Marcus Fraga Vieira

Background: Hippotherapy is a therapeutic intervention that uses the horse as a biomechanical and sensorimotor agent to promote rehabilitation in individuals with physical and neurological disabilities. Depending on patient needs, riding may be performed with a single rider or with double riding, in which a therapist accompanies the practitioner on the horse. However, the effects of these riding configurations on equine trunk muscle activity remain poorly understood, despite their relevance for both horse welfare and the quality of therapeutic stimuli delivered to the patient. Methods: Nine clinically healthy adult horses (mean body mass: 388 kg) routinely employed in hippotherapy were evaluated. Two healthy female physiotherapists trained in hippotherapy (26 and 27 years; 50.9 and 51.3 kg) served as riders in all experimental conditions. Surface electromyography (sEMG) was recorded bilaterally from the Rectus Abdominis (RA) and External Oblique Abdominis (EOA) muscles during walking at a constant speed of 1.43 m/s under three randomized conditions: without rider (WR), single rider (R1), and double riding (R2). Each trial consisted of a 10-s stable walking period. Data were analyzed using randomized block ANOVA with Tukey’s post hoc tests and effect size estimates (Cohen’s d and Hedges’ g ). Results: Compared with WR, double riding (R2) resulted in significantly greater activation of both RA and EOA muscles bilaterally ( p < 0.05), with large effect sizes ( g = 1.50–2.52). No significant differences were observed between R1 and WR when rider load did not exceed 14.75% of the horse’s body weight. Comparisons between R2 and R1 revealed asymmetric activation patterns, particularly increased activation of the left EOA and right RA muscles ( p < 0.05; large effect sizes), suggesting compensatory neuromuscular strategies to maintain trunk stability under increased load and movement. Conclusions: Single riding with light loads does not substantially alter equine abdominal muscle activity during walking. In contrast, double riding increases muscular demand and induces asymmetric activation patterns, which may reflect compensatory mechanisms related to load magnitude, rider movement, and handling configuration. These findings have important implications for equine welfare and for optimizing therapeutic decision-making in hippotherapy practice.

This study investigated the effects of a foot core intervention on the coordination of foot joints in recreational runners. This was a secondary analysis from a randomized controlled trial conducted with 87 recreational runners allocated to the control group (CG), which followed a placebo lower limb stretching protocol, or the intervention group (IG), which underwent an 8-week (3 times/week) foot core training. The participants ran on a force-instrumented treadmill at a self-selected speed (9.5-10.5 km/h) while the foot segment motion was captured. The vector coding technique was used to assess inter-joint coordination for four selected coupled segment and joint angles. The coordination patterns of the calcaneus and midfoot (CalMid) and midfoot and metatarsus (MidMet) joint pairs were affected. In the frontal plane, IG showed an in-phase with proximal dominancy coordination at heel strike, with a decrease in its frequency after the training (P=0.018), suggesting a longer foot supination. Additionally, IG showed an anti-phase with distal dominancy pattern at early stance compared to CG due to a smaller but earlier inversion of the CalMid-MidMet pair (P=0.020). The intervention also had an effect on the transverse plane of the CalMid-MidMet pair, with IG showing a significantly greater frequency of anti-phase coordination with proximal dominancy during propulsion than CG (P=0.013), probably due to a reduction in the CalMid abduction. Overall, the results suggested that the foot core intervention reduces the occurrence of running-related injuries by increasing the resistance to calcaneus pronation and building a more rigid and efficient lever during push-off.

(1) Background: The dynamics of hand tremors involve nonrandom and short-term motor patterns (STMPs). This study aimed to (i) identify STMPs in Parkinson’s disease (PD) and physiological resting tremor and (ii) characterize STMPs by amplitude, persistence, and regularity. (2) Methods: This study included healthy (N = 12, 60.1 ± 5.9 years old) and PD (N = 14, 65 ± 11.54 years old) participants. The signals were collected using a triaxial gyroscope on the dorsal side of the hand during a resting condition. Data were preprocessed and seven features were extracted from each 1 s window with 50% overlap. The STMPs were identified using the clustering technique k-means applied to the data in the two-dimensional space given by t-Distributed Stochastic Neighbor Embedding (t-SNE). The frequency, transition probability, and duration of the STMPs for each group were assessed. All STMP features were averaged across groups. (3) Results: Three STMPs were identified in tremor signals (p < 0.05). STMP 1 was prevalent in the healthy control (HC) subjects, STMP 2 in both groups, and STMP3 in PD. Only the coefficient of variation and complexity differed significantly between groups. (4) Conclusion: These results can help professionals characterize and evaluate tremor severity and treatment efficacy.

(1) Background: One of the main cardinal signs of Parkinson’s disease (PD) is rigidity, whose assessment is important for monitoring the patient’s recovery. The wrist is one of the joints most affected by this symptom, which has a great impact on activities of daily living and consequently on quality of life. The assessment of rigidity is traditionally made by clinical scales, which have limitations due to their subjectivity and low intra- and inter-examiner reliability. (2) Objectives: To compile the main methods used to assess wrist rigidity in PD and to study their validity and reliability, a scope review was conducted. (3) Methods: PubMed, IEEE/IET Electronic Library, Web of Science, Scopus, Cochrane, Bireme, Google Scholar and Science Direct databases were used. (4) Results: Twenty-eight studies were included. The studies presented several methods for quantitative assessment of rigidity using instruments such as force and inertial sensors. (5) Conclusions: Such methods present good correlation with clinical scales and are useful for detecting and monitoring rigidity. However, the development of a standard quantitative method for assessing rigidity in clinical practice remains a challenge.