| How to gain leverage in your training. Would it be | | | | performed by the abdominals. The ball permits an |
| possible to train with the same amount of weight | | | | increase in range of motion by allowing you to |
| and make an exercise harder by manipulating the | | | | stretch back over the ball in hyperextension, which |
| lever systems of the body? Is it possible to make an | | | | forces your abdominals to lengthen and results in |
| exercise safer and lighter, but still attain the same | | | | more work when the muscles are shortening, while |
| benefits? If weight or load remains the same, then | | | | returning forward during the upward movement of |
| speed, distance and placement of the load are going | | | | the "crunch". To further increase the resistance |
| to be the variables. An increase in speed of an | | | | force, extend your arms behind your head which |
| exercise with load can definitely increase the danger | | | | again increases the resistance arm and therefore |
| to the joint. A decrease in speed will be safer on the | | | | makes it more challenging. You'll feel your abdominals |
| joint, but it sure can get boring. | | | | like you've never felt them before! |
| Manipulating the levers can be the best choice, the | | | | For chest, try the plate-loaded Cybex bench press or |
| most fun and the safest on the joint. First let's | | | | incline press. Before you put your weight on the bar, |
| review some basic concepts of biomechanics. A | | | | add two - four 2.5 lb plates on each side. Why? OK I'll |
| "parallel force" system is two or more parallel forces | | | | tell you. Remember, when performing a bench press |
| acting on the same object, but at some distance | | | | your chest wants to pull your arm towards the |
| from each other. To better understand this concept, | | | | midline of your body. Because these Cybex machines |
| we first must examine the principles of a lever | | | | move in an arc, the weight you're lifting ends up |
| system. Here are some examples: | | | | actually almost balanced over the shoulder joint, |
| There are three types of levers in mechanics: a first | | | | offering the chest very little resistance when you get |
| class lever is when the axis is in the middle of two | | | | to the top of the motion. Since this is where the |
| forces like a seesaw. A second class lever is when | | | | most "shortening " of the muscle occurs, this is |
| the resistance is between the axis of rotation and | | | | where you'd really want the chest to be challenged. |
| the effort force, similar to a wheelbarrow, and a third | | | | Be moving the load outwards on the bar with the |
| class lever is when the effort force lies between the | | | | two- four 2.5 lb plates you will have increased the |
| axis of rotation and the resistance, like a shovel. | | | | resistance arm keeping more tension on the chest |
| Remember, a lever is not unlike the handle on a | | | | and not on the joint through the whole range of |
| shovel or the handle of a frying pan. In the body, the | | | | motion! Cool huh? |
| long bones generally act as levers or rigid bars that | | | | Unwanted Stress to the joint. Anytime we lift a |
| rotate around an axis. The term "lever arm" is | | | | weight we impose certain stresses or forces on the |
| defined as the perpendicular distance from the axis | | | | joints of our body. Some of these forces are |
| of rotation to the line of force applied to the lever. | | | | impossible to eliminate, however minimizing the |
| The "resistance arm" is a term referring to the lever | | | | excessive forces will definitely keep your joints "in |
| arm of the resistance force while the "effort arm" is | | | | business" for the long haul. With this in mind, let's |
| a term that refers to the lever arm of the effort | | | | review some more physics. |
| force. | | | | Newton's "third law of reaction" states: "For every |
| Got that? If you were holding a frying pan, with your | | | | action there is an equal and opposite reaction." |
| wrist in a neutral position, the resistance arm would | | | | Therefore, when two surfaces make contact with |
| be the distance from your wrist to the end of the | | | | each other, there is perpendicular force or "contact |
| frying pan, while the effort arm would be the | | | | force" like a bat hitting a ball, or a parallel force |
| distance from your wrist back to your elbow. If you | | | | referred to as a "shear force" akin to rubbing both |
| were flipping your eggs , the axis of rotation would | | | | hands together. When adding load or weight, |
| be your wrist. This will start to make sense when we | | | | excessive stress or forces can occur inside the joint |
| apply it later to exercises. | | | | and, in time, possibly lead to degeneration of the |
| One example of a second class lever system would | | | | joint. Here's how to lower the unnecessary shear |
| be a standing calf raise: The weight is on your | | | | forces while exercising: |
| shoulders, the axis of rotation is at the MTP or | | | | Anytime you can move a weight or the resistance |
| metatarsophalangeal joint, (where the axis is when | | | | closer to the joint the better. Not only will you be |
| you stand on the tip of your toes) and the weight or | | | | able to use a heavier weight, but the shearing forces |
| resistance force ( gravity acting on both the weight | | | | to the joint will be less. For example, while performing |
| plus the weight of the body) is acting on the | | | | hip extension, abduction or adduction with an ankle |
| forefoot behind the axis at the MTP joint. The calf | | | | cuff, move the cuff up above the knee . This will |
| muscles or the "triceps-surae" actively contract and | | | | protect your knee joint and lower the shear force in |
| plantarflex the ankle to lift the body off the ground. | | | | your hip. For another option, use the multi-hip machine |
| This is a second class lever which is very rare in the | | | | with the pad just above the knee. As long as the |
| human body. Remember the wheelbarrow. | | | | axis of the machine is aligned with the moving hip |
| The only problem is compression from the weight on | | | | you'll be fine. |
| the shoulders through the spine. What if we were to | | | | When performing lateral raises, flies or stiff arm |
| use a CYBEX rotary calf machine instead, which is a | | | | pulldowns for lats, try moving the weight to your |
