Percorrer por autor "Oliveira, Raúl"
A mostrar 1 - 10 de 13
Resultados por página
Opções de ordenação
- O efeito das ligaduras funcionais da articulação tíbio-társica na propriocepção: revisão da literaturaPublication . Esteves, José Manuel; Melo, Filipe; Oliveira, Raúl; Cabri, JanIntrodução: A ligadura funcional na articulação tíbio-társica é utilizada com fins terapêuticos ou preventivos. A sua eficácia pode ser atribuída à limitação mecânica que implica, mas também pode envolver processos neurofisiológicos relacionados com o feedback proprioceptivo. Existem instrumentos de medida que avaliam objectivamente algumas componentes da propriocepção. Objectivos: Realizar uma revisão da literatura sobre o efeito das ligaduras funcionais da articulação tíbio-társica na propriocepção. Relevância: O conhecimento sobre o tema pode constituir mais uma informação que contribui para decisão dos fisioterapeutas ou outros profissionais de saúde quanto à aplicação da ligadura funcional na articulação tíbio-társica. Metodologia: Com base numa metodologia sistemática, foi realizada uma revisão dos artigos publicados entre 1987 e 2007, pesquisados nas bases de dados referenciais PubMed e PEDro. Foram seleccionados os artigos que cumpriam com os critérios de selecção e eliminados os restantes. Resultados e discussão: Dos 66 artigos provenientes das pesquisas, foram seleccionados 10 artigos. Constatou-se que cinco artigos referem que as ligaduras funcionais não apresentam qualquer efeito sobre a propriocepção. Um estudo verificou alterações benéficas que desapareciam após o exercício físico. Dois estudos referem que a ligadura funcional poderá intervir positivamente nos sistemas proprioceptivos implicados na estabilidade dinâmica. Apenas um estudo refere que a ligadura poderá ter um efeito prejudicial sobre a propriocepção. Conclusão: Os resultados dos estudos não são unânimes quanto aos efeitos da ligadura funcional da articulação tíbio-társica na propriocepção. É necessária a realização de mais estudos com desenhos experimentais de maior qualidade metodológica.
- Evolving dynamics of neck muscle activation patterns in dental students : a longitudinal studyPublication . Almeida, Manuel Barbosa de; Moreira, Marion; Miranda-Oliveira, Paulo; Moreira, José; Família, Carlos; Vaz, João R.; Moleirinho-Alves, Paula; Oliveira, RaúlCervical pain has been linked to increased motor unit activity, potentially associated with the initiation and progression of chronic neck pain. Therefore, this study aimed to compare the time-course changes in cervical superficial muscle activation patterns among dental students with and without neck pain throughout their initial semester of clinical training. We used an online Nordic Musculoskeletal Questionnaire for group allocation between neck pain (NP) (n = 21) and control group (CG) (n = 23). Surface electromyography (sEMG) of the sternocleidomastoid and upper bilateral trapezius was recorded before starting their clinical practice and after their first semester while performing a cranio-cervical flexion test (CCFT) in five increasing levels between 22 mmHg and 30 mmHg. After the first semester, both the CG (p < 0.001) and NP (p = 0.038) groups showed decreased sternocleidomastoid activation. The NP group exhibited a concomitant increase in upper trapezius coactivation (p < 0.001), whereas the muscle activation pattern in asymptomatic students remained unchanged (p = 0.980). During the first semester of clinical training, dental students exhibited decreased superficial flexor activity, but those with neck pain had increased co-contraction of the upper trapezius, likely to stabilize the painful segment. This altered activation pattern could be associated with further dysfunction and symptoms, potentially contributing to chronicity.
