Muscular Force Flashcards
Force
An influence applied by one object to another, which results in the acceleration or deceleration of the second object
Length- Tension Relationship
The resting length of a muscle & the tension the muscle can produce at this resting length
Actin
The thin, stringlike, myofilament that acts along with myosin to produce muscular contraction
Myosin
The thick myofilament that acts along with actin to produce muscular contraction
Sarcomere
The structural unit of a myofibril composed of actin & myosin filaments between two Z- lines
Muscle Balance
When all muscles surrounding a joint have optimal length- tension relationships, allowing the joint to rest in a neutral position
Altered Length- Tension Relationship
When a muscle’s resting length is too short or too long, reducing the amount of force it can produce
Reciprocal Inhibition
When an agonist receives signal to contract, its functional antagonist also receives an inhibitory signal allowing it to lengthen
Muscle Imbalance
When muscles on each sides of a joint have altered length- tension relationships
Neutral Position
The optimal resting position of a joint that allows it to function efficiently through its entire normal range of motion
Stretch- Shortening Cycle
Loading of a muscle eccentrically to prepare it for a rapid concentric contraction
Series Elastic Component
Springlike non-contractile component of muscle & tendon that stores elastic energy
Amortization Phase
The transition from eccentric loading to concentric unloading during the stretch- shortening cycle
Stretch Reflex
Neurological signal from the muscle spindle that causes a muscle to contract to prevent excessive lengthening
Integrated Performance Paradigm
To move with efficiency, forces must be dampened (eccentrically), stabilized (isometrically), & then accelerated (concentrically)
Force- Velocity Curve
Describes the inverse relationship between force & velocity and refers to a muscles ability to produce tension at differing contraction velocities
Tendon
A fibrous connective tissue that connects muscle to bone
Force- Couple Relationship
The synergistic action of multiple muscle working together to produce movement around a joint
Muscles can only pull on their respective bones, true or false?
True
Local Muscular System
Generally attach on or near the vertebrae & serves the primary purpose of stabilizing the trunk. Also known as the stabilization system of the core
Joint Support Systems
Muscular stabilization systems located in joints distal (farthest) of the spine
Global Muscular System
Comprised of larger muscles that initiate movements & tend to function across one or more joints. Commonly referred to as the movement system
Subsystems of the Global Muscular System:
Deep longitudinal subsystem (LDS), posterior oblique subsystem (POS), anterior oblique subsystem (AOS), & lateral subsystem (LS)
Deep Longitudinal Subsystems (DLS)
Erector spinae, biceps femoris, tibialis anterior, peroneus longus. Includes muscles of the lower legs, hamstrings, & lower back region.
Posterior Oblique Subsystems (POS)
Latissimus dorsi, sacroiliac joint, & gluteus maximus. This is made up of the latissimus dorsi, thoracolumbar fascia (connective tissue of the low-back), & contralateral gluteus maximus and can be seen to form an “X” across the sacroiliac joint, creating stabilization.
Anterior Oblique Subsystem (AOS)
Similar to the POS but on the anterior side of the body, includes external obliques, adductors (inner) thigh muscles, & the hip external rotators. The obliques & contralateral (opposite) adductors make the “X” visualization.
Lateral Subsystem (LS)
Includes the quadratus lumborum, gluteus medius (lateral hip), tensor fascia latae, & adductors (adductor magnus) (medial thigh muscles). All side-to-side movements
Levers
Rigid bar (bone) that pivots around a stationary pivot point (fulcrum). Fulcrum is the axis point, bones are the levers, muscles create the motion (effort), resistance is weight or body part.
First- Class Levers
Fulcrum (stationary pivot point) in the middle. Effort- Fulcrum- Resistance
F-R-E-1-2-3
Second- Class Lever
Resistance (weight or body weight) in the middle, with fulcrum (pivot point) & effort (motion) on either side. Fulcrum- Resistance- Effort
F-R-E-1-2-3
Third- Class lever
Effort (motion) is in the middle, between fulcrum (pivot point) & resistance (weight or body part), most limbs operate as 3rd- class levers. Fulcrum- Effort- Resistance F-R-E-1-2-3
Rotary Motion
Movement of the bones around the joints
Torque
A force that produces rotation; common unit of measurement is the Newton meter (Nm)
