Wei-Li Hsu

Image changes of paraspinal muscles and clinical correlations in patients with unilateral lumbar spinal stenosis

Study designThis is a retrospective study.PurposeTo compare the morphometric parameters of the psoas major and lumbar multifidus muscles in lumbar spinal stenosis (LSS) patients exhibiting different functional performance.Summary of background dataLSS refers to symptoms related to size reduction of the lumbar spinal canal; however, the degree of stenosis is poorly related to symptom severity and functional impairments. Morphometric changes in the paraspinal muscles have been correlated with chronic lower back pain in previous studies. However, correlations between the functional performance of LSS patients and the morphometric changes in paraspinal muscles have seldom been reported.MethodsSixty-six LSS patients without mechanical back pain or segmental instability were enrolled in the study. A review of their medical records and MRI images was performed. Morphometric parameters, including the fatty infiltration (FI) of the lumbar multifidus muscle as well as the relative cross-sectional area (RCSA) of the psoas major and lumbar multifidus muscles, were measured. Subjects were divided into high and low functional performance groups according to their Japanese Orthopedic Association (JOA) scores.ResultsThe male LSS patients exhibited a larger psoas RCSA than the female patients, whereas the older patients exhibited a smaller psoas RCSA and higher multifidus FI than the younger patients. LSS patients in the high functional performance group exhibited a significantly larger psoas RCSA and lower multifidus FI.ConclusionThe psoas RCSA and multifidus FI can be used as predictive factors for functional performance in LSS patients.

Balance control in elderly people with osteoporosis

Osteoporosis is a prevalent health concern among older adults and is associated with an increased risk of falls that incur fracture, injury, or mortality. Identifying the risk factors of falls within this population is essential for the development of effective regimes for fall prevention. Studies have shown that muscle quality and good posture alignments are critical for balance control in elderly individuals. People with osteoporosis often have muscle weakness and increased spine kyphosis leading to vertebral fractures and poor balance control, or even falls. Therefore, improving muscle quality, strengthening weak muscles, and correcting postural alignment are essential elements for the prevention of falls and fractures in older adults with osteoporosis. This review reports the necessary information regarding the critical factors of balance control in older adults with osteoporosis, as well as testing the clinical innovations of exercise training to improve the long-term prognosis of osteoporosis in this vulnerable population.

Altered Co-contraction of Cervical Muscles in Young Adults with Chronic Neck Pain during Voluntary Neck Motions.

[Purpose] Muscle co-contraction is important in stabilizing the spine. The aim of this study was to compare cervical muscle co-contraction in adults with and without chronic neck pain during voluntary movements. [Subjects and Methods] Surface electromyography of three paired cervical muscles was measured in fifteen young healthy subjects and fifteen patients with chronic neck pain. The subjects performed voluntary neck movements in the sagittal and coronal plane at slow speed. The co-contraction ratio was defined as the normalized integration of the antagonistic electromyography activities divided by that of the total muscle activities. [Results] The results showed that the co-contraction ratio of patients was greater during flexion movement, lesser during extension movement, slightly greater during right lateral bending, and slightly lesser during left lateral bending compared with in the controls. [Conclusion] The results suggested that neck pain patients exhibit greater antagonistic muscle activity during flexion and dominate-side bending movements to augment spinal stability, while neuromuscular control provides relatively less protection in the opposite movements. This study helps to specify the changes of the stiffness of the cervical spine in neck pain patients and provides a useful tool and references for clinical assessment of neck disorders.

Use of motor abundance in old adults in the regulation of a narrow-based stance.

AbstractPurpose The ability to maintain stable balance while standing decreases with age. The body must coordinate multiple joints using “freeze” or “free” strategy, or a combination of both to ensure balance stability. The purpose of this study was to examine age-related changes in the use of motor abundance during upright stance on a narrow base without visual input.MethodsUncontrolled manifold (UCM) analysis was used to decompose the movement variability of joints into goal-equivalent variability (GEV) and non-goal-equivalent variability (NGEV). The ratio between GEV and NGEV (UCMratio) quantifies the joint coordination related to postural stability, and a high UCMratio value indicates flexible control of joints. To perform balance tests, participants in this study (healthy young and old adults, 20 each) were asked to stand on a flat platform and on narrow wooden blocks with their eyes open and then eyes closed.ResultsIn upright balance tests, both old and young adults maintained postural stability. GEV was greater than NGEV across all participants and conditions. However, GEV was higher in the young adults than in the old adults, whereas NGEV was higher in the old adults than in the young adults. Therefore, the old adults exhibited a lower UCMratio than the young adults.ConclusionThe old adults were unable to exploit motor abundance and used a less flexible multi-joint coordination pattern to achieve stable balance. The UCMratio value reflects the quality of postural control and can be used for assessing joint coordination in balance disorders.

