The Effect of Phases of the Menstrual Cycle on Frontal PlaneKnee Kinematics During Landing

Jacalyn J Robert-McComb; C RogerJames; Jennifer Merkle Ford; Reid Norman; Greg Dedrick

Jacalyn J Robert-McComb¹, C RogerJames², Jennifer Merkle Ford¹, Reid Norman², Greg Dedrick²

¹Texas Tech University, Lubbock, Texas, USA

²Texas Tech University Health Science Center, Lubbock, Texas, USA

^*Corresponding author: Jacalyn J Robert-McComb, Departmentof Health, Exercise, and Sport Sciences, Texas Tech University, Lubbock, TX 79409-3011, USA. Tel: +18068346306; +18067981073; +18067421688; Email: jacalyn.Mccomb@ttu.edu

Received Date: 19 August, 2017; Accepted Date: 07 September, 2017; Published Date: 14 September, 2017

1. Abstract

Knee valgus, a known Anterior Cruciate Ligament (ACL) injury risk factor, is subject to hormonal changes during the menstrual cycle. Therefore, the purposeof this study was to analyze 2D frontal plane knee kinematics during drop-jump landing across phases of the human menstrual cycle (days 1-3;11-13;21-23). Twenty-seven (18-25 years) females with normal menstrual cycles initially met inclusion criteria for study participation. Twenty two-females were used for data analysis.The protocol consisted of drop-jumps from a 50cm platform while the participant’s frontal plane movement was recorded using a single digital video camera (60 Hz). The initial time period for data collection was counterbalanced across days of the menstrual cycle and randomized. The procedures were identical for all repeated testing.Two separate one-way repeated measures ANOVAs were used to analyze landing patterns. Alpha was set at .05. There was a significant difference for valgus knee angle among days 1-3, 11-13, and 21-24 of the menstrual cycle, F(2, 42) = 3.92, p = .037. Post-hoc tests revealed a significant difference for valgus knee angle between days 1-3 and days 11-14, t(21) = 2.733, p = .012.No other significant differences were found. The largest magnitude of valgus knee angleoccurred during the late follicular phase (days 11-14) of the menstrual cycle, when there was a large spike in estradiol.

2. Keywords: ACL Injury; Human Menstrual Cycle; Landing Pattern; Valgus Knee Angle

Figure 1: Changes in Hormonal Levels during a Normal Menstrual Cycle.

Figure 2: Retroreflective Markers on Participants.

Figure 3: Mean Knee Distance.

Figure 4: Mean Valgus Knee Angle.

Variable	M ± SD	Range
Age	20.18 ± 1.82	18-24
Height (cm)	165.97± 5.42	158.8-180.3
Weight (kg)	64.22 ± 14.79	49.9-120
Activity level scale	5.23 ± 1.27	04-Aug
Age Began Menses	13.27 ± 1.08	Nov-15
Number of days of cycle	5.23 ± 1.27	03-Aug
Number of days between cycles	28.27±1.45	26-31
Leg Length (cm)	85.41±3.27	82-94
Tibial Length (cm)	38.60±1.94	34.5-43
Craig’s test (degrees)	10.19±0.89	9.25-13.50
Quadriceps angle (degrees)	16.14±1.13	15-20
Hematocrit (%)	41.59±2.52	39-50

Table 1: Descriptive Characteristics of Subjects (N=22).

	Early Follicular	Late Follicular	Mid-Luteal
Estradiol (pg/ml)	61±22.15	159±27.95	132±19.30
Estradiol (pg/ml)	(16.07-95.6)	(39.21-563.49)	(50.01-530.52)
Progesterone (ng/ml)	0.65±0.09	1.20±0.41	11.10±1.54
Progesterone (ng/ml)	(0.16-1.93)	(0.19-4.06)	(1.07-24.51)
Testosterone (ng/ml)	0.26±0.02	0.34±0.03	0.36±0.04
Testosterone (ng/ml)	(0.15-0.58)	(0.18-0.84)	(0.17-0.91)
Note: Values are M ± SD with the range in parentheses

Table 2: Hormone Levels by Cycle Phase (N=22).

	Early Follicular	Late Follicular	Mid-Luteal
Knee Distance (cm)	32.92±4.55	32.32 ±4.37	33.03±4.61
Knee Distance (cm)	(26.43-45.85)	(24.77-45.60)	(27.21-45.86)
Knee Angle (degrees)	−7.83±5.74	−9.70±7.26	−7.53±6.44
Knee Angle (degrees)	(−.47- −25.92)	(−3.22- −31.91)	(1.23- −31.07)
Note: Values are M ± SD with the range in parentheses