Podcast
Questions and Answers
The shoulder-shoulder girdle complex allows for a limited range of motion in the upper limb.
The shoulder-shoulder girdle complex allows for a limited range of motion in the upper limb.
False
The primary function of the arm is to bring the hand to any point in space.
The primary function of the arm is to bring the hand to any point in space.
True
The articular structures of the shoulder complex are primarily designed for stability.
The articular structures of the shoulder complex are primarily designed for stability.
False
The shoulder complex has 3 degrees of freedom allowing movements to occur in three planes of space.
The shoulder complex has 3 degrees of freedom allowing movements to occur in three planes of space.
Signup and view all the answers
Flexion of the shoulder occurs in the coronal plane and is limited to 45 degrees.
Flexion of the shoulder occurs in the coronal plane and is limited to 45 degrees.
Signup and view all the answers
Adduction moves a limb away from the body while abduction moves it toward the body.
Adduction moves a limb away from the body while abduction moves it toward the body.
Signup and view all the answers
The shoulder complex plays a significant role in generating movements despite its less stabilising features.
The shoulder complex plays a significant role in generating movements despite its less stabilising features.
Signup and view all the answers
The upper limb's main functions include grabbing, supporting, and reaching for objects.
The upper limb's main functions include grabbing, supporting, and reaching for objects.
Signup and view all the answers
The shoulder joint has less mobility because its surrounding structures provide significant stabilization.
The shoulder joint has less mobility because its surrounding structures provide significant stabilization.
Signup and view all the answers
The vertical axis allows for 140° of horizontal abduction.
The vertical axis allows for 140° of horizontal abduction.
Signup and view all the answers
The long axis of the humerus permits only lateral rotation.
The long axis of the humerus permits only lateral rotation.
Signup and view all the answers
Circumduction of the arm creates a perfect circular base.
Circumduction of the arm creates a perfect circular base.
Signup and view all the answers
The arm's maximal range of circumduction combines movements about three cardinal axes.
The arm's maximal range of circumduction combines movements about three cardinal axes.
Signup and view all the answers
The apex of the conical surface described by the arm is located at the shoulder joint.
The apex of the conical surface described by the arm is located at the shoulder joint.
Signup and view all the answers
The shoulder complex allows for flexion in the sagittal plane at an angle of 90°.
The shoulder complex allows for flexion in the sagittal plane at an angle of 90°.
Signup and view all the answers
Diagonal push and pull movements are characteristic of work performed by the arm.
Diagonal push and pull movements are characteristic of work performed by the arm.
Signup and view all the answers
The hand can reach all parts of the body without any trunk displacement during circumduction.
The hand can reach all parts of the body without any trunk displacement during circumduction.
Signup and view all the answers
The range of medial rotation of the humerus can extend from 70° to 120°.
The range of medial rotation of the humerus can extend from 70° to 120°.
Signup and view all the answers
The shoulder complex primarily operates in a single plane of motion.
The shoulder complex primarily operates in a single plane of motion.
Signup and view all the answers
The subacromial joint is a synovial joint consisting of distinct articulating surfaces.
The subacromial joint is a synovial joint consisting of distinct articulating surfaces.
Signup and view all the answers
The scapulothoracic joint has the characteristics of a classic synovial joint.
The scapulothoracic joint has the characteristics of a classic synovial joint.
Signup and view all the answers
The acromioclavicular joint is one of the primary interdependent linkages of the shoulder complex.
The acromioclavicular joint is one of the primary interdependent linkages of the shoulder complex.
Signup and view all the answers
The sternoclavicular joint is the main structural junction connecting the upper extremity to the sternum.
The sternoclavicular joint is the main structural junction connecting the upper extremity to the sternum.
Signup and view all the answers
The movements of the shoulder girdle primarily originate from the muscles located on the scapula.
The movements of the shoulder girdle primarily originate from the muscles located on the scapula.
Signup and view all the answers
The glenohumeral joint is often referred to as the shoulder joint.
The glenohumeral joint is often referred to as the shoulder joint.
Signup and view all the answers
The glenohumeral joint comprises both structural and functional components.
The glenohumeral joint comprises both structural and functional components.
Signup and view all the answers
Movement within the sternoclavicular joint does not influence the acromioclavicular joint.
Movement within the sternoclavicular joint does not influence the acromioclavicular joint.
Signup and view all the answers
The clavicle, scapula, and humerus are three segments of the shoulder complex that interconnect at four joints.
The clavicle, scapula, and humerus are three segments of the shoulder complex that interconnect at four joints.
Signup and view all the answers
The subacromial space serves as a functional articulation part of the shoulder complex.
The subacromial space serves as a functional articulation part of the shoulder complex.
Signup and view all the answers
The primary upward rotator muscles of the scapula include the lower fibers of the serratus anterior and the upper fibers of the trapezius during the early phase.
The primary upward rotator muscles of the scapula include the lower fibers of the serratus anterior and the upper fibers of the trapezius during the early phase.
Signup and view all the answers
The antagonists of the shoulder's flexion action include the biceps brachii and the coracobrachialis.
The antagonists of the shoulder's flexion action include the biceps brachii and the coracobrachialis.
Signup and view all the answers
The primary muscles responsible for shoulder adduction are the latissimus dorsi, teres major, and the inferior head of the pectoralis major.
The primary muscles responsible for shoulder adduction are the latissimus dorsi, teres major, and the inferior head of the pectoralis major.
Signup and view all the answers
Isotonic eccentric actions are employed by the muscles during the backward movement from a 180° elevated position.
Isotonic eccentric actions are employed by the muscles during the backward movement from a 180° elevated position.
Signup and view all the answers
Five of the seven adductor-extensor muscles connect primarily to the stable scapula.
