Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Heliyon ; 10(17): e36338, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39281584

RESUMO

Background: The consensus on anterior cruciate ligament (ACL) injury prevention involves the suppression of dynamic knee valgus (DKV). The gold standard for evaluating the DKV includes three-dimensional motion analysis systems; however, these are expensive and cannot be used to evaluate all athletes. Markerless motion-capture systems and joint angle calculations using posture estimation have been reported. However, there have been no reports on the reliability and validity of DKV calculations using posture estimation. Research question: This study aimed to clarify the reliability and validity of DKV calculation using posture estimation. Methods: Fifteen participants performed 10 single-leg jump landings from a height of 20 cm, and the knee joint angle was calculated using joint points measured using machine learning (MediaPipe Pose) and motion-capture systems (VICON MX). Two types of angle calculation methods were used: absolute value and change from the initial ground contact (IC). Intra- and inter-rater reliabilities were examined using intraclass correlation coefficients, and concurrent validity was examined using Pearson's correlation coefficients. To examine intra-examiner reliability, we performed single-leg jump landings at intervals of ≥3 days. Results: The calculation by MediaPipe Pose was significantly higher than that by the 3-D motion analysis systems (p < 0.05, error range 18.83-19.68°), and there was no main effect of knee valgus angle or time on the excursion angle from IC (p > 0.05). No significant concurrent validity was found in the absolute value, which was significantly correlated with the change in IC. Although the inter-rater reliability of the absolute value was low, the change in IC showed good reliability and concurrent validity. Significance: The results of this research suggest that the DKV calculation by pose estimation using machine learning is practical, with normalization by the angle at IC.

2.
Exp Gerontol ; 98: 153-161, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28803135

RESUMO

Aging is known to lead to the impaired recovery of muscle after disuse as well as the increased susceptibility of the muscle to damage. Here, we show that, in the older rats, reloading after disuse atrophy, causes the damage of the muscle fibers and the basement membrane (BM) that structurally support the muscle fibers. Male Wistar rats of 3-(young) and 20-(older) months of age were subjected to hindlimb-unloading for 2weeks followed by reloading for a week. In the older rats, the soleus muscles showed necrosis and central nuclei fiber indicating the regeneration of muscle fibers. Furthermore, ectopic immunoreactivity of collagen IV, a major component of the BM, remained mostly associated with the necrotic appearance, suggesting that the older rats were impaired with the ability of repairing the damaged BM. Further, after unloading and reloading, the older rats did not show a significant alteration, although the young rats showed clear response of Col4a1 and Col4a2 genes, both coding for collagen IV. In addition, during the recovery phase, the young rats showed increase in the amount of Hsp47 and Sparc mRNA, which are protein folding-related factor genes, while the older rats did not show any significant variation. Taken together, our findings suggest that the atrophic muscle fibers of the older rats induced by unloading were vulnerable to the weight loading, and that attenuated reactivity of the BM-synthesizing fibroblast to gravity contributes to the fragility of muscle fibers in the older animals.


Assuntos
Envelhecimento/metabolismo , Membrana Basal/metabolismo , Contração Muscular , Músculo Esquelético/metabolismo , Atrofia Muscular/metabolismo , Fatores Etários , Envelhecimento/genética , Envelhecimento/patologia , Animais , Membrana Basal/ultraestrutura , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica , Proteínas de Choque Térmico HSP47/genética , Proteínas de Choque Térmico HSP47/metabolismo , Elevação dos Membros Posteriores , Masculino , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/ultraestrutura , Força Muscular , Músculo Esquelético/fisiopatologia , Músculo Esquelético/ultraestrutura , Atrofia Muscular/genética , Atrofia Muscular/patologia , Atrofia Muscular/fisiopatologia , Necrose , Osteonectina/genética , Osteonectina/metabolismo , Ratos Wistar , Recuperação de Função Fisiológica , Fatores de Tempo
3.
World J Surg Oncol ; 14(1): 176, 2016 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-27368929

RESUMO

BACKGROUND: Leiomyosarcomas typically originate in smooth muscle cell. Leiomyosarcoma potentially arising from the adrenal gland is an extremely rare mesenchymal tumors associated with delayed diagnosis and poor prognosis. CASE PRESENTATION: A 34-year-old man visited our department complaining of right hypochondriac pain. Computed tomography demonstrated a solid mass measuring 5.2 cm in diameter above the right kidney, corresponding to the right adrenal gland, and a lymph node mass, which appeared to have invaded the IVC wall. Right adrenalectomy and lymphadenectomy were performed. A microscopic examination revealed primary adrenal leiomyosarcoma with lymph node metastasis. No adjuvant therapy was performed, and the patient remains recurrence-free at 10 months postoperatively. CONCLUSIONS: We experienced a very rare case of primary adrenal leiomyosarcoma. Aggressive surgical resection including vascular reconstruction may be associated with improved survival.


Assuntos
Neoplasias das Glândulas Suprarrenais/patologia , Leiomiossarcoma/patologia , Neoplasias das Glândulas Suprarrenais/diagnóstico , Neoplasias das Glândulas Suprarrenais/cirurgia , Adrenalectomia , Adulto , Humanos , Leiomiossarcoma/diagnóstico , Leiomiossarcoma/cirurgia , Excisão de Linfonodo , Metástase Linfática , Masculino
4.
Parkinsonism Relat Disord ; 12(2): 97-102, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16256407

RESUMO

The present study investigated the effects of external cues on motor control of the ankle joint during gait initiation in patients with Parkinson's disease (PD) and in age-matched healthy subjects. The soleus H-reflexes were recorded during self-generated and cue-triggered gait initiation. The tibialis anterior muscle burst during cue-triggered gait initiation was found to be significantly larger than that during self-generated gait initiation in both groups. External cues significantly increased soleus H-reflex depression during gait initiation in PD patients, although this significant increase was not present in healthy subjects. These findings indicate that external cues affect motor control of the extensor muscle of the ankle joint during gait initiation in PD patients.


Assuntos
Tornozelo/fisiologia , Sinais (Psicologia) , Marcha/fisiologia , Doença de Parkinson/fisiopatologia , Idoso , Fenômenos Biomecânicos , Eletromiografia , Feminino , Reflexo H/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Movimento/fisiologia , Músculo Esquelético/fisiopatologia , Desempenho Psicomotor/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA