Our bodies were designed thousands of years ago before the computer, the car and any type of resistance or cardiovascular equipment. Whenever I look at an exercise I try not to be affected by dogma. Exercise is simply resistance applied to the musculo-skeletal system. Whether it's Yoga, Pilates, Boxing, body-building, Spinning or whatever, it's always prudent to evaluate the risk or benefit of an exercise based on joint structure, function and how and where the resistance is applied to all the joints affected by an exercise.
Muscles are slaves to joints. If you were to lose your biceps, or they were was removed, you would still be able to bend your arm because, there are two other muscles, the brachialis and the brachioradialis that can bend your arm. However, if you were to smash your elbow, it wouldn't matter how many muscles or pulleys you had crossing the elbow. You still wouldn't be able to move it. Muscles are well equipped to regenerate, while joints, especially synovial joints, are more likely to degenerate. It's called arthritis.
Resistance training might seem evasive but it's really invasive. Any resistance applied to the body affects the joint surfaces inside the body which you can't see or might not even feel at first. Remember, gravity and the weight of your body can also be resistance.
If you're training for a sport, then in most instances winning the game is more important than keeping you body intact. Let's face it, sports are not healthy. Flying down a mountain at 60-70mph in lycra or running as fast as you can into someone twice your size are not the healthiest things to do. Skiing and football are sports. In the weight room, we're supposed to be strengthening our bodies to withstand the abuse we subject them to in our daily lives or when playing sports. Think long term. How will these exercisers affect you in the long term after repeating these motions over and over, year after year. Are they natural motions? Is the resistance applied through the joint or across it?
With that said, below you will find some common mistakes people make in regards to exercise in the gym.
Lateral flexion on a 45 degree hyper-extension bench.
The knee is primarily a hinge joint with 1degree of freedom. It is not designed to have a force or "load" crossing the hinge. If every time you opened your car door you leaned on the door pushing it towards the ground, it wouldn't take long for your hinge to wear out. Without realizing it, that's exactly what occurs when performing this exercise. If your feet are locked in with a force pushing one way and your hips are locked in with a force pushing in the opposite direction, the knee is affected in the middle. (see photo below) Performing this exercise might not hurt you today but keep doing it for 10 years and your MCL or LCL might have been stretched making your knee unstable.
The sad part is most people are performing this exercise in order to make their waist smaller. In reality, a muscle won't get smaller when you work it. It will get stronger and tighter but it won't shrink. This exercise works the obliques, quadratus lumborum and spinal erectors on one side. Below are a few options that wouldn't sacrifice the knee and still accomplish the same goal. Keep in mind the obliques are designed to rotate you. They are large fan shaped muscles. Resist rotation and your obliques will work big time.
Leg extension in internal or external rotation.
Some of the equipment in the gym are "joint axis" machines. They were designed to align themselves with the joint that is moving. The leg extension and the leg curl are examples of these machines. There is usually a small dot or circle to align your knee with. It is imperative that the knee is aligned with the axis of the machine for the same reasons as above. The knee only bends one way. When your leg is in full extension, the center of the knee cap (the patella) should be pointing towards the ceiling. Don't worry about what your feet are doing. They aren't being resisted, the knee is. Think joints not muscles. The knee is moving, so the muscles crossing the knee have to be involved. Do not rotate your leg inward or outward because it affects the way the resistance crosses the knee. You don't want to wear out your knee to work your quads or hamstrings. Without the knee, your quads and hamstrings become useless at the knee.
You might want to dorsiflex the foot (pull your toes towards your tibia) in both of these exercises. It's more natural to dorsiflex when performing a leg extension because it mimics gait patterns. Dorsiflexion also puts a stretch on the gastrocnemius in the leg curl. Because the gastroc is a two joint muscle and crosses the knee it can assist in a leg curl when you dorsiflex the foot.
VKR (Vertical Knee Raise) or Dips
The shoulder is the most mobile joint of the body. It is held in place entirely by soft tissue. The only bony attachment for the shoulder girdle is the sterno-clavicular joint. The wrist is no slouch either. Both of these joints are primarily affected when performing dips. Only the shoulder is at risk with the VKR. Stabilize the shoulders and the wrist. Don't let your shoulders hike up towards your ears. No use hurting your shoulder to work your hip flexors in a leg raise.
A joint capsule is similar to the plastic surrounding a 6-pack of soda. Once you stretch it, it doesn't come back.
Never put weight on your thighs with your heels on a bench and your hands on another bench to perform a dip. The knee, especially the ACL (anterior cruciate ligament) won't like it at all. The knee is considered the most complex joint of the body because it just a ledge sitting on top of another ledge. (See the photo below.) The ACL prevents anterior or forward translation of the femur on the tibia. Setting weights on your thighs is like contributing to an orthopedic surgeons BMW fund!
Tricep push-down
The wrist is at risk here. Keep the wrist in neutral. Don't bend your wrist backwards too far into hyper-extension. It puts too much stress on the carpal tunnel.
Chest press
The joints at risk are the shoulder and the wrist. Although the elbow is also moving you shouldn't have a problem with the elbow unless you hyper-extend it with a lot of weight.
When bench pressing or performing a chest press, try to keep the humerus in line with your trunk. The humerus can extend back further than your trunk, but not much. Again, you don't need to put too much stress on the shoulder joint. Don't worry about whether the bar is touching your chest or not. That only matters in power-lifting competitions. Don't even think about the "stretch-reflex" mechanism of the passive system. Unless you're a powerlifter, this exercise like all weight-lifting exercises, should be slow and controlled.
The range of motion for this exercise is determined by the width of your chest and the relationship between the chest-width and the length of your humerus, radius and ulna bones, which in turn affects the joints moving.
Multi-Hip
This is another joint-axis machine. The hip is supposed to align itself with the axis in the center of the swing arm. If not, you'll be applying excessive force to the joint surfaces which are the head of the femur and the socket or acetabulum (the hip joint). Remember, it's the moving joint that must be aligned with the axis. If you're performing adduction, abduction or hip flexion you must align the moving hip with the axis of the machine. Just lift the platform so it aligns the axis.
I hope this helps you to long term health. Common sense goes a long way. Keep it simple and change your exercises about every two to three months. It's like rotating your tires.
Disclaimer: All information on this site is provided for informational purposes only! By no means is any
information presented herein intended to substitute for the advice provided to you by any health care or other professional
or organization.