| seated joint axis machine? Now, instead of standing, | | | | elbow. This will be easier on your elbow and lower |
| the weight is off your spine and the axis of rotation | | | | the shear forces in your shoulder. For lateral raises, |
| has now moved back to the ankle. The load is now | | | | you might have to find an ankle cuff that will fit |
| centered on the MTP joint, in front of the axis and | | | | around your arm. Try to use a cable instead of a |
| the calf of course, has no choice but to remain in the | | | | dumbbell, or as Tom Purvis taught me, simply hold |
| same spot. This is a first class lever or a seesaw. | | | | the dumbbell in the crook of your arm, where your |
| You can generally lift more with a wheelbarrow than | | | | elbow bends. |
| a seesaw, but will the calf work any less because of | | | | For flys, the cable and ankle cuff work great, |
| the decreased mechanical advantage? Actually, | | | | particularly with an incline bench. Remember to slide |
| because of the decreased mechanical advantage, the | | | | the cuff above your elbow. You might however, |
| calf might even work harder! | | | | need someone to help attach the cable to each ankle |
| The speed remained the same, the load became | | | | cuff. |
| actually lighter (which is better for the joint) and the | | | | To perform straight arm pulldowns with a cuff, you'll |
| calf is still working hard. As an extra bonus, you have | | | | need a longer strap that allows your arms to spread |
| rid yourself of the spinal compression from the | | | | wide enough to slide past your body |
| weight on the shoulders. | | | | For knee extensions, move the pad higher on the |
| If you have to perform a standing calf raise, try it on | | | | shin close to the knee. In physical therapy clinics I've |
| a Hammer shrug machine where the weight is | | | | seen an attachment used on ACL patients that |
| grasped in the hands. The limiting factor will be the | | | | straps to the lower leg, transferring the load or |
| amount of weight you can hold, which can be | | | | resistance force up closer to the knee. This will |
| remedied with straps. For people with back pain, this | | | | considerably reduce the amount of shear force |
| could be a viable option. | | | | across the Patellofemoral joint. Remember, your knee |
| For biceps brachii, a dumbbell curl works great. How | | | | is a hinge joint -- it only moves up and down. Be sure |
| can you make it harder without increasing the weight | | | | the axis of the machine is lined up correctly with the |
| or speed? | | | | knee. There is no exception to the position of your |
| There are three muscles that help flex the elbow. | | | | knee and the axis. |
| The brachialis, the brachioradialis and the biceps | | | | If you want an alternative exercise for leg |
| brachii. The brachialis works hard regardless of hand | | | | extensions for people with no anterior cruciate |
| position, but to emphasize the biceps brachii, you | | | | ligament (ACL) and remove all the unwanted shear |
| must supinate. Why? Both heads of the biceps brachii | | | | forces, try a "terminal knee extension". This exercise |
| are attached to the radius which makes them a | | | | was shown to me by a physical therapist named |
| powerful supinator. Supination is when your hands | | | | Michael Jones. I adapted it to a multi-hip machine. |
| hang at your side with palms facing forward. Recall | | | | Stand on the platform of a multi-hip machine and |
| from your anatomy, the radius is the bone in your | | | | place the pad at a 45' angle. Place the pad behind the |
| forearm that crosses over the ulna to cause | | | | kneecap in the popletial fossa. There is not much hip |
| supination. | | | | motion so you don't have to align the hip to the axis |
| To increase tension on the biceps without increasing | | | | of the machine. Adjust the weight to the appropriate |
| the weight, try something a little different. Instead of | | | | resistance and just extend the leg against the |
| grasping the handle in the middle of the dumbbell, | | | | resistance at the pad. This will eliminate most of the |
| move your hands toward the outer end of the | | | | unnecessary shear forces and allow the knee to |
| handle closer to the outside weight away from your | | | | work in its basic naturally engineered function. I love |
| body. Realize this will cause your hand to rotate or | | | | it! |
| "pronate" toward the body. That's OK, in fact that's | | | | I hope this will provide you with a few ideas on how |
| the whole idea. You are actually increasing the length | | | | to train harder as well as smarter. These techniques |
| of the resistance arm (for supination), forcing your | | | | will not only improve your workouts in the short |
| biceps to work even harder as a supinator, resulting | | | | term, but might maintain the integrity of your joints, |
| in more "work" by the biceps with the same amount | | | | keeping you healthier for the long term, preventing |
| of weight! | | | | you from injury and keeping you fit. |
| For abdominals, try a Swiss ball. Normally, when you | | | | References: |
| perform a crunch, the ribs move toward the pelvis | | | | 1. Baechle, R. Thomas. Essetnials of Strength Training |
| and the lower back or lumbar spine will naturally | | | | and Conditioning. 3:25-27 |
| flatten against the floor. In actuality, there is not a lot | | | | 2. Franks B. Don and Howley T. Edward. Health and |
| of "work" done until the back actually flattens against | | | | Fitness Instructor's Handbook. 5:86-87 |
| the floor. Your ribs aren't rising up from the floor as | | | | 3. Hamill, Joseph and Knutzen, M. Kathleen. |
| much as your back is moving downward with the | | | | Biomechanical Basis of Human Movement 10:397 |
| help of gravity. Instead of a crunch on the floor or | | | | 4. Jones, Michael. PERC Post-Rehab Protocols. |
| bench, lie back on the Swiss ball. Don't worry, | | | | Anterior Cruciate Ligament Protocols 1:5 5. |
| hyperextension of the thoracic spine (upper back) is | | | | 5. Norkin, C. Cynthia and Levangie, K. Pamela. Joint |
| natural. The ball is round, so it will contour to the | | | | Structure and Function 1:32-35, 1:52, 2:82 |
| curvature of your lower spine and offer extra | | | | 6. Purvis, Tom. |
| support while increasing the amount of "work" | | | | |