- Hamstring muscles volume of elite football athletes assessed using magnetic resonance imagingPublication . Firmino, Telmo; Santos, F; Abrantes, F; Til Perez, L; Mascarenhas, V; Mendes, B; Vaz, João R; Oliveira, Raúl; Martins, A; Freitas, Sandro
- Hamstring stiffness and strength responses to repeated sprints in healthy nonathletes and soccer players with versus without previous injuryPublication . Freitas, Sandro R.; Radaelli, Régis; Vaz, João R.; Oliveira, RaúlBackground: The effect of 10 × 30 m repeated sprints on passive and active stiffness of semitendinosus (ST) and biceps femoris long head (BFlh), and knee flexor maximal voluntary isometric contraction (MVIC) and rate of force development (RFD), and whether athletes with previous hamstring injury have a different response, is unknown. Hypothesis: Repeated sprints would (1) increase BFlh stiffness and decrease ST stiffness and knee flexors MVIC and RFD in healthy participants; and (2) greater magnitude of response would be seen in athletes with previous hamstring injury. Study Design: Case series (experiment I) and case control (experiment II) study designs. Level of Evidence: Level 3. Methods: Healthy nonathletes attended 2 replicated sessions (experiment I, n = 18), while soccer players with (n = 38) and without (n = 67) previous hamstring injury attended 1 testing session (experiment II). Results: In both experiments, the knee flexors MVIC and RFD decreased after the sprints (P < 0.05). In experiment I, the ST and BFlh passive stiffness reduced after the sprints (P < 0.02), while a small BFlh active stiffness increase was noted (P = 0.02); however, no correlation was observed between the 2 testing sessions for the postsprint muscle stiffness responses (r = -0.07-0.44; P > 0.07). In experiment II, only an ST passive stiffness reduction was observed after the sprints (P < 0.01). No differences were noted between injured and noninjured lower limbs for any variable (P > 0.10). Conclusion: Repeated sprints are likely to decrease the knee flexor’s maximal and rapid strength, and to alter the hamstring stiffness in the nonathlete population. Previous hamstring injury does not apparently affect the footballer’s hamstring functional and mechanical responses to repeated sprints. Clinical Relevance: The responses of hamstring stiffness and knee flexor strength to repeated sprints are unlikely to be associated with hamstring injury.
- Hamstring stiffness pattern during contraction in healthy individuals: analysis by ultrasound-based shear wave elastographyPublication . Mendes, Bruno; Firmino, Telmo; Oliveira, Raúl; Neto, Tiago; Infante, Jorge; Vaz, João R; Freitas, SandroPurpose To assess the stiffness of hamstring muscles during isometric contractions in healthy individuals, using ultrasoundbased shear wave elastography to (1) determine the intra- and inter-day assessment repeatability, (2) characterize the stiffness of semitendinosus (ST) and biceps femoris long head (BFlh) along the contraction intensity, and (3) characterize stiffness distribution among the hamstring muscles and inter-limb symmetry. Methods Two experiments were conducted. In experiment I (n = 12), the intra-day repeatability in assessing the BFlh and ST stiffness were determined at intensities between 10–60% of maximal voluntary isometric contraction (MVIC) in a single session. In experiment II (n = 11), the stiffness of the hamstring muscles of both thighs was assessed at 20% of MVIC in the first session; and retested (for one randomly chosen thigh) in a second session. Isometric contraction of knee flexors was performed with the knee flexed at 30° and with the hip in a neutral position. Results Moderate-to-very-high intra- and inter-day repeatability was found (ICC = 0.69–0.93). The BFlh/ST stiffness ratio increased with contraction intensity. At 20% of MVIC, the ST showed the highest stiffness among the hamstring muscles (p < 0.02), with no differences between the remaining hamstring muscles (p > 0.474). No differences were found between limbs (p = 0.12). Conclusions The stiffness distribution among the hamstring muscles during submaximal isometric contractions is heterogeneous, but symmetric between limbs, and changes depending on the contraction intensity. Shear wave elastography is a reliable tool to assess the stiffness of hamstring muscles during contraction.
