Analysis | Compound Exercises | Sports Conditioning
Qualitative Torque Analysis
A simplified qualitative method can be used to determine relative torque forces. As an example we can compare the relative torque forces through the hip, knee, and ankle joints. First, take a photograph of barbell squat in a full descent with a perspective perpendicular to joints plane. Draw a line of force through resistance on its center of gravity, straight up and down, parallel to force of gravity. Gravity acting on both body mass and added mass (barbell) contribute to resistance. Incidentally, compression forces act upon joints during squat stance. On the barbell squat, center of gravity is over instep (between forefoot and heel). If it is not, individual will fall over, toward the center of gravity.
Now, draw three separate horizontal lines, perpendicular to line of force from each joint articulation (ankle, knee, and hip) to line force. If image is not exactly viewed from the side, "horizontal" lines can be drawn in perspective to picture as shown. Once diagram is complete, a relative comparison can be made on the torque forces of the hip, knee, and ankle.
- Line of gravity positioned over instep
- Three joint torques are created from this line of gravity
- Feet push down into floor
- creates a vertical reactive force moving body and weight upward
- Examples
- Olympic-style front squat (diagram 1 above)
- Barbell positioned infront of body
- Torso more upright
- Relatively high knee torque (at bottom position)
- Bodybuilding-style squat (diagram 2 above)
- Barbell positioned high on shoulders
- Torso moderately sloped
- Torques more moderately distributed between knee and hip
- Powerlifting-style squat
- Barbell positioned low behind shoulders
- Torso highly sloped
- Relatively high hip torque
- Box Squat
- Participant sits back on box
- Very low knee torque
- Olympic-style front squat (diagram 1 above)
- Also see Squat Analysis
Other Compound Exercises
- Synergistic mechanics
- Greatest gross force production through true compound mechanics
- Exposes kinetics chain to particular forces necessary for adaptation
- Torque forces shifted toward target joints
- Emphasizes target muscle group or joint movement
- Decrease torque forces through venerable joint
- Too great a "torque shift"
- Decreases involvement of muscles involved through adjacent joint
- Basic exercise turns into auxiliary exercise
- Mechanics begin to resemble isolated exercises
- May decrease range of motion of both joints
- Examples
- Extra-wide grip bench press or Guillotine Bench Press
- Leg Press with feet very high on platform
- Subtle torque shifts (if any) may be more beneficial than more drastic torque shifts
- since greater weights can be used, thereby increasing overall strength performance.
Sports Conditioning
- Exercises should mimic biomechanics practiced in activity
- Coaches prescribe the powerlifting squat (wide stance, bar low on back, little knee torque)
- often excluding exercises with greater knee torque
- Rationale is Glutes are stonger than Quads
- So should we ignore Quad strength?
- See Squat Analysis
- Also see
