Methods: Ten subjects used were an average age of 22 and ranged from 18-24. These subjects ran an average of 15 miles a week and had no injuries within the last 3 years. During the testing, these subjects wore their regular running shoes. Prior to the testing, the subjects warmed up and stretched. Then, they were asked to run an average of 20 yards on concrete and grass while being taped. Each joint angle was indicated using tape. The results were then analyzed through KA Video.

Results: Using a two sample independent t-test with the degrees of freedom of 18 and a critical t of 2.101. Anything equal to or above the critical t, the null hypothesis was rejected, stating there was a significant difference. The results were showed:
 
  Wrist Elbow Shoulder Hip Knee Ankle
Heel Down t=.04 t=.11 t=2.32 t=2.61 t=2.47 t=2.63
Mid-stance t=.19 t=.41 t=.02 t=.23 t=2.30 t=2.45
Toe off t=.21 t=3.21 t=2.43 t=2.42 t=2.81 t=2.46
Heel down/toe down t=.22 t=3.64 t=3.47 t=2.13 t=2.76 t=2.67

Conclusion: This study showed that there is a significant difference in certain joint angles on different running surfaces. The wrist showed no significant difference. The elbow showed significant difference in the toe off and heel down phase. The shoulder and the hip showed significant difference in every phase except mid-stance. And the ankle and knee showed significant difference in all four phases of the Gait. In conclusion, surfaces significantly alter the human Gait.