- Muscle activity variability patterns and stride to stride fluctuations of older adults are positively correlated during walkingPublication . Jordão, Sofia; Stergiou, Nick; Brandão, Rita; Pezarat-Correia, Pedro; Oliveira, Raúl; Cortes, Nelson; Vaz, João R.It has been found that fractal-like patterns are present in the temporal structure of the variability of healthy biological rhythms, while pathology and disease lead to their deterioration. Interestingly, it has recently been suggested that these patterns in biological rhythms are related with each other, reflecting overall health or lack of it, due to their interaction. However, the underlying neurophysiological mechanisms responsible for such dependency remain unknown. In addition, this relationship between different elements needs to be first verified before we even pursue understanding their interaction. This study aimed to investigate the relationship between two elements of the neuromuscular system, gait and muscle activity variability patterns in older adults. Twenty-one older adults walked at their preferred walking speed on a treadmill. Inter-stride intervals were obtained through an accelerometer placed on the lateral malleoli to assess the temporal structure of variability of stride-to-stride fluctuations. Inter muscle peak intervals were obtained through the electromyographic signal of the gastrocnemius to assess the temporal structure of the variability of the simultaneous muscle activity. The temporal structure of variability from both signals was evaluated through the detrended fluctuation analysis, while their magnitude of variability was evaluated using the coefficient of variation. The Pearson’s Correlation coefficient was used to identify the relationship between the two dependent variables. A significant strong positive correlation was found between the temporal structure of gait and muscle activity patterns. This result suggests that there is an interdependency between biological rhythms that compose the human neuromuscular system.
- Neck strength variations in dental students with and without neck pain : a longitudinal studyPublication . Almeida, Manuel Barbosa; Moreira, Marion; Moleirinho-Alves, Paula; Oliveira, RaúlNeck pain can induce specific motor responses and alterations in muscle strength. Therefore, this study aimed to investigate and compare the progression of cervical muscle strength within and between students with and without neck pain over the course of their first semester of clinical training. We used an online Nordic Musculoskeletal Questionnaire for group allocation, and neck strength in flexion, extension, and lateral flexion on both sides was measured using the KForce Bubble Pro hand-held dynamometer. Forty-four students were divided into neck pain (n = 21) and asymptomatic (n = 23) groups. Both groups increased neck strength by the end of the semester in flexion, extension, and left and right lateral flexion (p < 0.001). Students experiencing neck pain showed a significantly lesser degree of improvement (p = 0.036) in right lateral flexion. The agonist/antagonist ratios revealed an enhanced role of neck extensors across both groups. Dental students showed overall increased cervical strength in their first semester of clinical training. Those with neck pain exhibited a diminished rate of strength gain in right lateral flexion when compared with students without pain by the semester’s end, suggesting different neuromuscular adjustments to clinical practice in students experiencing pain, which may lead to functional impairments in later training stages.
- Noninvasive measurement of sciatic nerve stiffness in patients with chronic low back related leg pain using shear wave elastographyPublication . Neto, Tiago; Freitas, Sandro; Andrade, Ricardo; Vaz, João R; Mendes, Bruno; Firmino, Telmo; Bruno, Paula; Nordez, Antoine; Oliveira, RaúlObjectives—The purpose of this study was to determine whether sciatic nerve stiffness is altered in people with chronic low back–related leg pain by using shear wave elastography. Methods—In this cross-sectional study, the sciatic nerve shear wave velocity (ie, an index of stiffness) was measured in both legs of 16 participants (8 with unilateral low back–related leg pain and 8 healthy controls). Sciatic stiffness was measured during a passive ankle dorsiflexion motion performed at 28/s in an isokinetic dynamometer. The ankle range of motion and passive torque, as well as muscle activity, were also measured. Results—In people with low back–related leg pain, the affected limb showed higher sciatic nerve stiffness compared to the unaffected limb (111.3%; P5.05). However, no differences were observed between the unaffected limb of people with low back–related leg pain and the healthy controls (P5.34). Conclusions—People with chronic low back–related leg pain have interlimb differences in sciatic nerve stiffness, as measured by a safe and noninvasive method: shear wave elastography. The changes found may be related to alterations in nerve mechanical properties, which should be confirmed by future investigations.
