1. Comparison of Isokinetic Knee Extension/Flexion Strength Ratios in High School Male and Female Athletes
Adam MacDonald, Nic Truscott
Wenatchee High School
Wenatchee, WA
Presentation for NATA National Conference
Dallas, TX June 17, 2002

2. Objective
Purpose: To compare knee extension/flexion strength ratios in male and female high school athletes
Goal: To examine the ratio of strength between quadricep and hamstring strength in high school aged male and female athletes

3. Research Setup Warm-Up Before Testing:
5 Minutes of Biking at 50 Watts on Monark 818 E Ergomedic Stationary Bike
2-3 Minutes Quadriceps/Hamstring Stretches
2 Reps at 60°and 180° at 50% prior to each respective test

4. Data Collection
Data was collected using the Lido® Active (Loredan, West Sacramento, CA).

5. Subjects Subjects were healthy high school student volunteers,
Male, n=18, Female, n=18;
 Age=16.06±1.94 years;
 Height=171.60±6.56 cm;
 Weight=67.37±6.78 kg.

6. Data Collected Data was collected for: Peak Flexion Torque Left/Right;
Peak Extension Torque Left/Right;
Average Flexion Torque Left/Right;
Average Extension Torque Left/Right.

7. Analysis The Single Variable ANOVA Analysis <p=.05> Results:
No significant difference between males (56.59%) and females (55.14%) at 60 degrees/sec in knee extension/flexion ratio
At 180 degrees/sec, females (66.40%) exhibited a significantly higher knee extension/flexion ratio than males (58.69%)

8. Conclusions
Higher knee extension/flexion ratio in females at 180 degrees/sec due to lower relative quadricep muscles power; not due to higher hamstring power
There was no significant difference in knee extension/flexion ratios between males and females at 60 degrees/sec among these groups
The overall numbers at 60 degrees/sec may indicate some weakness in the hamstrings as compared to the quadriceps

9. Further Conclusions
Many sources advocate that the hamstrings should be 67% or 2/3 the strength of the quadriceps. Both males and females were 10% or more below this mark
We feel functional hamstring strengthening would improve this overall ratio and may ultimately assist in the prevention of knee and thigh injuries

10. Thank You To:
Mr. Bill Eagle, AP Calculus Instructor at Wenatchee High School for analysis assistance
The Students of Wenatchee High School in Wenatchee, WA for their volunteer participation