Muscle Mechanics Supplementary Information

These flashcards cover key vocabulary and concepts related to muscle mechanics, fascicle arrangements, muscle groups, and mechanical advantage in the musculoskeletal system.

Circular Fascicle Arrangement

Fascicles arranged in concentric rings, for example, orbicularis oris.

Convergent Fascicle Arrangement

Broad origin with fascicles converging toward a single tendon insertion, for example, pectoralis major.

Parallel Fascicle Arrangement

Fascicles parallel to the long axis of a straplike muscle, for example, sartorius.

Fusiform Fascicle Arrangement

Spindle-shaped muscles with parallel fibers, for example, biceps brachii.

Pennate Fascicle Arrangement

Short fascicles attach obliquely to a central tendon running the length of the muscle, for example, rectus femoris.

Unipennate

Fascicles attach only to one side of a tendon, for example, extensor digitorum longus.

Bipennate

Fascicles insert from opposite sides of the tendon, for example, rectus femoris.

Multipennate

Fascicles appear as feathers inserting into one tendon, for example, deltoid.

Rotator Cuff Muscle Group

A group comprising supraspinatus, infraspinatus, teres minor, and subscapularis that stabilizes the glenohumeral joint.

Rectus Abdominis

Muscle responsible for trunk flexion, commonly referred to as the 'sit-up' muscle.

Erector Spinae

Muscle group consisting of iliocostalis, longissimus, and spinalis, which are primary extensors of the vertebral column.

Quadriceps Muscle Group

Group including rectus femoris and vastus muscles, primarily responsible for knee extension.

Hamstring Muscle Group

Group including biceps femoris, semitendinosus, and semimembranosus, primarily responsible for knee flexion.

Hip Adductor Group

Includes muscles such as adductor longus, brevis, magnus, and others that are primarily responsible for thigh adduction.

Triceps Surae

Muscle group comprising gastrocnemius, soleus, and plantaris, responsible for plantarflexion of the foot.

Levers in the Musculoskeletal System

Rigid bars (bones) that move on a fulcrum (joint) when acted on by a force (muscle contraction).

Mechanical Advantage

Occurs when a load is close to the fulcrum, allowing a small effort to move a large load.

Mechanical Disadvantage

Occurs when a load is farther from the fulcrum, requiring more effort but allowing for greater speed and range of motion.