Motion analysis of axial rotation and gait stability during turning in people with Parkinson's disease

BACKGROUND Axial rigidity and postural instability in people with Parkinsons disease (PD) may contribute to turning difficulty. This study examined the rotation of axial segments and gait instability during turning in people with PD. METHODS Thirteen PD and twelve age-matched healthy adults were recruited. Participants performed the timed Up-and-Go test and were recorded by a 3D motion capture system. Axial rotation was evaluated by the rotation onset of the head, thorax and pelvis. Gait stability was evaluated by the center of mass and center of pressure inclination angle. Turning performance was evaluated by turning time and turning steps. RESULTS During turning, PD adults rotated the head, thorax and pelvis simultaneously, whereas healthy adults rotated in a cranial to caudal sequence. Further, PD adults had a smaller sagittal inclination angle (p<0.001) but larger frontal inclination angle (p=0.006) than healthy adults. PD adults also turned slower (p=0.002) with a greater number of steps (p<0.001) than healthy adults. Last, PD adults showed a significant correlation between the sagittal inclination angle and turning steps (Spearmans ρ=-0.63), while healthy adults showed a significant correlation between frontal inclination angle and turning steps (Spearmans ρ=-0.67). CONCLUSION This study demonstrated the axial rigidity in PD adults during turning may reduce forward progression and increase lateral instability. The reduced progression is associated with extra turning steps and the increased lateral instability may result in great fall risk.

Changes of postural control and muscle activation pattern in response to external perturbations after neck flexor fatigue in young subjects with and without chronic neck pain

PURPOSE Previous studies have identified sensorimotor disturbances and greater fatigability of neck muscles in patients with neck pain. The purpose of this study was to investigate the effect of neck pain and neck flexor fatigue on standing balance following postural perturbations. METHODS Twenty patients with chronic neck pain (CNP) (24.7±3.6 year-old) and 20 age-matched asymptomatic subjects (22.1±2.2 year-old) were recruited. Subjects stood barefoot on a force plate and experienced backward perturbations before and after neck flexor fatigue. Center of pressure, electromyography of cervical and lumbar muscles, and head/trunk accelerations were recorded. Two-way ANOVA (pain×fatigue) was used for statistical analysis. RESULTS CNP group showed larger body sway during quiet standing but not during perturbed standing compared with asymptomatic adults. In both groups, neck flexor fatigue resulted in greater body sway during the quiet standing but smaller body sway during perturbed standing, increased neck muscle activations and decreased lumbar muscle activations, as well as increased time to maximal head acceleration. CONCLUSIONS Disturbed balance control was observed in CNP patients during the quiet standing. However, a rigid strategy was used to minimize the postural sway and to protect the head against backward perturbations in both CNP and asymptomatic young adults after neck flexor fatigue. The results facilitate the understanding of how the subjects with chronic neck pain and with neck muscle fatigue deal with the challenging condition. Further studies are needed to verify if such phenomenon could be changed after the intervention of specific flexor muscle retraining and balance control exercises.

Effects of Therapeutic Physical Agents on Achilles Tendon Microcirculation

STUDY DESIGN Controlled laboratory study. OBJECTIVES To measure Achilles tendon microcirculation (total hemoglobin [THb] and oxygen saturation [StO2]) before and after the application of a physical agent in asymptomatic participants, and to compare differences between application location and physical agent dosage. BACKGROUND Tendon microcirculation can be altered by superficial heating or cryotherapy. METHODS Fifty-one healthy adults (median age, 22 years; range, 20-34 years) were recruited and randomly assigned into 1 of 4 groups. Participants in each group received an intervention consisting of 1 of the following 4 physical agents: ultrasound (n = 12), interferential current (n = 14), low-level laser (n = 11), or vibration massage (n = 14). In each group, the selected intervention was applied at 2 different doses (ultrasound, 0.8 or 1.2 W/cm(2); laser, 5.4 or 18 J) or target locations (vibration and electrostimulation, calf muscle or Achilles tendon). For each participant, each dose or target location was randomly applied to 1 randomly selected lower leg (each leg receiving only 1 of the 2 options). RESULTS The StO2 values significantly increased after ultrasound at both doses (P<.008), and the THb value significantly increased for the higher dose only (P<.008). Both THb and StO2 values also significantly increased in response to vibration massage targeting the Achilles tendon (P<.008), and these values were greater than those resulting from the vibration massage applied to the calf muscle (P = .003 and .002, respectively). No significant THb and StO2 differences were found after the application of interferential current or low-level laser. CONCLUSION Tendon microcirculation increases after ultrasound and vibration massage intervention concentrated on the Achilles tendon. These modalities may be considered for the purpose of temporarily increasing microcirculation in the tendon.

Responsiveness of the Chinese versions of the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire and Neck Disability Index in postoperative patients with cervical spondylotic myelopathy.

