions and contact times in both the clockwise (CW) and counterclockwise (CCW) steering cycles. Both hands contribute more force but with less contact time in their outward CSM directions (i.e., CW for the right hand and CCW for the left hand). These findings help us to further understand CSM and have a number of important implications for future practice in clinical training. Considerably more research is required to determine the roles of the various shoulder muscles during CSM at various speeds.

Gastrocnemius tightness on joint angle and work of lower extremity during gait.

BACKGROUND: Muscular tightness is a common clinical musculoskeletal disorder and is regarded as a predisposing factor for muscle injuries. In this study, a two-way mixed design ANOVA was applied to investigate the effects of the gastrocnemius tightness on the joint angle and joint work during walking. METHODS: Twenty-two patients with muscular tightness of gastrocnemius muscle (<12 degrees of ankle dorsiflexion with knee extended) and 22 age- and gender-matched subjects with normal gastrocnemius flexibility (>15 degrees of ankle dorsiflexion with knee extended) participated in this study. The joint angle and work at hip, knee, and ankle joints during the stance phase were analyzed at two preset cadences of 100 steps/min and 140 steps/min. FINDINGS: Significantly greater flexion angles at hip (P=0.025) and knee (P=0.001) were found in the tightness group at the time of maximal ankle dorsiflexion. Significantly less work generation at knee (P=0.034) and greater work absorption at ankle (P=0.024) were detected in the tightness group. INTERPRETATION: The subjects with gastrocnemius tightness revealed a compensatory gait pattern, which included the changes in the joint angles and associated work productions. The potential disturbance of the knee control and strain injuries of plantar flexors might be crucial in the clinical considerations for subjects with gastrocnemius tightness.

Quantitative application of transverse friction massage and its neurological effects on flexor carpi radialis.

The purpose of the study was to determine the effects of transverse friction massage (TFM) on flexor carpi radialis (FCR) motoneuron (MN) pool excitability. Twenty-eight healthy subjects were randomly assigned into massage and control groups. Pre- vs post-TFM H-reflex data were collected. Controls received a rest period instead of massage. Massage dose was standardized by a novel electronic method which recorded the massage rate, momentary pressure and total cumulative pressure (energy). Two-way ANOVA of H/M ratios derived from maximal amplitudes of Hoffman reflexes (Hmax) and motor responses (Mmax) was used to analyze neurological effects and group differences. Analysis of pressure/time curve data showed: mean massage rate was 0.501+/-0.005 Hz; mean duration of massage sessions was 184.6+/-26.4s; mean peak pressure was 4.990+/-1.006 psi. Hmax/Mmax ratios declined from 14.3% to 10.3% for massage (P<0.01) but showed no change for controls (P>0.05). In conclusion a novel quantitative approach to the study of massage has been demonstrated while testing the effects of TFM on FCR MN pool excitability. TFM appears to reduce MN pool excitability. The novel method of quantifying massage permits more rigorous testing of client-centered massage in future research.

Time course analysis of the effects of botulinum toxin type a on elbow spasticity based on biomechanic and electromyographic parameters.

OBJECTIVE: To quantify changes of elbow spasticity over time after botulinum toxin type A (BTX-A) injection in the upper extremity of stroke patients. DESIGN: Before-after trial in which the therapeutic effects were followed up at 2, 6, and 9 weeks after the BTX-A injection (Botox). SETTING: Hospital. PARTICIPANTS: Chronic stroke patients (N=8) with upper-limb spasticity. INTERVENTION: BTX-A was injected in upper-limb muscles, including the biceps brachii. MAIN OUTCOME MEASURES: Treatment effects were quantified as the changes in the velocity and the length dependence of hyperexcitable stretch reflexes. Manual sinusoid stretches of the elbow joint at 4 frequencies (1/3, 1/2, 1, 3/2Hz) over a movement range of 60 degrees were performed on patients by using a portable device. The Modified Ashworth Scale (MAS), biomechanic viscosity, and the reflexive electromyography threshold (RET) of the biceps brachii were used to evaluate the degree of hypertonia. RESULTS: The statistical analyses of the MAS score, biomechanic viscosity, and RET revealed a significant decrease in spasticity after the injection (all P<.05). Moreover, our quantitative parameters (biomechanic viscosity, RET) revealed small changes in spasticity after the BTX-A injection that could not be observed from clinical MAS evaluations. Five of 8 subjects showed a maximal reduction in spasticity (in terms of biomechanic viscosity value) within 6 weeks after the injection, whereas it was notable that all subjects exhibited peak RET values at either 2 or 6 weeks after the injection with variable degrees of relapse of spasticity. CONCLUSIONS: Early relapse of spasticity (within 9 weeks of the injection) can be detected from biomechanic and neurophysiologic assessments in a clinical setup. These quantitative indices provide valuable information for clinicians when making decisions to perform additional rehabilitation interventions or another BTX-A injection in the early stages of treatment.

Development of a quantitative assessment system for correlation analysis of footprint parameters to postural control in children.

It is known that neurological impairments impact postural stability, but few studies have observed the biomechanical influence of foot structure on balance. The aim of this study was to develop an integrated device for investigating the relationship between static balance and the foot structure, derived from a footprint image, under clinical tests of sensory interactions. Quantitative analysis of the footprint image acquired during balanced standing was developed as an indirect measure of the longitudinal arch, an important structural component of the foot. A data pool was collected from 64 children, 32 children from each of two age groups (4-5 years old versus 8-10 years old). Six common footprint parameters derived from the footprint angle or contact area were used to investigate the relationship between footprint parameters and postural stability. Postural balance ability was evaluated by analyzing sway area in posturography under visual or somatosensory confliction conditions. The footprint parameters, derived from the footprint image, inter-correlated well with each other (p < 0.01). The relationships between footprint parameters and sway area were correlated only for younger children under visually deprived (eye close) and cutaneous unreliable (standing on compliant foam) conditions. This implies that the correlations between footprint parameters and sway area are very subtle which can only be observed in unreliable visual and somatosensory conditions of younger children. In addition, younger children with a lower arch height would have a smaller sway area and better posture control which might result from more cutaneous somatosensation or a flexible biomechanical structure in low arch feet during conditioned static standing.

The use of a portable muscle tone measurement device to measure the effects of botulinum toxin type a on elbow flexor spasticity.

OBJECTIVE: To use a portable muscle tone assessment device to measure spasticity after a botulinum toxin type A (BTX-A) injection. DESIGN: Before-after trial. SETTING: Hospital. PARTICIPANTS: Ten chronic stroke patients with upper-limb spasticity. INTERVENTION: BTX-A was injected in the biceps brachii. MAIN OUTCOME MEASURES: The biomechanic parameters, viscous component, and averaged viscosity derived from the acquired reactive resistance and angular displacements, as well as the reflex electromyographic threshold of biceps brachii, were used for spasticity evaluation. RESULTS: A statistically significant decrease in averaged viscosity and a significant increase in reflex electromyographic threshold (P<.05) both indicated reduction in spasticity owing to BTX-A intervention. There was no clear reflex electromyographic activity detected at lower stretch frequencies. CONCLUSIONS: Our portable design allows for the convenient use of the device for quantifying spasticity in clinics. All quantitative measurements suggest that BTX-A decreases spasticity within 2 weeks of injection. Our portable muscle tone measurement device may be useful for the clinical assessment of elbow flexor spasticity.