Last effort Flashcards
What type of joint is the humeroradial joint?
Elbow-hinge joint
What is the primary movement allowed by the proximal radio-ulnar joint?
Supination and pronation
What type of joint is the glenohumeral joint?
Ball and socket joint
What movements are allowed by the glenohumeral joint?
- Flexion
- Extension
- Abduction
- Adduction
- Internal rotation
- External rotation
- Horizontal adduction
- Horizontal abduction
What type of joint is the acromioclavicular joint?
Planar joint
What are the primary movements allowed by the acromioclavicular joint?
Upward and downward rotation, internal rotation (protraction) and external rotation (retraction), anterior tilting (elevation), posterior tilting (depression)
What type of joint is the sternoclavicular joint?
Saddle joint
What are the primary movements allowed by the sternoclavicular joint?
- Protraction
- Retraction
- Elevation
- Depression
Movements of the scapulothoracic joint?
Elevation, depression, protraction, retraction, upward and downward rotation
What type of joint is the radiocarpal joint?
Ellipsoid joint
What are the movements allowed by the radiocarpal joint?
Flexion, extension, radial deviation, ulnar deviation
What type of joint is the 1st CMC joint?
Saddle joint
What are the movements allowed by the 1st CMC joint?
Abduction, adduction, flexion, extension
What type of joint is the femur on pelvis?
Ball and socket joint
What are the primary movements allowed by the tibiofemoral joint?
Flexion, extension, slight internal rotation and external rotation
What type of joint is the talocrural joint?
Convex on concave joint
What are the primary movements allowed by the talocrural joint?
Plantarflexion, dorsiflexion, eversion, inversion
What type of movements occur at the subtalar joint?
Pronation and supination for non-weight-bearing activities
What type of joints are present in the C-spine and lumbar spine?
Planar joints
What are the primary movements allowed by the C-spine and lumbar spine?
Flexion, extension, rotation
What is the axis of rotation typically located through in joint biomechanics?
Through the convex member of the joint
How many degrees of freedom does the shoulder joint have?
Three degrees of freedom
How many degrees of freedom does the wrist joint have?
Two degrees of freedom
What are the three fundamental movements between joint surfaces?
Roll, slide, and spin
In convex on concave joint movements, how do the roll and slide occur?
In opposite directions
In concave on convex joint movements, how do the roll and slide occur?
In the same direction
What is the closed packed position in joint biomechanics?
The position of maximum congruency of the joint
What is the loose packed position in joint biomechanics?
Any other position when the joint is not in the closed packed position
What does the stress-strain curve represent?
The relationship between stress and strain in materials
What is the elastic region in the stress-strain curve?
The region where the material returns to its original shape after deformation
What is the plastic region in the stress-strain curve?
The region where permanent deformation occurs
What is the yield point in the stress-strain curve?
The point where the material begins to deform permanently
What is the ultimate failure point in the stress-strain curve?
The point where the material fails or breaks
What is the creep phenomenon?
The tendency of a material to slowly deform permanently under the influence of mechanical stresses
What are internal forces in biomechanics?
Forces generated by muscles
What are external forces in biomechanics?
Forces acting on the body from the environment, such as gravity
What is the moment arm in biomechanics?
The perpendicular distance between the axis of rotation and the line of force
What produces torque or moment in biomechanics?
The product of a force and its moment arm
What are the three ways a muscle produces force?
Isometric, concentric, and eccentric contractions
What is isometric contraction?
Producing force without changing the muscle length
What is concentric contraction?
Producing force as the muscle shortens
What is eccentric contraction?
Producing force as the muscle lengthens
What is kinematics?
The study of motion without considering the forces that cause the motion
What is kinetics?
The study of the effects of forces on the motion of a body
What is Wolff’s Law?
The concept that bone in a healthy person will adapt to the loads under which it is placed
What are the functions of the skeleton?
Leverage, support, protection, storage, blood-cell formation
What are osteocytes?
Bone cells
What are osteoblasts?
Cells that create bone
What are osteoclasts?
Cells that resorb bone
What are the two types of bone tissue?
Cortical and cancellous
What is cortical bone?
