Joint Mechanics & Types
This category of joint is slightly movable under normal, healthy conditions.
amphiarthroses
The standardized adult human skeleton contains this many total bones.
206
The root and suffix of the word "kinesiology" literally translate to this phrase.
the study of movement
In coordinate movement pairing, the primary muscle producing a dynamic motion in a single directional path is designated as this.
agonist (or prime mover)
Peripheral nerve impulses transition from one neuron to another target cell across this microscopic gap.
synapse
This classic hinge joint is biomechanically restricted to permitting only uniaxial flexion and extension.
elbow
This bone is the most frequently fractured bone across the entire human appendicular skeletal framework.
clavicle
A severe macro-tear of a bone-to-bone ligament is explicitly classified as this injury, distinct from a muscle or tendon strain.
sprain
This core functional property represents a muscle cell's ability to return to its original resting length post-contraction.
elasticity
In a myelinated alpha motor neuron, electrical commands can travel at a maximum velocity of this many miles per hour.
268 miles per hour
The human skeleton contains only one classic saddle joint, which is located uniquely in this anatomical structure.
the base of the thumb
While the human wrist contains 8 carpals, the structural foundation of the human ankle contains this many tarsal bones.
7
Primary fibrositis localized explicitly within the lower back is clinically and colloquially referred to by this term.
lumbago
An explosive powerlifter heavily utilizes this specific type of muscle fiber that operates via oxygen-free pathways.
Type II fast-twitch fibers
Depolarization of a neural action potential occurs when this specific ion floods inward, switching the cell's charge to positive.
Sodium
These fibrocartilage structures between spine vertebrae absorb crushing functional loads and allow tiny, controlled shifting movements.
intervertebral disks
These large, bone-destroying cells secrete powerful enzymes to dissolve organic matrix for remodeling and calcium release.
osteoclasts
This metabolic joint disorder is characterized by a painful accumulation of uric acid crystals within joint spaces, typically attacking the big toe.
gout
Skeletal muscle architecture includes this specific sheath that wraps around each individual muscle cell.
endomysium
"Triad of Nerve Trauma" categorizes trauma into laceration, traction, and this third distinct mechanism.
compression
The "Law of Joints" states that there is a functional trade-off between stability and this other competing structural duty.
mobility (or range of motion)
The adult hip bone (Os Coxae) is integrated from the superior ilium, the anterior pubis, and the posterior skeletal segment.
ischium
In this type of exercise, the distal end of the limb remains fixed to an immovable surface, recruiting multiple joints simultaneously.
Closed Kinematic Chain exercise
Under microscopic analysis, cardiac muscle is uniquely identified by its branching layout and the presence of these fast-communicating structures.
intercalated discs
When a severed peripheral nerve axon has an intact myelin sheath framework, it can regrow at this approximate slow crawl rate.
1 millimeter per day (or ~1 inch per month)