Qualitative Biomechanical Analysis: Injury Development

Vocabulary practice flashcards covering mechanical stress types, tissue adaptation zones, the stress continuum, overuse vs. traumatic injuries, and injury prevention strategies from Chapter 15.

what are forces acting on body responsible for

all motion and injury

Mechanical Stress

The distribution of a force over the body it acts on.

types of mechanical stress

include tensile, compressive, and shear stresses.

Compressive Stress

forces squeezing the body

Tensile Stress

forces pulling or the body

Shear Stress

forces that tend to slide two parts of a body across each other.

Complex Loading

combination of compressive, tensile, and shear stresses

what do biological tissue adapt to

the level of stress imposed on it

Hypertrophy

adapts to higher stress by increasing size

• tissue gains strength

• bone minerlaiztiojn increases, tendons and ligaments resit tension

Atrophy

adapts to lower stress by decreasing size

• tissue loses strength

• bone demineralizes, tendons and ligaments lose flexibility

Stress Continuum

A spectrum representing the full range of imposed mechanical stresses on biological tissues, progressing from low stress (underload) through maintenance and training to high stress (overload).

Physiologic Loading Zone

level of stress the tissue is currently adapted,

• maintenance level of stress (eustress).

Physiologic Training Zone

level of stress greater than what the tissue is currently adapted

• causes tissue microdamage that stimulates beneficial tissue remodeling

Overload Principle

The principle of systematically imposing loads above a tissue's yield threshold while

• providing adequate rest time for beneficial remodeling to take place.

Pathologic Underload Zone

prolonged exposure to stress levels below current tissue adaptation,

• detraining effect, tissue weakening, bone demineralization, and muscle wasting (e.g.,

• sedentary lifestyle, immobilization, or space flight).

Pathologic Overload Zone

high levels of stress that cause substantial tissue damage to tissue

• leading to traumatic or overuse injury.

Traumatic Injury

single application of a high level of stress, such as a ligament tear, bone fracture, muscle avulsion

Overuse Injury

repeated applications of low-level stress

Williams' Model for Overuse Injuries

A biomechanical framework describing how increased training effort increases tissue stress and microdamage, leading to stronger tissue if remodeling exceeds damage, or an overuse injury if damage outpaces remodeling.

what does an overuse injury reflect

the number of repetitions and the stress magnitude

what does higher magnitude of imposed stress do

allows for fewer repetions for injury

why is adequate rest for remodeling critical

without recovery time, stress re-imposed on still-damaged tissue

Tissue Stress Threshold Hierarchy

The comparative order of stress thresholds across biological tissues: $\text{bone} > \text{tendon} > \text{ligament} > \text{cartilage}$.

Bone Directional Stress Tolerance

The directional variation in bone's ability to resist mechanical stress, ordered from strongest to weakest: $\text{compression} > \text{tension} > \text{shear}$.

Tendon and Ligament Directional Stress Tolerance

($\text{tension} > \text{shear}$).

do thresholds differ among people

yes

how do threshold differ among ppl

genetics, training, neutrino, previous tissue adaptations

what is another thing that differs among tissues and individuals

time for remodel

Intrinsic Risk Factors

factors related to the individual

• determine individual ability to withstand loading

Extrinsic Risk Factors

factors related to the task and environment

• characteristics of the imposed loading: task being performed, environment in which taks is performed

what do intrinsic factors set

threshold value for the level stress that may cause injury

what do extrinsic factors reflect

the potential for a given performance to impose a stress exceeding threshold value

what reflects intercalation of both intrinsic and extrinsic facts

risk of injury to an individual performing a particular task

Cross-Training

A training program with day-to-day rotations among a variety of activities ex. running, cycling, swimming , dancing

what does each activity of cv do

• impose a different pattern of loading on different tissues

• provides time for remodeling

• avoids cumulative effect of repetive loading

Within-Activity Cross-Training

alter performance parameters while performing the same physical activity to avoid cumulative loading

how to avoid risk of injury during performance of a task

• consider anthropometrics when selecting skill , posture affects pattern of loading on the body

• select appropiate trainign equiepemt and location

• include ct and within activity ct: alter the pattern of loading regularly imposed on the body

• set reasonable imporvement goals, avoid too much too soon , reasonable increases in frequency, duration, intensity

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