Mechanical Wear Pattern

The material presented below is extracted from the Resistance Training Specialist course manual, written by Tom Purvis. Copyright of Focus on Fitness, OKC, OK.

Serious information for anyone serious about lifting weights. -Bill

Definition: Load displacement patterns on the articulating surfaces of joints.

When we think of weight training, we normally think about loading the muscles around a joint, at least we do until we get hurt. Joint surfaces endure tremendous loads during weight training. Freely moveable joints have articulating surfaces covered in hyaline cartilage. When this cartilage is compressed, fluid is squeezed out through pores in the surface layer. Ordinarily this is fine, and because the cartilage has no blood supply, it is the main mechanism for nutrient exchange. When loads are excessive, go on for too long, are repeated too often, or all three, several things are likely to happen.

A decrease in the permeability of the cartilage resulting in decreased nutrition and subsequent degenerative changes.
Fractured cartilage, which, if the damage is severe enough, the perichondrium will fill with dense scar tissue.
Asbestiform degeneration so named for the accumulation of thick aggregates of abnormal collagen.
Calcification of the matrix, (the stiff goo in which the collagen fibrils are embedded). Calcification of the matrix is by far the most common degenerative change, and is likely to be an accelerated eventuality following any of the scenarios above (1-3).

Very often we encounter these problems not just because of “big weights on the bar”, but because we handle those “big weights” or even the” not so big weights” with technique that actually converts the force generated by the muscles into compression and shear on the joint surfaces than it does torque.
Unfortunately, these problems are not either/or. Weight training should be one of the healthiest things that we ever do. Done intelligently, it provides our joints with the perfect balance of load and motion to help them resist the affects of an increasingly sedentary lifestyle, and slow the process of aging. Some of the degeneration is inevitable with age. Progressive resistance training can either slow the process down, or speed it up depending on how we go about it. Just say no to premature joint degeneration!

Mechanical strain on soft tissues can lead to serious injuries.
Wow, there’s a shocker! Virtually everyone who lifts weights consistently will get at least a minor strain at some point. A few concerns include:
Acute sprains of grade 1 or above usually due to uncontrolled momentum. (Grades are from 1-4. 4 being a complete separation from a bony attachment)
Chronic repetitive sprain/strain due to improper mechanics over time, inadequate recovery, inappropriate load or volume, or basically any mistake that we keep making.
Tendonitis, (inflammation of a tendon), Tensosynovitis, (inflammation of a tendon sheath).
Joint laxity due to accumulated damage to the ligaments and joint capsules, (a major predisposing factor toward future injury).

Aside from the odd low-grade muscle strain, most of these things can be avoided. Modern weight training technique, respect for progression, and common sense are our best weapons in the fight against injury.

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