Compact, very dense outer layer of bone
What is cancellous bone?
Spongy, very porous inner layer of bone
What are the different types of bone?
Long, short, flat, irregular, sesamoid
What is Wolff’s Law in relation to bone?
Resorption occurs in response to decreased stress, deposition occurs in response to increased stress
What are the types of loading in bone biomechanics?
Compression, tension, shear, bending, torsional
What is cartilage?
Firm, flexible connective tissue without blood supply or nerves
What is the primary function of ligaments?
To connect bone to bone
What is a simple joint?
A joint with two articulating surfaces (e.g., hip)
What is a compound joint?
A joint with three or more articulating surfaces (e.g., wrist)
What is a complex joint?
A joint with two surfaces and an articular disc or fibrocartilage (e.g., knee)
What is the primary function of skeletal muscle?
To produce movement
What is the primer mover in muscle function?
The muscle primarily responsible for a given movement
What is an assistant mover in muscle function?
Muscles contributing to movement
What is an agonist in muscle function?
Muscles creating the same joint movement
What is an antagonist in muscle function?
Muscles opposing joint movement
What is a stabilizer in muscle function?
A muscle that holds one segment still so a specific movement in an adjacent segment can occur
What is a neutralizer in muscle function?
A muscle working to eliminate undesired joint movement of another muscle
What is the belly of a muscle?
The thick central portion of the muscle
What is the epimysium?
The outside covering of a muscle
What are fascicles?
Bundles of muscle fibers
What is the perimysium?
Dense connective sheath covering a fascicle
What are muscle fibers?
Cells of skeletal muscle
What is the endomysium?
A very fine sheath covering individual muscle fibers
What is the sarcolemma?
The thin plasma membrane branching into muscle
What are myofibrils?
Rod-like strands of contractile filaments
What is the sarcoplasm?
The cytoplasm of muscle cells
What is the sarcoplasmic reticulum?
The specialized endoplasmic reticulum of muscle cells
What are t-tubules?
Extensions of the sarcolemma that protrude into the muscle
What is myosin?
The thick, dark filament in muscle fibers
What is actin?
The thin, light filament in muscle fibers
What is a sarcomere?
The unit of myosin and actin, the contractile unit of muscle
What are the regions of the sarcomere?
A band, I band, H band, M line, Z discs
What is the A band in a sarcomere?
The dark band consisting of thick myosin filaments
What is the I band in a sarcomere?
The light band consisting of thin actin filaments
What is the H band in a sarcomere?
The region in the A band where myosin and actin do not overlap
What is the M line in a sarcomere?
The mid-region thickening of the myosin filament in the center of the H band
What are the Z discs in a sarcomere?
The connecting points between successive sarcomeres
What are the different types of muscle fibers?
Type I (slow oxidative), Type IIA (intermediate fast-twitch; oxidative-glycolytic), Type IIX (fast-twitch; glycolytic)
What are the three ways a muscle attaches to bone?
Directly, via a tendon, via an aponeurosis
What are the three functional components of the intervertebral junction?
Transverse and spinous processes, apophyseal joints, interbody joint
What is the annulus fibrosus?
The outer layer of the intervertebral disc with collagen fibers oriented about 65 degrees from vertical
What is the primary function of the elbow in biomechanics?
To allow flexion and extension movements
What is the carrying angle of the elbow?
A normal valgus angle of approximately 15 degrees
What is the average range of pronation and supination for the forearm?
75 degrees of pronation and 85 degrees of supination
What is the closed packed position of the hip?
Full extension, slight internal rotation, and slight abduction
What is the most hip congruency position?
90 degrees of flexion, moderate abduction, and external rotation
What are the pelvic tilts and their associated movements?
Anterior pelvic tilt (hip flexion), posterior pelvic tilt (hip extension)
What is active insufficiency in muscle function?
When a two-joint muscle cannot complete full range of motion across both joints
What is passive insufficiency in muscle function?
When a two-joint muscle cannot stretch maximally across both joints
What are the primary movements allowed by the sternoclavicular joint?
Elevation, depression, protraction, retraction
What is scapulohumeral rhythm?
