Biomechanics


Amplitude Of Movement, Law of Repetitive Motion, and Plyometrics

You may have heard trainers and coaches talk about movement amplitude. I often talk about amplitude as being one of those performance characteristics that determine the outcome of a training regimen and one of the factors indicating reductions or improvement in performance.

Amplitude is also part of the "law of repetitive motion" equation developed by Dr. Michael P. Leahy, who is the founder of Active Release Techniques (ART). This "law" is an equation describing the interaction between various parameters of human motion: I=NF/AR where:

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Biomechanics, Injury Prevention, and Performance: Training to Fail Pt. 6

The last post about the concept of optimal strength training was more philosophical than practical. Even so, many practical ideas are derived from an underlying philosophy concerning training. Nevertheless, I promised to get more technical and “sciency” in the next post so this one is about science itself being applied to strength training.

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The Shoulder Complex: Demystifying the Shoulder with Eric Beard

The shoulder joint itself is known as the glenohumeral joint. It is a multi-axial ball and socket enarthrodial joint. This joint is the articulation between the glenoid fossa of the scapula and the head of the humerus. This is the area that most people think of as the shoulder joint. The humerus is, however, one bone of the shoulder.

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Ideal Postural Alignment (Normal Posture)

In this postural alignment the neck is slightly extended, the upper back is in slight flexion, and the lower back is in slight extension.

What follows is a brief over-view of normal or "ideal" postural alignment. It should not be considered to encompass all the structural variations that can exist, but may still be considered normal and having not arisen from aquired postural distortions.

The slightly extended inward curve of the neck (cervical spine) and lower back (lumbar spine) is referred to as lordotic.

In this way a normal slightly arched position of the neck and lumbar in a position of lordosis.

However, this term is generally meant to mean a hyper-extended or over-arched position.


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Wobble Boards, Bosu Balls, or Foam: What's The Difference?

You've probably seen a wobble board before. They are these round discs with a ball or disc underneath them. Bosu balls are similar but they are more like a half swiss ball with a platform attached. Figure 3 below shows a boy jumping from bosu ball to bosu ball using the "ball" side. These can also be turned over on a hard surface so that the ball is a pivot. People use this method for pushups, for instance.

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Romanian Versus Stiff Legged Deadlifts

These two exercises, stiff legged deads and Romanian deads, I think have sort of been wrapped around each other in myth and shadows.

Everybody seems to have a different take.

Not to mention that some people teach the conventional deadlift based on its difference from these other two. So you get this kind of thing like "conventional deadlifts are more like a squat than the stiff or Romanians".

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