MSK Anatomy/Biomechanics Flashcards
Which direction does the bone glide when it is concave moving on convex and convex moving on concave surfaces
- Concave on convex = same direction
- Convex on concave = opposite direction
What is the convex/concave rule in the spine
- Alanto-occipital joint follows the convex rule
- All joints below the 2nd vertebrae follow the concave rule
List the normal physiological end-feels
- Soft: soft tissue approximation
- Firm: capsular & ligamentous stretching
- Hard: when bone and/or cartilage meet
List the pathological end-feels
- Boggy: edema, joint swelling
- Firm with decreased elasticity: fibrosis of soft tissues
- Rubbery: muscle spasm
- Empty: loose then very hard, associated with muscle spasm/painful
- Hypermobility: end-feel at a later time than on opposite side
Close/open-packed position for vertebral
- Open: midway bw flexion/extension
- Close: max extension
Close/open-packed position TMJ
- Open: jaw slightly open
- Close: clenched jaw or max opening
Close/open-packed position GHJ
- Open: scapular plane; 40-55º ABD and 30º horizontal ABD
- Close: max ABD and ER
Close/open-packed position humeroulnar joint
- Open: 70º flexion & 10º supination
- Close: full extension and supination
Close/open-packed position humeroradial joint
- Open: full extension and supination
- Close: 90º flexion and 5º supination
Close-packed position radioulnar joint
- 5º supination
Close/open-packed position MCP
- Open: slight flexion
- Close: full flexion; full opposition (thumb)
Close/open-packed position IP
- Open: slight flexion
- Close: full extension
Close/open-packed position hip
- Open: 30º flexion, 30º ABD, slight lateral rotation (ER)
- Close: full extension, ABD, and IR
Close/open-packed position knee
- Open: 25º flexion
- Close: full extension and ER
Close-packed position toes
- Full extension
Close/open-packed position talocrual
- Open: midway bw INV/EVR and 10º PF
- Close: full DF
Close/open-packed position subtalar
- Open: midway bw ROM
- Close: full inversion
Close/open-packed position midtarsal
- Open: midway bw ROM
- Close: full supination
Close/open-packed position tarsometatarsal
- Open: midway bw supination and pronation
- Close: full supination
Capsular restriction patterns for OA joint
- Flexion limited more than extension (flexion > extension)
Capsular restriction patterns for AA joint
- limited rotation
Capsular restriction patterns for lower cervical spine
- SBing and rotation > extension
- Flexion is in tact
Capsular restriction patterns for GHJ
- ER > ABD > IR
Capsular restriction patterns for elbow
- Flexion more limited than extension
- Pronation = supination limitations
Capsular restriction patterns for wrist
- Flexion is equally limited as extension
Capsular restriction patterns for fingers
- Flexion > extension
Capsular restriction patterns for thoracic spine
- SBing and rotation > extension > flexion
Capsular restriction patterns for lumbar spine
- SBing and rotation > extension > flexion
Capsular restriction patterns for hip
- Flexion & IR > ABD
Capsular restriction patterns for knee
- Flexion > extension
Capsular restriction patterns for foot
- PF > DF
- IVR > EVR
- Supination > pronation
Describe a Tenodesis grip
- Passive finger flexion by contraction of wrist extensors when fingers are weak
Osteology of humeral head
- Articular surface covered in hyaline cartilage
- Head is retroverted 20-30º
- Longitudinal axis of head is 135º from axis of neck
Orientation of glenoid fossa places true abduction at
- 30º anterior to frontal plane
Archeology of sternoclavicular joint
- Convex superior/inferior and concave anterior/posterior articulates with reciprocal shape of sternum
- Both articulations covered with fibrocartilage
Function of the coracohumeral ligament
- Reinforces biceps tendon, superior capsule & prevent caudal (tail/bottom) dislocation of humerus
- Taut with ER
Function of coracoacrominal ligament
- Not a “true” ligament
- Connects two points of same bone
Function of the transverse humeral ligament
- Passes over bicipital groove
- Acts as retinaculum for long biceps tendon
Function of glenohumeral ligaments and what motions they limit
- Reinforce GHJ capsule anteriorly and inferiorly
- Superior GH lig.: limits ER and inferior translation
- Middle GH lig.: limits ER and anterior translation
- Inferior GH lig.: Anterior band limits ER & anterior/superior translation; Posterior band limits IR & anterior translation
At ~_____ of elevation, ER (conjunction rotation) occurs, preventing compression of greater tubercle against the acromion
- ~75º of shoulder elevation