42 Questions
Active movement is caused by gravitational pull.
False
Passive movement can be caused by stretched connective tissues.
True
Osteokinematics describes the motion of bones relative to two cardinal planes of the body.
False
Degrees of Freedom refers to the number of permitted, independent directions of angular motions allowed at a joint.
True
Greater degree of freedom at a joint indicates greater stability of that joint system.
False
All synovial joints in the body only allow angular movements, no translations.
False
Excessive translation of a bone relative to the joint always indicates normal joint health.
False
A significant reduction in translation within a joint may indicate pathologic stiffness.
True
If the agonist and the antagonist contract simultaneously, co-contraction occurs to provide stability for the joint.
True
A neutralizer muscle prevents unwanted motion at the joint where the agonist is trying to execute a movement.
True
Gluteus Maximus is an antagonist of hip extension.
False
Hamstrings are synergists of hip flexion.
False
Muscular Force Couple occurs when muscles produce forces in different linear directions resulting in torques in different rotary directions.
False
In a lever system, opposing torques can balance each other if moment arm lengths are equal.
False
Iliopsoas is a synergist of hip extension.
False
Gluteus Medius & Adductor group are stabilizers.
False
Fusiform muscles have fibers that approach their central tendon obliquely.
False
The physiologic cross-sectional area of a whole muscle reflects the amount of inactive proteins available to generate active force.
False
Pennation angle is defined as the angle of orientation between the muscle fibers and tendon.
True
In pennate muscles, such as rectus femoris, fibers run parallel to one another and to a central tendon.
False
If muscle fibers are parallel to the tendon, the pennation angle is defined as 90 degrees.
False
Physiologic cross-sectional area is proportional to the sum of the cross-sectional area of all muscle fibers.
True
Muscles with many shapes have no influence on their ultimate function.
False
Active proteins play a role in supporting the structure of muscle fibers.
True
Muscle can generate force by contracting or resisting being pulled apart.
True
Afferent feedback from the periphery helps orchestrate the amount, timing, and precision of movement.
True
Afferent impulses can only initiate from the eyes and the semicircular canals of the ears.
False
Muscle spindle consists of extrafusal fibers sensitive to muscle length and velocity changes.
False
Muscle spindle detects dynamic and static changes in muscle length.
True
Golgi tendon organ (GTO) is activated by tension and passive muscle stretch.
True
Golgi tendon organ (GTO) is located in the muscle fibers.
False
Stretch reflex, deep tendon reflex, and muscle spindle reflex are all initiated by active movement.
False
Changes in muscle receptors guide cardiovascular output and motor neuron pool excitability.
True
Complexity of innervation refers to the multiple mechanisms that regulate muscle force generation.
True
When a muscle actively shortens, the SEC will be under tension.
True
Tendons will be under tension when a muscle contracts and pull them.
True
Passive tension in stretched muscles depends on active contraction.
False
Passive tension serves the purpose of moving or stabilizing a joint against external forces.
True
Active shortening of a muscle can create passive tension in connective tissue elements.
True
The tendon is under reduced tension when a muscle is contracting.
False
When a muscle completely relaxes, the tendon is also completely relaxed.
False
Passive tension refers to tension developed in the active contractile component of the muscle.
False
Study Notes
Movement of the Body
- Movement of the body or a bone at a joint can be classified into two types: Active Movement (caused by stimulated muscles) and Passive Movement (caused by sources other than muscular contraction).
Osteokinematics
- Describes the motion of bones relative to the three cardinal planes of the body: Sagittal, Frontal, and Horizontal.
- Sagittal plane runs parallel to the sagittal suture of the skull.
- Frontal plane runs parallel to the coronal suture of the skull.
Degrees of Freedom
- Refers to the number of permitted, independent directions of angular motions allowed at a joint.
- Up to 3 degrees of angular freedom in the 3 cardinal planes.
- Clinically, the greater the degree of freedom (greater mobility) of a joint system, the greater degree of instability of that joint system.
Accessory Movement (Joint Play)
- Movement within the joint structure that is not part of the main joint movement.
- Often used to test the health of the joint.
- Excessive translation of a bone relative to the joint may indicate ligamentous injury or abnormal laxity.
- A significant reduction in translation may indicate pathologic stiffness within the surrounding periarticular connective tissues.
Neutralizer
- Muscle or muscle group that counteracts unwanted motion at the joint.
- Example: Gluteus Medius & Adductor group - Neutralizers of hip extension.
Muscular Force Couple
- When two or more muscles simultaneously produce forces in different linear directions, although resulting torques act in the same rotary direction.
Musculoskeletal Levers
- Internal and external forces produce torques through a system of bony levers.
- Important underlying concept of the lever is that with unequal moment arm lengths, the opposing torques can balance each other only if the opposing forces are of different magnitudes.
Muscle Morphology
- Muscles have different shapes that influence their function.
- Common shapes include Fusiform (e.g., biceps brachii) and Pennate (e.g., rectus femoris).
Muscle Architecture
- Two important architectural features: physiologic cross-sectional area and pennation angle.
- Physiologic cross-sectional area reflects the amount of active proteins available to generate active force.
- Pennation angle refers to the angle of orientation between the muscle fibers and tendon.
Muscle Force Generation
- Generate force through one of two basic mechanisms: contracting or resisting being pulled apart.
- Force is refined through continuous afferent feedback from the periphery.
Muscle Receptors
- Detect changes in mechanical pressure and local metabolic environment, guiding changes in cardiovascular output and motor neuron pool excitability.
- Muscle spindle detects changes in length and velocity of muscle fibers.
- Golgi tendon organ detects changes in tension and is activated by active muscle contraction or excessive passive stretch.
Muscle and Tendon: Generation of Force
- Tendons are under tension when a muscle actively shortens (contracts) and pulls them.
- Tendons are under reduced tension when a muscle is completely relaxed.
Passive Tension
- Refers to tension developed in the passive non-contractile component of the muscle.
- Created by active and passive shortening or lengthening of a muscle.
- Serves many useful purposes, such as moving or stabilizing a joint against the forces of gravity, physical contact, or other activated muscles.
Test your knowledge of the terminology related to movement in kinesiology, including active and passive movements, osteokinematics, and the three cardinal planes of the body.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
