The Science of Biomechanics
1. Understanding movement is critical to making your strength and conditioning program efficient and effective.
2. How do we go about this? How do we interpret movement and understand biomechanics in a practical and applicable way for everyday training?
3. Definition of Biomechanics – The science of human motion, which includes effects of internal and external forces on the human body.
4 . It must be applied with other sciences of the body, as well such as energy systems and neurophysiology.
o Ex. More efficient movement means using less energy to perform a task.
We can simplify biomechanics by thinking of three movement constants
1. Body – Lever (bones) and motors (muscles) that produce and reduce force.
2. Ground – This is where we derive force. "Ground Reaction Force." What happens to the knee and hip joints when the foot hits the ground?
3. Gravity – This serves to load the system. Being aware of center of gravity is critical to movement. A person needs to learn how to stabilize as the center of gravity changes.
Understanding Movement
1. Most important – The body is a linkage system- there is a sequence and timing of body segments during movement. There needs to be neuromuscular synchronization for efficient movements.
2. Because the body is a linkage system, movement errors can be traced to a cause and effect relationship
o Ex. Pitchers with contra-lateral hamstring tightness may develop a shoulder tendonitis in the pitching shoulder. This is due to the opposite side lower extremity not being able to reduce force on the follow through, so the shoulder joint takes an abnormal amount of trauma.
o Ex. If the ankle becomes less mobile due to an ankle injury or leg asymmetry, then more than likely, the hip will become tight from not being able to go through normal motion as well.
3. It is easier to think of movement in terms of planes of motion. TRAIN MOVEMENTS, NOT MUSCLES.
o Ex. Hip: Sagittal– flexion/extension (front to back movement)
Frontal – Abduction/Adduction (Side to side movement)
Transverse – External/Internal Rotation ("ER/IR")
- This may happen in a joint or globally with the whole body.
4. The system works by loading a muscle then unloading a muscle. This is how the body reduces and produces force.
o Shock absorption=reaction=force reduction=loading=eccentric=pronation
o Propulsion=action=force production=unloading=concentric=supination
5. The body wants to work in a cyclical manner.
o Ex. Walking gait can be used as a functional model for analysis. What happens to the foot, ankle, knee, hip, lumbar spine, shoulder girdle and arms?
6. Think in terms of pattern movement.
o Why? Neurologically the brain does not recognize individual muscle, rather it recognizes patterns of movement in response to sensory input (proprioception).
o Try to get people to do things unconsciously. Cueing with a reach or a touch is a very valuable tool for functional training.
o Ex: Getting someone to reach the opposite arm across the body while doing a lunge or balance drill will facilitate interal rotation at the hip without consciously thinking about it. This subconsciously lengthens the powerful glut muscle in essence “turning them on” or loading the system (gluts).
General Information & Tips:
1. Categorization of movement patterns may simplify things as well.
a. Rotating
b. Bending
c. Extending
d. Pushing
e. Reaching
f. Pulling
2. This train of thought tells us to emphasize multi-joint movements in strength training rather than isolation.
3. Practical Example: It is common to see pitchers and quarterbacks throwing from their knees or performing traditional rotator cuffs bands exercises to improve arm strength. This may be highly counterproductive creating wrong movement patterns and does not train correct neuromuscular pattern synchronization. This can also lead to compensation patterns which may lead to overuse injuries.
4. In rehab, traditionally the transverse plane has been neglected. From experience, I have learned transverse plane motions are easy for the client to perform and people reach their goals earlier.
5. Muscles of the core are orientated to take advantage of the powerful transverse plane. The body is able to best convert torque and forces in the transverse plane.
6. The trunk/core – One of the most complicated areas in the body to functionally understand. It consists of so many different core muscles…from the abdominal muscles to the back muscles to the hip muscles.
7. In function, the body unconsciously recognizes change in center of gravity, changes in velocity, change of forces in relationship to gravity. In training, we must introduce a person to a safe, yet unstable environment in order for the body to learn how to adapt and cope with changes in real life activities.
8. On a whole, I believe frontal plane strength especially in relationship to gravity is highly neglected. Very rarely have I seen a patient in the clinic or an athlete in the high school with good functional frontal plane control within the trunk and hips. What does this tell me? Strengthening clients in frontal plane may go a long way to prevent injuries the future. Doing exercises on your side (side lying hip abduction) or using a hip abduction machine does not translate to increases in strength or performance increases in functional settings.
HIPS ARE CRITICAL
1. I believe normal hip motion with strength to control that motion against forces and gravity is vital to increasing performance. The butt/hips is the powerhouse for all movement and loose supple hips are key to being more explosive, quick and injury free!!!!!!!!!!
2. As the hips lose motion due to pain, arthritis changes, and fatigue, it puts extra torque or stress on the back because the body needs to get the motion from somewhere else.
3. The hips allow the trunk, shoulders and the legs to be powerful and successful in all forms of function.
4. Whether I am dealing with a 70-year-old total knee patient, a 13-year-old high school athlete, or a person coming off ACL reconstruction, early on, I focus the majority of training on the hips.
Understanding the relationship between the shoulder and the hip is Key.
Tri-plane function of the shoulder – To load our shoulder in the transverse, frontal and sagittal planes, we let gravity, ground reaction and the momentum of our body load the muscles eccentrically (the scapula muscles, back muscles, hip muscles, posterior/anterior muscles eccentrically), so we can concentrically produce the force needed to get the job done (e.g. doing a bicep curl).
Internal Rotation ("IR")- Rotation toward the center of the body.
External Rotation ("ER")- Rotation away from the center of the body.
1. Hip internal rotation loads the same side arm and produces internal rotation in the shoulder in transverse plane.
2. Hip internal rotation loads opposite side arm and produces external rotation in the shoulder in transverse plane.
3. Hip flexion (flexing) leads to same side shoulder flexion in the sagittal plane.
4. Hip adduction (bring in toward body) loads opposite side shoulder and leads to shoulder abduction (draws the limb away from the body) in the frontal plane.
o Examples:
§ Tennis – back hand/forehand
§ Pitching – cocking phase/deceleration phase
§ Jumping to get a rebound
§ Spiking a volley ball