Faculty Bibliography

BACKGROUND:Older age is associated with higher stride time variability in female and male gait, which may have a neuromuscular origin. We sought to determine how older age and sex affect muscle activation variability during gait, and how these patterns relate to stride time variability. METHODS:Ninety-three adults (51 females; aged 20-82 years) completed six gait trials at their self-selected speed. Cycle-to-cycle variabilities (CCVs) were calculated for stride time, and for amplitude of electromyography (EMG) of the rectus femoris (RF), tibialis anterior (TA), and gastrocnemius lateralis (GL) recorded over different gait phases. Statistical models tested for Age × Sex × Muscle effects and for relationships between EMG CCVs and stride time CCVs. RESULTS:Significant Age and Age × Muscle effects on EMG CCV were observed in several phases of gait (p < .05), where each year of age was associated with 0.11-0.18% higher EMG CCV, generally in the RF. A significant Age × Sex × Muscle effect on EMG CCV at mid-stance (p < .05) indicated that, in females, each year of age was associated with 0.11% lower GL CCV. Significant but low strength correlations (ρ = 0.298-0.351) were found between EMG CCV and stride time CCV. CONCLUSIONS:Associations between older age and higher muscle activation variability were generally sex-independent. A sex-dependency in GL activation variability may contribute to gait instability in aging females. Individual variabilities of muscle activation were not strongly related to stride time variability.

OBJECTIVE:This study aimed to quantitatively investigate the existence of differences in spatiotemporal and kinematic parameters of gait in men and women with Parkinson disease (PD) using computerized 3-dimensional gait analysis. DESIGN:Retrospective cohort study. SETTING:Laboratory of Biomechanics. PARTICIPANTS:Individuals with PD (N=35; 17 female, 18 male) of mean age 70.7 years characterized by mild disability (Hoehn and Yahr ≤2.5) who were tested in On medication state approximately 60 to 90 minutes after intake of the usual morning Levodopa dose. INTERVENTION:Not applicable. MAIN OUTCOME MEASURES:Spatiotemporal parameters of gait (speed, stride length, cadence, step width, duration of stance, swing, double support phases) and kinematics of hip, knee, and ankle joints in the sagittal plane. RESULTS:Men and women exhibit similar spatiotemporal parameters, except for step width (wider in men). In contrast, relevant differences were found in terms of ankle kinematics. In particular, women presented increased ankle dorsiflexion through all the stance phase and mid to late swing phase, and reduced plantarflexion at the stance-swing phase transition. CONCLUSIONS:Gait patterns of men and women with PD with mild disability are similar in terms of spatiotemporal parameters but characterized by marked differences regarding the ankle kinematics on the sagittal plane. The findings of the present study support the concept that investigations seeking to clarify the complex pathophysiology of PD-related gait disturbances should consider the role played by an individual's sex, thereby achieving more effective designing of physical and rehabilitative treatments.

OBJECTIVES/OBJECTIVE:To assess the effect of competitive level on dynamic postural stability in young elite and sub-elite soccer players. DESIGN/METHODS:Cross-sectional study. SETTING/METHODS:Laboratory. PARTICIPANTS/METHODS:Fifty-four male soccer players of Under 16 and Under 17 categories (mean age 15.9 ± 0.6), divided into two groups who regularly compete at national (n = 28) and regional (n = 26) levels. MAIN OUTCOME MEASURES/METHODS:Dynamic Postural Stability Index (DPSI) and vertical Time to Stabilization (vTTS) for a forward-jump landing. Static postural sway was calculated on the basis of center-of-pressure trajectories for a 20 s one-legged stance. RESULTS:Players at national level exhibit better dynamic postural control than those at regional level, as indicated by the significantly lower DPSI (0.327 vs. 0.373, p < 0.001) and vTTS (0.887 vs. 1.158 s, p = 0.003). In contrast, no differences between groups were found in any of the postural sway parameters for the static test. CONCLUSIONS:Young soccer players at national level are characterized by better balance performance in terms of faster and more efficient stabilization after a forward jump, while one-leg static standing tests appear not challenging enough to reveal differences in balance abilities associated with the combination of superior technical and physical features.

BACKGROUND:In children with spastic cerebral palsy (CP), the treatment of equinus foot with Achilles tendon lengthening (ATL) surgery is associated with high incidence of overcorrection, which may result in crouch gait. AIM/OBJECTIVE:We aimed to assess if gait pattern in preoperative time could be a predictor of the surgery outcome. DESIGN/METHODS:Cross-sectional retrospective study. SETTING/METHODS:Movement Analysis Lab of IRCCS San Raffaele Pisana Hospital in Rome (Italy). POPULATION/METHODS:Eighteen children (mean age 9.6±4.7 years) with spastic diplegia CP who underwent bilateral ATL surgery to correct equinus foot were involved. METHODS:Participants underwent 3D gait analysis before and approximately 12 months after surgery. Primary measures were spatiotemporal, kinematic (summarized by Gait Variable Scores, GVSs) and kinetic parameters. The gait patterns for each leg was defined from kinematic data, using a quantitative classification: plantar flexor knee extension (PFKE) index. The CP group was split into true equinus and jump gait. RESULTS:The equinus foot was successfully corrected as demonstrated by the improvement of GVS ankle dorsi-plantarflexion. However, there was a high rate of overcorrection in the true equinus, characterized by increases in knee flexion-extension GVS (8.7° pre vs. 16.7° post P<0.05) and knee flexion angle at initial contact (5.2° vs. 20.6° P<0.05) and by a decrease in the maximum ankle power generated at push-off (1.49 vs. 0.83 W/kg P<0.05). CONCLUSIONS:Assessment of motor phenotype in preoperative time are good predictors of the results of ATL surgery. In children with true equinus gait, the increase of knee flexion subsequent to ATL is an early indicator that this technique will lead to crouch gait. These results show the influence of true equinus and jump gait patterns on the outcomes of the ATL. CLINICAL REHABILITATION IMPACT/CONCLUSIONS:Therefore, we propose that this approach could have clinical value to evaluate and prescribe rehabilitation in children with CP disease, proposing different solutions depending on motor phenotype.

