Question

Directions: For each of the following exercises write the type of contraction (concentric, eccentric, or isometric) occurring in each muscle group (quadriceps and hamstrings). If no contraction occurs, write “none.” In some instances you may have more than one type of contraction in the same muscle groups throughout various portions of the exercises. If so, list them in the order of occurrence.

Exercise	Quadriceps	Hamstrings
a. Lie prone with your knee in full extension.
1.) Maintain your knee in full extension.
2.)Slowly flex your knee maximally.
3.) Maintain your knee in full flexion.
4.)From the fully flexed position, extend your knee fully but stop immediately before reaching maximal extension.
5.) From the fully flexed position, slowly extend your knee fully.
b. Begin sitting on the edge of a table with your knee in full extension.
1.) Maintain your knee in full extension.
2.) Slowly flex your knee maximally.
3.) Maintain your knee in full flexion.
4.) Maintain your knee at approximately 90 degrees of flexion.
5.) From the fully flexed position, slowly extend your knee fully.
c. Stand on one leg and move the other knee as directed.

1.) Slowly flex your knee maximally.
2.) Maintain your knee in the fully flexed position.
3.) From the fully flexed position, slowly extend your knee fully.

Answer 1

a)Lie prone with your knee in full extension.

1) maintain your knee in full extention

• Quadriceps:- no action, gravity is pulling the tibia down.
• Hamstrings:- no action, due to the design of the joint hard end feel.

2)Slowly flex your knee maximally.

• Quadriceps:- 1st phase- no action, 2nd phase:- eccentric.
• Hamstrings:-1st phase- concentric, 2nd phase- no action.

3)Maintain your knee in full flexion.

• Quadriceps:- no action, approximation of soft tissue couteracts gravity.
• Hamstrings:- same as quadriceps.

4)From the fully flexed position, extend your knee fully but stop immediately before reaching maximal extension.

• Quadriceps:-1st phase- concentric, 2nd phase- no action
• Hamstrings:- 1st phase- no action, 2nd phase- eccentric.

5)From the fully flexed position, slowly extend your knee fully

• Quadriceps:- 1st phase- concentric, 2nd phade- no action, passively stretched by gravity.
• Hamstrings:- 1st phase- no action, 2nd phase- Eccentric.

b. Begin sitting on the edge of a table with your knee in full extension

1.) Maintain your knee in full extension.

• Quadriceps:- isometric
• Hamstrings:- no action

2.) Slowly flex your knee maximally.

• Quadriceps:- 1st phase- Eccentric. 2nd phase- no action.
• Hamstrings:- 1st phase- no action, 2nd phase- concentric.

3.) Maintain your knee in full flexion.

• Quadriceps:- no action
• Hamstrings:- isometric

4.) Maintain your knee at approximately 90 degrees of flexion.

• Quadriceps:- no action
• Hamstrings:- no action

5.) From the fully flexed position, slowly extend your knee fully.

• Quadriceps:- 1st phase- no action, 2nd phase- concentric.
• Hamstrings:- 1st phase- Eccentric, 2nd phase- no active.

c. Stand on one leg and move the other knee as directed.

3.) From the fully flexed position, slowly extend your knee fully.

• Quadriceps:- no action, gravity cause tibia to move.
• Hamstrings:- Eccentric.