Citlali López-Ortiz

Bilateral limb phase relationship and its potential to alter muscle activity phasing during locomotion.

It is well established that the sensorimotor state of one limb can influence another limb and therefore bilateral somatosensory inputs make an important contribution to interlimb coordination patterns. However, the relative contribution of interlimb pathways for modifying muscle activation patterns in terms of phasing is less clear. Here we studied adaptation of muscle activity phasing to the relative angular positions of limbs using a split-crank ergometer, where the cranks could be decoupled to allow different spatial angular position relationships. Twenty neurologically healthy individuals performed the specified pedaling tasks at different relative angular positions while surface electromyographic (EMG) signals were recorded bilaterally from eight lower extremity muscles. During each experiment, the relative angular crank positions were altered by increasing or decreasing their difference by randomly ordered increments of 30 degrees over the complete cycle [0 degrees (in phase pedaling); 30, 60, 90, 120, 150, and 180 degrees (standard pedaling); and 210, 240, 270, 300, and 330 degrees out of phase pedaling]. We found that manipulating the relative angular positions of limbs in a pedaling task caused muscle activity phasing changes that were either delayed or advanced, dependent on the relative spatial position of the two cranks and this relationship is well-explained by a sine curve. Further, we observed that the magnitude of phasing changes in biarticular muscles (like rectus femoris) was significantly greater than those of uniarticular muscles (like vastus medialis). These results are important because they provide new evidence that muscle phasing can be systematically influenced by interlimb pathways.

Pilot study of a targeted dance class for physical rehabilitation in children with cerebral palsy

Introduction: This pilot study evaluates the effects of a targeted dance class utilizing classical ballet principles for rehabilitation of children with cerebral palsy on balance and upper extremity control. Methods: Twelve children with cerebral palsy (ages 7–15 years) with Gross Motor Function Classification scores II–IV participated in this study and were assigned to either a control group or targeted dance class group. Targeted dance class group participated in 1-h classes three times per week in a 4-week period. The Pediatric Balance Scale and the Quality of Upper Extremity Skills Test were administered before, after, and 1 month after the targeted dance class. Results: Improvements in the Pediatric Balance Scale were present in the targeted dance class group in before versus after and before versus 1 month follow-up comparisons (p-value = 0.0088 and p-value = 0.019, respectively). The Pediatric Balance Scale changes were not significant in the control group. The Quality of Upper Extremity Skills Test did not reach statistical differences in either group. Conclusion: Classical ballet as an art form involves physical training, musical accompaniment, social interactions, and emotional expression that could serve as adjunct to traditional physical therapy. This pilot study demonstrated improvements in balance control. A larger study with a more homogeneous sample is warranted.

Motor Learning in Children with Cerebral Palsy with Feedback of Principal Component Space of Reduced Dimension

Cerebral palsy (CP) is the most common developmental motor disorder in children characterized by atypical or abnormal muscle tone, weakness, and reduced selective motor control. This results in abnormal movements and postures. Augmented therapeutic modalities to train selective motor control are needed in CP rehabilitation. We investigated motor learning in children with CP (n=9, ages 8-12, GMFCS =I,II) by providing feedback in a virtual reality (VR) environment of reduced dimensions consisting only of the first two principal components (PCs) of the space of target postures from a group of typically developing children (n=8, ages 8-12). After six training sessions we observed the following changes in the children’s motor control: a) increased variance in the first principal component; b) reduced variance in the non- relevant principal components; and c) increased the number of target matches. These results suggest that feedback of reduced dimensions by remapping space into its main principal components in a game like environment may increase selective motor control in children with CP.

Targeted ballet program mitigates ataxia and improves balance in females with mild-to-moderate multiple sclerosis

Background Multiple sclerosis (MS) is a disease of the central nervous system that causes ataxia and deficits in balance. Exercise-based therapies have been identified as integral to the recovery of motor function in MS, but few studies have investigated non-traditional movement interventions. We examined a targeted ballet program (TBP) designed to mitigate ataxia and improve balance in females with mild-to-moderate relapsing-remitting MS. Methods and findings Twelve females with mild-to-moderate disability due to MS were assessed for study eligibility for the study. Ten participants met the inclusion criteria. Two were lost to unrelated health complications. Eight participants completed the TBP. The TBP met twice a week for 60 minutes for 16 weeks. Assessments included (a) the International Cooperative Ataxia Rating Scale (ICARS), (b) the Mini-Balance Evaluations Systems Test (Mini-BESTest), (c) smoothness of movement during a five-meter walk, and (d) balance in a step to stand task before and after the TBP. There were no TBP-related adverse events. Single-tailed paired samples t-tests and Wilcoxon tests were conducted. Improvements were observed in ICARS (p = 7.11E-05), Mini-BESTest (p = 0.001), smoothness of movement in the left (p = 0.027) and right (p = 0.028) sides of the body, and balance in a step-to-stand task in the back (p = 0.025) direction. Results yielded 42% and 58% improvements in the mean Mini-BESTest and ICARS scores, respectively. Conclusions This study adds to current research by providing support for a TBP intervention targeting ataxia and balance in MS. The TBP was well tolerated, improved balance, and mitigated ataxia. Clinical improvements were larger than those of previous studies on physical rehabilitation in MS with similar outcome measures. Trial registration ISRCTN ISRCTN67916624.

Skeletal Muscle Adaptations and Passive Muscle Stiffness in Cerebral Palsy: A Literature Review and Conceptual Model

This literature review focuses on the primary morphological and structural characteristics, and mechanical properties identified in muscles affected by spastic cerebral palsy (CP). CP is a non-progressive neurological disorder caused by brain damage and is commonly diagnosed at birth. Although the brain damage is not progressive, subsequent neuro-physiological developmental adaptations may initiate changes in muscle structure, function, and composition, causing abnormal muscle activity and coordination. The symptoms of CP vary among patients. However, muscle spasticity is commonly present and is one of the most debilitating effects of CP. Here, we present the current knowledge regarding the mechanical properties of skeletal tissue affected by spastic CP. An increase in sarcomere length, collagen content, and fascicle diameter, and a reduction in the number of satellite cells within spastic CP muscle were consistent findings in the literature. Studies differed, however, in changes in fascicle lengths and fiber diameters. We also present a conceptual mechanical model of fascicle force transmission that incorporates mechanisms that impact both serial and lateral force production, highlighting the connections between the macro and micro structures of muscle to assist in deducing specific mechanisms for property changes and reduced force production.

Dance and rehabilitation in cerebral palsy: a systematic search and review

To conduct a review of research literature on the use of dance and movement with music (rhythmic auditory stimulation [RAS]) in the neurorehabilitation of children and adults with cerebral palsy (CP).

Targeted dance program for improved mobility in multiple sclerosis

Multiple sclerosis (MS) is a disease of the central nervous system with impaired communication between the brain and the body. Walking impairment is prevalent in MS. There is no documented evidence for improving walking agility or smoothness of movements in exercise interventions for those with MS. We report the results of a classical ballet based targeted dance program on clinical measures of balance, posture, and ataxia as well as a quantitative measure of smoothness of gait. The results demonstrate statistically significant improvements in all measures.

Sound and Rehabilitation Robotics for Pediatric Cerebral Palsy

Robots for pediatric rehabilitation are expected to have sensory-motor components and mixed media elements to enhance rehabilitation outcomes and make robotic therapy amenable to children. We have investigated the effect of sound in voluntary movement trajectory formation of children with cerebral palsy. The results indicate that including a musical melody during the execution of movement may be beneficial in robotic applications designed for the treatment of children with spastic cerebral palsy.