Background: Walking impairments are one of the most impactful consequences of multiple sclerosis (MS). Recently, physical rehabilitation research has focused on developing synergistic protocols to enhance clinical benefit. Recent studies have shown that transcranial direct current stimulation (tDCS) and aerobic physical activity (PA) have converging activation pathways and when completed simultaneously, they may promote cortical neuroplasticity.
Objective(s): To harness cortical plasticity to improve gait for individuals with MS.
Aim(s): To investigate the effects of multiple sessions of PA with simultaneously administered tDCS on walking abilities.
Method(s): MS participants (EDSS: 1-6.5, Relapsing-Remitting or Secondary-Progressive subtype) with clinically significant gait deviations were recruited for a randomized controlled trial of 10 sessions of either active or sham tDCS paired with unloaded cycling for 20 minutes. Stimulation was administered over the primary motor cortex (2.5 mA-2.0 mA; anode over C3/cathode over FP2). Walking speed was assessed quantitatively by using a single inertial sensor placed on the lower back and perceived walking abilities were evaluated using the 12-Item MS Walking Scale (MSWS-12), a self-report questionnaire. Measurements were collected at baseline, the end of tDCS intervention, and 4-weeks post-intervention. Two-way repeated measures-ANOVA (Time, Treatment) was performed to investigate differences between active and sham conditions.
Result(s): Thirty-two participants were enrolled in the study, 22 underwent active treatment. No demographic differences were detected between active and sham groups (active:EDSS 4.3+/-1.2, age 55.5+/-10.3; sham:EDSS 4.5+/-1.5, age 49.7+/-13.9). Statistical analysis showed significant Treatment by Time interactions for gait speed and MSWS-12 score. Post-hoc analysis revealed that gait speed increased significantly after active treatment (Baseline vs. End Treatment, 0.98 vs. 1.16 m/s, p< 0.001; Baseline vs. Follow-up, 0.98 vs. 1.20 m/s, p< 0.001). Active group further reported significant improvement in self-report measure (Baseline vs. End Treatment, 58.04 vs. 49.73, p< 0.05). No significant difference was detected after sham stimulation.
Conclusion(s): Our results indicate that multiple sessions of tDCS administered simultaneously with PA induce cumulative and selfreport improvement in walking and benefits persisted until 4-week post-intervention

BACKGROUND:Progressive cerebellar ataxia is a neurodegenerative disorder without effective treatment options that seriously hinders quality of life. Previously, transcranial direct current stimulation (tDCS) has been demonstrated to benefit cerebellar functions (including improved motor control, learning and emotional processing) in healthy individuals and patients with neurological disorders. While tDCS is an emerging therapy, multiple daily sessions are needed for optimal clinical benefit. This case study tests the symptomatic benefit of remotely supervised tDCS (RS-tDCS) for a patient with cerebellar ataxia. METHODS:We report a case of a 71-year-old female patient with progressive cerebellar ataxia, who presented with unsteady gait and balance impairment, treated with tDCS. tDCS was administered using our RS-tDCS protocol and was completed daily in the patient's home (Monday - Friday) with the help of a trained study technician. tDCS was paired with 20 min of simultaneous cognitive training, followed by 20 min of physical exercises directed by a physical therapist. Stimulation consisted of 20 min of 2.5 mA direct current targeting the cerebellum via an anodal electrode and a cathodal electrode placed over the right shoulder. The patient completed baseline and treatment end visits with neurological, cognitive, and motor (Lafayette Grooved Pegboard Test, 25 ft walk test and Timed Up and Go Test) assessments. RESULTS:The patient successfully completed sixty tDCS sessions, 59 of which were administered remotely at the patient's home with the use of real time supervision as enabled by video conferencing. Mild improvement was observed in the patient's gait with a 7% improvement in walking speed, which she completed without a walking-aid at treatment end, which was in stark contrast to her baseline assessment. Improvements were also achieved in manual dexterity, with an increase in pegboard scores bilaterally compared to baseline. CONCLUSIONS:Results from this case report suggest that consecutively administered tDCS treatments paired with cognitive and physical exercise hold promise for improving balance, gait, and manual dexterity in patients with progressive ataxia. Remotely supervised tDCS provides home access to enable the administration over an extended period. Further controlled study in a large group of those with cerebellar ataxia is needed to replicate these findings. TRIAL REGISTRATION/BACKGROUND:ClinicalTrials.gov Identifier: NCT03049969 . Registered 10 February 2017- Retrospectively registered.