Influence of menstrual cycle on electromyographic activity and knee kinematics during jump landing

• Grant number: 07/02272-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: September 01, 2007
• End date: February 28, 2009
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Fábio Viadanna Serrão
• Grantee: Guilherme Manna Cesar
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Anterior cruciate ligament (ACL) injury in women has brought a great deal of attention in the past years. The reason involves the fact that women are two to eight times more prone to sustain injuries to this structure than men when participating in similar activities. The influence of female sexual hormones on ligament laxity has been referred to as one of the factors of this incidence. The dynamic knee valgus, which is controlled by the muscle gluteus medius, is observed during landings from a jump and it characterizes the main ACL injury mechanism. Besides the dynamic valgus, knee flexion angle, which is controlled by the muscles quadriceps and hamstrings, also presents importance concerning the dissipation of ground reaction forces during landing from a jump. Although differences are indicated in studies regarding the dynamic valgus amplitude, the knee flexion angle, and the neuromuscular control between women and men, few studies assessed the behavior of these variables on the different phases of the menstrual cycle. Moreover, studies assessing the gluteus medius control under the effect of hormonal oscillation observed during the menstrual cycle were not found. Therefore, the objectives of this study are: 1. Assess the electrical activity (electromyographic signal onset timing and integral) of the muscles gluteus medius, rectus femoris, and biceps femoris; and 2. Assess maximal amplitude of dynamic knee valgus and knee flexion angle. These variables will be assessed during a single-leg landing on different phases of the menstrual cycle. In this study with random sample allocation, 20 health, active and non-athlete volunteers will participate, presenting the Test Power of approximately 95% with alpha = 0,05 and p = 15%. The measurement of plasmatic concentrations of estrogen and progesterone hormones will occur in three different phases of the menstrual cycle (early follicular, late follicular and luteal). Simultaneously to this measurements, kinematic analysis of the single-leg landing from a 31cm platform associated to the electromyographic assessment of the muscles gluteus medius, rectus femoris, and biceps femoris will take place. A descriptive data analysis will be executed, along with punctual and interval estimation of the parameters of interest. For treatment comparison the analysis of variance will be executed with each woman representing one block. If the data do not satisfy the conditions necessary for this parametric analysis of variance, convenient transformations will be utilized and/or a non-parametric analysis of variance (Friedmann test). It is expected, with this research project, to contribute to a better understanding of some of the main clinical aspects involving ACL injuries in women, as well as the functional and preventive aspects regarding the injuries of this structure. It is also expected with the execution of this project to provide guidelines to a more efficient and cautiously physical therapy intervention steps, considering the different phases of the menstrual cycle.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CESAR, GUILHERME MANNA; PEREIRA, VANESSA SANTOS; PEREIRA SANTIAGO, PAULO ROBERTO; BENZE, BENEDITO GALVAO; LOBO DA COSTA, PAULA HENTSHEL; AMORIM, CESAR FERREIRA; SERRAO, FABIO VIADANNA. Variations in dynamic knee valgus and gluteus medius onset timing in non-athletic females related to hormonal changes during the menstrual cycle. KNEE, v. 18, n. 4, p. 224-230, AUG 2011. (07/02272-7)