- Prevalence of musculoskeletal disorders among dental students : a systematic review and meta-analysisPublication . Almeida, Manuel Barbosa; Póvoa, Rita; Tavares, Duarte; Alves, Paula Moleirinho; Oliveira, RaúlObjectives: This study aimed to determine the prevalence of work-related musculoskeletal disorders (WMSDs) in dental students and analyze the potential associated risk factors. Methods: This review was registered in PROSPERO with the number CRD42022349864. We performed a meta-analysis calculating event rates with relative 95% confidence intervals for each body region. Two investigators systematically searched Cochrane, Pubmed, Scopus, and EBSCO databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results: Sixteen studies, with 3761 dental students, were included. The highest 7-day prevalence was in the lower back (27.2%; 95% CI 20–35), neck (27%; 95% CI 19.1–35.8), and upper back (24.2%; 95% CI 17.2–32). Yearly occurrence was mainly in the neck (51%; 95% CI 41–61), followed by shoulders (45.3%; 95% CI 37.6–53.1) and lower back (42%; 95% CI 34.1–50.2) and a fraction of these reported that symptoms in lower-back (15.2%; 95% CI 12.1–18.5), neck (13.9%; 95% CI 10.6–17.5) and shoulders (12.2%; 95% CI 8.7–16.3) affected work or normal activities. Associated contributing factors include female sex, poor posture habits, inadequate ergonomics knowledge, sedentary lifestyle, high physical activity levels, poor quality of life, and smoking. In contrast, engaging in physical exercise has positively impacted mitigating the risk of musculoskeletal disorders. Conclusions: WMSDs have a high prevalence among dental students, particularly in the cervicothoracic, lumbar, and shoulder regions, having a significant impact since training years. Further research with a multidimensional approach with psychosocial and physical assessments is recommended to understand this issue thoroughly.
- The immediate effects of a dynamic orthosis on gait patterns in children with unilateral spastic cerebral palsy: a kinematic analysisPublication . Martins, Maria Elisabete; Cordovil, Rita; Oliveira, Raúl; Pinho, Joana; Diniz, Ana; Vaz, João RThis study analyzes the immediate effects of wearing a Therasuit on sagittal plane lower limb angular displacements during gait in children with unilateral spastic cerebral palsy (US-CP). Seven participants (median age = 7.00 years; ranging from 5.83 to 9.00 years) with US-CP, levels I and II of the Gross Motor Function Classification System, were assessed with kinematic gait analysis in three different conditions: (A) Baseline; (B) Therasuit without elastics and (C) Therasuit with elastics. Significant improvements were observed at the hip joint of both lower limbs during most of the gait cycle in participants wearing a Therasuit, including a decrease in the flexion pattern at the initial contact and swing phase in both lower limbs, and an increase in the extension pattern in the paretic lower limb during the stance phase. At the knee joint in the paretic lower limb, significant differences were found between the baseline and Therasuit with elastics conditions on the knee angle at initial contact, and between baseline and both Therasuit conditions on the flexion angle at swing phase. However, the inter-individual variability in kinematic patterns at the knee joint was high. At the ankle joint, decreased plantar flexion at initial contact and increased dorsiflexion during stance and swing phases were observed at the Therasuit with elastics condition, helping to correct the equinus-foot in the paretic lower limb during the whole gait cycle. The Z-values showed large effect sizes particularly for most of the angular hip variables in both lower limbs and for the angular ankle variables in the paretic lower limb. The Therasuit seems to have some positive immediate effects on gait kinematics in children with spastic unilateral cerebral palsy by providing a more functional and safer gait pattern. Future investigations with larger samples are recommended to further support these findings.