Banca de DEFESA: Alessandra Martins Melo de Sousa

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Alessandra Martins Melo de Sousa
DATE: 23/08/2022
TIME: 14:00
LOCAL: Microsoft Teams
TITLE:

"THE INFLUENCE OF HIP AND KNEE JOINT ANGLES POSITIONS ON QUADRICEPS MUSCLE-TENDON UNIT PROPERTIES DURING MAXIMAL VOLUNTARY ISOMETRIC CONTRACTION."

KEY WORDS:
PAGES: 28
BIG AREA: Outra
AREA: Defesa
SUMMARY:

There are several disorders that specifically affect knee integrity in young individuals and the exercise is a powerful intervention to treat knee disorders. However, studies do not make it clear which is the best positioning choice, whether seated or supine position, with 60º knee flexion, allowing greater force production or prioritizing 20º knee flexion to lowest articular stress. Determining how the muscle-tendon unit quadriceps femoris acts according to hip and knee joints angles can help the clinicians in joint angle choice during rehabilitation proposals. We aimed to investigate the influence of the hip and knee joints angles on maximal voluntary isometric contraction (MVIC) of the knee extensors, electrical activity and neuromuscular efficiency, muscle architecture and stiffness of the tendon-aponeurosis complex (TAC) of all constituents of the quadriceps femoris and patellar tendon properties. Twenty young males were evaluated in four positions: supine with knee flexion at 60º (SUP60); seated with knee flexion at 60º (SIT60); supine with knee flexion at 20º (SUP20); and seated with knee flexion at 20º (SIT20). Knee extensors MVIC, quadriceps femoris Ultrasound was used to determine in the quadriceps femoris: a) muscle architecture (at rest and during MVIC) [pennation angle (θp), fascicle lenght (Lf)], b) TAC stiffness, and patellar tendon morphological, mechanical and material properties were evaluated. MVIC torque and neuromuscular efficiency were higher for SUP60 and SIT60 compared to SUP20 and SIT20 position. We found higher Lf and lower θp in positions with the knee flexed at 60º. The TAC, tendon force, stiffness, stress, and Young's modulus were greater in more elongated positions than in shortened positions. Stretching was greater in SIT20 compared to SUP20. Muscle electrical activity, tendon length, strain and CSA remained unchanged. In conclusion, clinicians should preferably use positions at 60° of knee flexion rather than 20°, regardless seated or supine position during MVIC in rehabilitation proposals to greater muscle force production and stiffer tendons. ClinicalTrials.gov (Identifier: NCT03822221). Keywords: Moment-angle relationship; Muscle length; Mechanical properties; Knee extension force; Tendon-aponeurosis complex . 

BANKING MEMBERS:
Presidente - 1962055 - RITA DE CASSIA MARQUETI DURIGAN
Interna - 1772842 - PATRICIA AZEVEDO GARCIA
Externo à Instituição - RODRIGO SCATTONE DA SILVA
Externo à Instituição - MARCO AURELIO VAZ - UFRGS