Study Design. Prospective cohort study. Objective. To evaluate the postoperative responsiveness of the Chinese versions of the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) and the Neck Disability Index (NDI) in a cohort of patients with cervical spondylotic myelopathy. Summary of Background Data. We have recently completed the translation and cross-cultural adaptation of a Chinese version of JOACMEQ. However, the postoperative responsiveness of the Chinese JOACMEQ and how it compares with the more commonly used NDI remain undetermined. Methods. Forty-five patients with cervical spondylotic myelopathy undergoing surgical decompression were recruited. All patients completed the Chinese JOACMEQ and the NDI preoperatively and again at 3-month follow-up together with an 11-point Global Rating of Change scale. Patients were dichotomized either as “Improved” or “Stable” on the basis of Global Rating of Change. Paired t test, standardized effect sizes, and Guyatt responsiveness index were used to determine internal responsiveness. External responsiveness was evaluated by the area under the receiver operating characteristic curve and the minimal clinically important change was determined as the optimal cutoff point for patient discrimination anchor-based on Global Rating of Change classification. Results. Bladder function and quality of life (QOL) domains (P < 0.03) of the JOACMEQ and the NDI (P = 0.004) reached statistically significant difference with the paired t test. After the dichotomization, the standardized effect size was strong for the QOL domain in the improved group (0.85) and the Cervical spine function (0.97) in the stable group, respectively. Based on the Guyatt responsiveness index, strong responsiveness was found for the Bladder function (0.88) and QOL (0.76) domains of the JOACMEQ and moderate responsiveness (0.55) for the NDI. The Bladder function (area = 0.82; minimal clinically important change = 6) and QOL (0.83; minimal clinically important change = 8.5) also produced largest area under the receiver operating characteristic curve. Conclusion. Bladder function and QOL domains of the JOACMEQ seem to demonstrate the strongest postoperative responsiveness and thus may be more appropriate than NDI when attempting to determine treatment efficacy in cervical spondylotic myelopathy. Level of Evidence: 3

Trunk Control Ability after Minimally Invasive Lumbar Fusion Surgery during the Early Postoperative Phase.

[Purpose] Lumbar fusion has been used for spinal disorders when conservative treatment fails. The minimally invasive approach causes minimal damage to the back muscles and shortens the postoperative recovery time. However, evidence regarding functional recovery in patients after minimally invasive lumbar spinal fusion is limited. The purpose of this study was to investigate how trunk control ability is affected after minimally invasive lumbar fusion surgery during the early postoperative phase. [Subjects and Methods] Sixteen patients and 16 age- and sex-matched healthy participants were recruited. Participants were asked to perform a maximum forward reaching task and were evaluated 1 day before and again 1 month after the lumbar fusion surgery. Center of pressure (COP) displacement, back muscle strength, and scores for the Visual Analog Scale, and Chinese version of the modified Oswestry Disability Index (ODI) were recorded. [Results] The healthy control group exhibited more favorable outcomes than the patient group both before and after surgery in back strength, reaching distance, reaching velocity, and COP displacement. The patient group improved significantly after surgery in all clinical outcome measurements. However, reaching distance decreased, and the reaching velocity as well as COP displacement did not differ before and after surgery. [Conclusion] The LBP patients with lumbar fusion surgery showed improvement in pain intensity 1 month after surgery but no improvement in trunk control during forward reaching. The results provide evidence that the back muscle strength was not fully recovered in patients 1 month after surgery and limited their ability to move their trunk forward.

Immediate Effects of Clock-Turn Strategy on the Pattern and Performance of Narrow Turning in Persons With Parkinson Disease.

Background and Purpose: Turning difficulty is common in people with Parkinson disease (PD). The clock-turn strategy is a cognitive movement strategy to improve turning performance in people with PD despite its effects are unverified. Therefore, this study aimed to investigate the effects of the clock-turn strategy on the pattern of turning steps, turning performance, and freezing of gait during a narrow turning, and how these effects were influenced by concurrent performance of a cognitive task (dual task). Methods: Twenty-five people with PD were randomly assigned to the clock-turn or usual-turn group. Participants performed the Timed Up and Go test with and without concurrent cognitive task during the medication OFF period. The clock-turn group performed the Timed Up and Go test using the clock-turn strategy, whereas participants in the usual-turn group performed in their usual manner. Measurements were taken during the 180° turn of the Timed Up and Go test. The pattern of turning steps was evaluated by step time variability and step time asymmetry. Turning performance was evaluated by turning time and number of turning steps. The number and duration of freezing of gait were calculated by video review. Results: The clock-turn group had lower step time variability and step time asymmetry than the usual-turn group. Furthermore, the clock-turn group turned faster with fewer freezing of gait episodes than the usual-turn group. Dual task increased the step time variability and step time asymmetry in both groups but did not affect turning performance and freezing severity. Discussion and Conclusions: The clock-turn strategy reduces turning time and freezing of gait during turning, probably by lowering step time variability and asymmetry. Dual task compromises the effects of the clock-turn strategy, suggesting a competition for attentional resources. Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A141).