Outcomes of active cervical therapeutic exercise on dynamic intervertebral foramen changes in neck pain patients with disc herniation.

BACKGROUND: To better understand biomechanical factors that affect intervertebral alignment throughout active therapeutic exercise, it is necessary to determine spinal kinematics when subjects perform spinal exercises. This study aims to investigate the outcomes of active cervical therapeutic exercise on intervertebral foramen changes in neck pain patients with disc herniation. METHODS: Thirty diagnosed C4/5 and/or C5/6 disc-herniated patients receiving an 8-week cervical therapeutic exercise program were followed up with videofluoroscopic images. The dynamic changes in the foramen were computed at different timepoints, including the neutral position, end-range positions in cervical flexion-extension, protrusion-retraction, and lateral flexion movements. RESULTS: The results showed that the active cervical flexion, retraction, and lateral flexion away from the affected side movements increased the area of the patients' intervertebral foramen; while the active extension, protrusion, and lateral flexion toward the affected side reduced the areas of intervertebral foramen before treatment. After the treatment, the active cervical flexion significantly increased the C2/3, C3/4, and C6/7 foramen area by 5.02-8.67% (p = 0.001 ~ 0.029), and the extension exercise significantly reduced the C2/3 and C4/5 area by 5.12-9.18% (p = 0.001 ~ 0.006) compared to the baseline. Active retraction movement significantly increased the foramen area from C2/3 to C6/7 by 3.82-8.66% (p = 0.002 ~ 0.036 with exception of C5/6). Active lateral flexion away from the affected side significantly increased the foramen by 3.71-6.78% (p = 0.007 ~ 0.046 with exception of C6/7). CONCLUSIONS: The 8-week therapeutic exercises including repeated cervical retraction, extension, and lateral flexion movements to the lesion led to significant changes and improvements in intervertebral foramen areas of the patients with disc herniation. TRIAL REGISTRATION: ISRCTN61539024.

The shift of segmental contribution ratio in patients with herniated disc during cervical lateral bending.

BACKGROUND: Abnormal intervertebral movements of spine have been reported to be associated with trauma and pathological conditions. The importance of objective spinal motion imaging assessment in the frontal plane was frequently underestimated. The clinical evaluation of the segmental motion contribution could be useful for detecting the motion pattern of individual vertebrae. Therefore the purpose of this study was to investigate the shift of segmental contribution ratio in patients with herniated disc during cervical lateral bending to provide additional insights to cervical biomechanics. METHODS: A total of 92 subjects (46 healthy adult subjects and 46 disc-herniated patients) were enrolled in this case-control study. The motion images during cervical lateral bending movements were digitized using a precise image protocol to analyze the intervertebral motion and contribution. RESULTS: Our results showed that the intervertebral angulation during cervical lateral bending for the C2/3 to C6/7 segments were 7.66°±2.37°, 8.37°±2.11°, 8.91°±3.22°, 7.19°±2.29°, 6.31°±2.11°, respectively for the healthy subjects. For the patients with herniated disc, the intervertebral angulation for the C2/3 to C6/7 segments were 6.87°±1.67°, 7.83°±1.79°, 7.73°±2.71°, 5.13°±2.05°, 4.80°±1.93°, respectively. There were significant angulation and translational differences between healthy subjects and the patients with herniated disc in the C5/6 and C6/7 segments (P=0.001-0.029). The segmental contributions of the individual vertebral segments were further analyzed. There was a significant increase in segmental contribution ratio of C3/4 (P=0.048), while a significant decrease in contribution ratio of C5/6 (P=0.037) was observed in the patients with herniated disc. Our results indicated that the segmental contribution shifted toward the middle cervical spine in the patients with herniated disc. CONCLUSIONS: The segmental contributions of cervical spine during lateral bending movement were first described based on the validated radiographic protocol. The detection of the shift of segmental contribution ratio could be helpful for the diagnosis the motion abnormality resulted from the disc or, facet pathologies, and arthritic changes of cervical spine.

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.

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.

Effects of Different Assistive Seats on Ability of Elderly in Sit-To-Stand and Back-To-Sit Movements.

