STANDARD
The Trunk Extension is the seventh exercise in the Strength Training Machine drill.
This exercise develops strength in the low back muscles and supports the Deadlift exercise.
Figure 15-13 shows the exercise as a Soldier conducts it:
Starting Position
The starting position for the Trunk Extension is the Sitting position with the knees slightly bent and feet flat on the foot platform.
From the starting position, stay seated on the machine, leaning slightly forward, with the back firmly against the padded lever arm.
Select the appropriate weight and ensure the pin is secure in the weight stack.
Grip the support bars using a neutral, closed grip.
Keep the head in a neutral position with the eyes looking straight ahead.
Count
● On count 1, raise the upper body and continue extending the trunk, moving to the Supine position.
● On count 2, return to the starting position.
Repetitions
Repeat this movement for the correct number of repetitions and sets required to meet the goal of the strength machine session.
MODIFIED TRUNK EXTENSION
The modified Trunk Extension should be used when a DA Form 3349 may limit the range of motion at which a Soldier can safely perform Trunk Extension exercises.
The weight load should be low and the range of motion of the movements should be within the comfort zone of the Soldier.
Gradually increase the weight load and range of motion as tolerated until the exercise can be performed to standard.