For every 3 degrees of shoulder abduction, 2 degrees occur at the glenohumeral joint and 1 degree at the scapulothoracic joint
What does the acronym ‘SICK’ scapula stand for?
Scapular malposition, Inferior medial border prominence, Coracoid pain and malposition, Dyskinesis of the scapula
What is the natural angle of inclination for the femur?
125 degrees
What is the Q-angle in relation to the knee?
The net lateral pull exerted on the patella by the quadriceps
What is the primary function of menisci in the knee?
Shock absorption
What is the screw home mechanism of the knee?
The locking of the knee in full extension requiring about 10 degrees of external rotation
What is the ulnar tilt of the wrist?
25 degrees
What is the palmar tilt of the wrist?
10 degrees
What are the primary bones involved in the carpal tunnel?
Pisiform, hamate, scaphoid, and trapezium
What are the movements allowed by the radiocarpal and midcarpal joints?
Flexion, extension, radial deviation, ulnar deviation
What is DISI (Dorsal Intercalated Segment Instability)?
Lunate dislocates or subluxes facing dorsally
What is VISI (Volar Intercalated Segment Instability)?
Lunate dislocates or subluxes facing volarly (palmarly)
What are the primary movements allowed by the talocrural joint?
Dorsiflexion, plantarflexion
What is the medial longitudinal arch of the foot?
The arch formed by the calcaneus, talus, navicular, cuneiforms, and three medial metatarsals
What is pes planus?
Flat feet, associated with pronation
What is pes cavus?
High arch, associated with supination
What is rearfoot varus?
Over-supination at toe-off
What is rearfoot valgus?
Over-pronation at toe-off
What is the closed kinetic chain pronation?
Hip flexion, adduction, internal rotation; knee flexion with valgus stress; lower leg internal rotation; talus adduction
What is the tripod in foot biomechanics?
The points of contact at the calcaneus, fifth metatarsal, and first ray
What is a Smith’s fracture?
Volar angulation of the distal radius
What is the appearance of an osteosarcoma on imaging?
Sunburst pattern, onion-skinning, Codman triangle, cumulus cloud appearance
What is a Jones fracture?
Fracture of the base of the fifth metatarsal
What is a high ankle sprain?
Injury to the syndesmotic ligaments of the ankle
What is a Boxer’s fracture?
Fracture of the neck of the fifth metacarpal
What are the Pittsburgh knee rules?
Clinical decision rules to determine the need for knee radiographs
What is the terrible triad of the knee?
Injury involving the ACL, MCL, and medial meniscus
What is a Maisonneuve fracture?
Spiral fracture of the proximal fibula with disruption of the syndesmosis
What is osteochondritis dissecans (OCD)?
A joint condition where a variable amount of bone and its adjacent cartilage loses its blood supply
What is a SLAP tear?
Superior Labrum Anterior to Posterior tear
What are the classic findings associated with chronic rotator cuff tears?
Irregularity of the greater tuberosity, narrowing of the distance between the acromion and humeral head, erosion or loss of bone in the inferior aspect of the acromion
What is the primary function of the intervertebral disc?
To absorb and distribute loads applied to the spinal column
What is ankylosing spondylitis?
A form of arthritis that primarily affects the spine, causing inflammation and leading to chronic pain and stiffness
What is a teardrop fracture?
A fracture where a triangular fragment of bone is separated from the anteroinferior corner of the vertebral body
What is a Clay shoveler’s fracture?
An avulsion fracture of a spinous process, typically occurring in the lower cervical or upper thoracic spine
What is the function of the epimysium in muscle structure?
It is the outermost layer of connective tissue surrounding the entire muscle
What is the role of the perimysium in muscle structure?
It surrounds groups of muscle fibers, forming a fascicle
What is the endomysium?
A thin layer of connective tissue surrounding each individual muscle fiber
What are myofibrils composed of?
Repeating units called sarcomeres, which are the basic contractile units of muscle
What is the function of the sarcoplasmic reticulum in muscle cells?
To store and release calcium ions during muscle contraction
What is the difference between type I and type II muscle fibers?
Type I fibers are slow-twitch and oxidative, while type II fibers are fast-twitch and can be either oxidative-glycolytic or glycolytic
