Biomechanics Quiz 8 Flashcards
Articulation of what two bones occur on the subtalar joint?
- talus
2. calcaneus
The subtalar joint creates what planar motion? And around how many axes?
triplanar motion around 1 axis
Subtalar is critical for what?
dampening forces while maintaining foot contact with ground
The Subtalar joint rarely dislocates due to what ligament?
The interosseous talcocalcaneal ligament (ITL)
the Subtalar joint axis dorsiflexes how many degrees up from horizontal plane?
42*
the Subtalar joint axis abducts how many degrees from sagittal plane (medially)?
16*
pronation of the calcaneus with non-weightbearing involves what osteokinematics?
- everts
- abducts
- dorsi-flexes
supination of the calcaneus with non-weightbearing involves what osteokinematics?
- inverts
- adducts
- plantar-flexes
What are the 2 plantar flexors?
- gastrocnemius
2. soleus
What are the dorsi-flexors?
- tibialis interior
2. extensor digitorum longus (EVL)
What are the Evertors?
- Peroneus (Fibularis) Longus
2. Peroneus (Fibularis) Brevis
What are the Invertors?
- Tibialis Anterior
2. Tibialis Posterior
What part of the humerus is broken most often and by whom?
- the surgical neck
* by the elderly
What is the Sternoclavicular Joint?
Mechanical strut holding the scapula at a relatively constant distance from the trunk.
What is the Acromioclavicular Joint?
Firmly attaches scapula to clavicle
What is the Scapulothoracic Joint? Is it a true anatomic joint?
Provides a base of operation for the glenohumeral joint.
Not a true anatomic joint.
What is the Glenohumeral Joint?
Most distal and mobile link of the shoulder complex.
What does the Sternoclavicular (SC) Joint do?
- Links the appendicular skeleton with the axial skeleton
2. Firmly attached (stable) joint with considerable ROM
what is referred to as the “boxer’s muscle”?
The seratus anterior
What type of cartilage is the articular disc of the SC joint made of?
fibrocartilage
(SC joint kinematics) elevation and depression occur about which axis?
A/P axis
(SC joint kinematics) Protraction and Retraction occur about which axis?
vertical axis (nearly parallel to horizontal plane)
Is the SC joint a true joint?
no
What does the motion of the SC strongly associate with?
protraction and retraction of scapula
(SC joint kinematics) Axial (Longitudinal) Rotation occurs about what axis?
rotation about long axis of clavicle
(SC joint kinematics) Sternal end of clavicle spins on what?
articular disc
Acromioclavicular (AC) Joint has how many axes?
What’s its function?
non-axial
*for gliding and sliding
Kinematics of AC joint permit what kind of movements?
subtle movements between scapula and end of lateral clavicle
*multi-plane “adjustments”
Is the Scapulothoracic “Joint” a true joint?
no
Movements that occur between the scapula and thorax are a result of cooperation
between the SC and AC joints
A/C joint is what type of joint?
synovial joint
Is the scapulothoracic joint a synovial joint?
no
pronation at subtalar mostly uses?
eversion and abduction
movement in 3 planes at SC joint are involved in what?
the articular disc
