Status Updates From The Physics of Resistance E...

“A longer lever magnifies the load more and a shorter lever magnifies the load less.@

“Bent arm lateral raise can injury rotator cuff muscles.”

“When a secondary lever tilts away from the pivot of the primary lever, it increases magnification of the primary lever. When a secondary lever tilts toward the pivot of the primary lever, it reduces the magnification of the primary lever. The secondary lever is either lengthening or shortening the effective length of the primary lever.@

“The biceps engages when the forearm tilts outward and increases the load to the pectorals.”

“…the bicep engages when the forearm tilts outward and increases the lid to the pectorals.”

“The higher the percentage of active a lever is, the greater the percentage of available resistance that will be loaded onto the muscle that operates the lever.@

“Parallel bar dips require use of 4.5x MORE resistance than when he is doing supine dumbbell triceps extension. He is loading his triceps with less than HALF as much load (119 lbs) as compared to supine dumbbell triceps extension (240lbs).

“A lever that is perfectly perpendicular with the direction of resistance is fully active. It is at its heaviest at that position…”

Suspension/TRX hamstring curls are dangerous

“When the knee is bent at 90 deg, the hamstring is able to pull perpendicularly on the lower leg, which would entail a mechanical advantage. When the knee is straight, the hamstring is only able to pull on the lower leg from an angle that is almost parallel to the lower leg, which is a mechanical disadvantage.”

“Physique development training is most productive when using a resistance level that allows more than four repetitions, and as many as 20-30 repetitions.”

Muscles that always operate with a mechanical disadvantage: deltoids(anterior, lateral, posterior), erector spinae, gluteus, quadriceps, triceps.

Flexion muscles that experience a mechanical disadvantage at the early stage of their Range of Motion and then a mechanical advantage in the latter phases of their range of motion: biceps brachii, hamstrings, hip flexors, latissimus dorsi (lateral humeral flexion), pectoralis major