Five of the seven adductor-extensor muscles connect primarily to the stable scapula.
Signup and view all the answers
The posterior deltoid acts as a primary mover in shoulder adduction when the arm is below 90°.
The posterior deltoid acts as a primary mover in shoulder adduction when the arm is below 90°.
Signup and view all the answers
The scapulohumeral rhythm ratio is 3:1 during the first 30° of humerus abduction.
The scapulohumeral rhythm ratio is 3:1 during the first 30° of humerus abduction.
Signup and view all the answers
A full arc of 180° of shoulder abduction consists of 60° from the GH joint and 120° from the scapulothoracic joint.
A full arc of 180° of shoulder abduction consists of 60° from the GH joint and 120° from the scapulothoracic joint.
Signup and view all the answers
During the setting phase of scapulohumeral rhythm, the humerus undergoes 30° of abduction with minimal scapula movement.
During the setting phase of scapulohumeral rhythm, the humerus undergoes 30° of abduction with minimal scapula movement.
Signup and view all the answers
The primary aim of scapulohumeral rhythm is to decrease joint congruency.
The primary aim of scapulohumeral rhythm is to decrease joint congruency.
Signup and view all the answers
In the second phase of scapulohumeral rhythm, the scapula rotates by 40° with significant protraction.
In the second phase of scapulohumeral rhythm, the scapula rotates by 40° with significant protraction.
Signup and view all the answers
The serratus anterior plays a crucial role in upward rotation of the scapula during the third phase of abduction.
The serratus anterior plays a crucial role in upward rotation of the scapula during the third phase of abduction.
Signup and view all the answers
Active insufficiency is prevented by allowing muscles to maintain a poor length-tension relation.
Active insufficiency is prevented by allowing muscles to maintain a poor length-tension relation.
Signup and view all the answers
The primary movers during a motion are also known as antagonists.
The primary movers during a motion are also known as antagonists.
Signup and view all the answers
Clavicle elevation occurs significantly in the third phase of scapulohumeral rhythm at 15°.
Clavicle elevation occurs significantly in the third phase of scapulohumeral rhythm at 15°.
Signup and view all the answers
Synergist muscles are those that oppose the desired action at a joint.
Synergist muscles are those that oppose the desired action at a joint.
Signup and view all the answers
Study Notes
The Free Upper Limb
- The upper limb is responsible for reaching, grabbing, holding, manipulating, releasing objects, supporting, and clinging.
- It is a key tool for cognition alongside the visual system.
- The upper limb is functionally composed of:
- The forming hands: The most complex part of the locomotor system.
- The arm: Brings the hand to any point in space.
The Shoulder Complex - Mobility
- The shoulder complex allows near limitless movement of the upper limb.
- Connects the upper limb to the trunk and forms the trunk-arm-hand kinetic chain.
- The shoulder complex is designed for mobility, with dynamic stability provided by muscles.
The Shoulder Complex - Degrees of Freedom
- Enables three degrees of freedom:
- Transverse axis: Allows flexion and extension.
- Antero-posterior axis: Enables abduction and adduction.
- Vertical axis: Allows flexion (horizontal adduction) and extension (horizontal abduction).
- The humerus allows for lateral and medial rotation depending on its position.
- Circumduction: A combination of movements about all three axes, creating a conical surface for reaching.
The Shoulder Complex - Components
- The shoulder complex is composed of:
-
The shoulder:
- Glenohumeral joint
- Subacromial (suprahumeral) functional joint
-
The shoulder girdle:
- Scapulothoracic functional joint
- Acromioclavicular joint
- Sternoclavicular joint
-
The shoulder:
The Shoulder Girdle
- Sternoclavicular (SC) joint: The only structural attachment of the upper limb to the axial skeleton.
- Scapulohumeral Rhythm: A coordinated movement pattern between the scapula and humerus during arm abduction.
- Scapulohumeral Rhythm Ratio: 2:1 (2° GH joint abduction & 1° ST joint upward rotation).
- The rhythm ensures efficient movement and stability, optimizing joint congruency and muscle function.
The Shoulder Movements - Phases
- Phase 1: (0-30° abduction) Minimal scapular movement and clavicle elevation.
- Phase 2: (30-40° abduction) Scapular rotation, minimal protraction or elevation, and clavicle elevation.
- Phase 3: (40-60° abduction) Significant scapular rotation, clavicle rotation, and activation of specific muscles.
Muscle Actions By Planes
- Prime mover (agonist): The primary muscle responsible for a desired motion.
- Antagonist: Opposes the desired motion.
- Secondary mover: Assists in performing the desired motion throughout the range of motion.
- Synergist: Contracts during a desired action.
Muscle Actions by Planes - Flexion
- Prime movers: Anterior deltoid, coracobrachialis, and biceps brachii.
- Secondary mover: Pectoralis major clavicular fibers.
- Antagonists: Teres minor, teres major, and infraspinatus.
Muscle Actions by Planes - Abduction
- Prime movers: Supraspinatus, middle deltoid.
- Secondary movers (synergists): Trapezius upper fibers and lower fibers, serratus anterior.
- Antagonists: Latissimus dorsi, pectoralis major, subscapularis, teres major.
Muscle Actions by Planes - Adduction 180-0°
- Prime movers: Latissimus dorsi, teres major, and sternocostal head of the pectoralis major.
- Secondary movers: Posterior deltoid, infraspinatus, coracobrachialis, teres minor, and long head of the triceps brachii.
- Antagonists: Supraspinatus and middle deltoid.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on the anatomy and functions of the upper limb, including the shoulder complex's role in mobility and degrees of freedom. Explore how the upper limb interacts with cognition and the kinetic chain connecting it to the trunk.