The ability to perform sit-to-stand (STS) and back-to-sit (BTS) movements is important for the elderly to live independently and maintain a reasonable quality of life. Accordingly, this study investigated the STS and BTS motions of 28 healthy older adults (16 male and 12 female) under three different seat conditions, namely nonassisted, self-designed lifting seat, and UpLift seat. The biomechanical data were acquired using a three-dimensional (3D) motion analysis system and force plates, and were examined by one-way repeated-measures ANOVA to investigate the effects of the different seat conditions on the joint angle, joint moments, and movement duration time (α = 0.05). No significant difference was observed in the STS duration among the three test conditions. However, the BTS duration was significantly increased in the UpLift seat condition. Moreover, the peak flexion angle of the hip during STS motion was also significantly higher in the UpLift condition. For both motions (STS and BTS), the lifting seats significantly decreased the knee and hip joint moments, but significantly increased the ankle joint moment. Moreover, compared to the nonassistive seat, both assistive lifting seats required a greater ankle joint strength to complete the STS and BTS motions.

Assessing the mobility of the mandibular condyle by sonography.

PURPOSE: Traditionally, the measurement of the maximal mouth opening was regarded as the mobility of the temporomandibular joint. The information, however, was not reliable. Sonography was often used to diagnose disc displacement in the temporomandibular joint and its validity was well established. The tool was also appropriate for measuring the outcome of temporomandibular disorders management. Therefore, the purpose of the study was to examine completely the reliability and error for evaluating the mobility of the mandibular condyle by sonography. In addition, the existing methods were modified to improve the repeatability. PATIENTS AND METHODS: The reliability examinations included between-image and within-image explorations to represent the reliabilities of the image capturing and the mobility measuring, respectively. Sixty-two subjects were recruited to receive ultrasonic examination for condylar mobility. The images of the condyle in mouth closing and opening were captured and the horizontal displacement of the condyles was measured as the anterior translation of the condyle. To confirm that the probe did not move during mouth opening, a marker was placed between the skin and the ultrasonic probe as the landmark. RESULTS: The results demonstrated that the intrarater and interrater reliabilities in the within-image test were 0.986 and 0.970 and the reliabilities in the between-image test were 0.904 and 0.857, respectively. The standard errors of measurement in the within-image and between-image tests were 0.04 cm and 0.09 cm, respectively. CONCLUSION: Sonography is a reliable tool to assess condylar mobility and can be used to measure the treatment outcome for temporomandibular disorders.

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.

Effect of task constraint on reaching performance in children with spastic diplegic cerebral palsy.

The purposes of the study were to examine the effect of task constraint on the reaching performance in children with spastic cerebral palsy (CP) and to examine the correlations between the reaching performance and postural control. Eight children with CP and 16 typically developing (TD) children participated in the study. They performed a reach-and-return task with a seated posture on a stool. The target for reaching was set at a 120% arm-length distance in three directions (anterior, medial, and lateral). Reaching speed was modulated with a metronome at a rate of 46 beats/min. A motion analysis system recorded the kinematic data of reaching at a sampling rate of 150 Hz. Postural control was assessed with a pediatric reaching test. Movement time (MT), straightness ratio (SR), hand peak velocity (PV), and movement unit (MU) of reaching were compared between groups and among task conditions with repeated measure ANOVAs. Pearson's product-moment correlation coefficients were used to examine the correlations between reaching and postural control. Children with CP presented longer MT, larger SR and more MU than did TD children. Further, the children with CP showed larger SR while reaching medially and laterally than anteriorly. But TD children were not affected by these task constraints. Moderate correlations between postural control ability and SR and MU were noted. In conclusion, the children with CP showed a slower, more skewed, less efficient and less coordinated pattern of reaching than the TD children. Reaching laterally and medially seemed to impair the reaching performance (more skewed and less efficient) of the children with CP, but not of the TD children. Reaching laterally and medially may involve trunk rotation which produces more postural challenges than reaching anteriorly. This finding may explain the difference in the effect of task constraint on hand reaching performance between the two groups of children. Moreover, the better the postural control ability, the straighter, and more efficient and coordinated reaching performance the children showed.

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.

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.