Lecture 12 (WK 13) Flashcards
How many joints are in the shoulder complex?
Four
What is the primary function of the shoulder?
- Connect the arm to the trunk
- Enable a large range of motion
NOT:
- Provide stability
- Bear high compressive loads
What are the main muscles that provide stability to the humorous? And what are they collectively called?
Main muscles:
- Supraspinatus (shoulder abduction)
- Infraspinatus (external arm rotation)
- Teres minor (external arm rotation)
Collectively called the rotator cuff
(subscapularus is also part of the rotator cuff)
Originates from the scapula and inserts into the head of the humorous
Which muscle is responssible for stabilising the scapula?
Serratus anterior
What is the general prevalence of rotator cuff injuries? And what is the prevalence between 80-89 years?
- 20.7% general prevalence
- 50% prevalence 80-89 years
What is the clincal manifestation of roator cuff injuries?
Affects people differently:
- No complaints
- Pain & limited range of motion (which affects quality of life)
What are the key motions in shoulder biomechanics?
- Extension and forwards flexion
- Abduction
- Adduction
- External rotation
What is the Empty Can (Jobe) test?
Purpose: Assesses the supraspinatus
- Patient stands or sits with their arems extended and alevated to 90 degrees in scapular plane.
- Thumps poimt down (as if emptying a can)
- Examiner applies downward resistance, patient tries to resist
Pain or weakness would suggest supraspinatus pahtology
What is the Drop arm test?
Purpose: Evaluate the integrity of the supraspinatus
- Examiner passively raises the patient’s arm to 90 degree abduction (side)
- Patient is instructed to slowly lower the arm to their side
Inability to do so or sudden droppping indicates a supraspinatus tear
What is the hornblower’s sign?
Purpose: Evaluates the teres minor muscle
- Arm is elevated to 90 degrees in scapular plane with elbow flexed to 90 degrees
- The patient externally rotates the arm against resistance
Weakness or inability to maintain position indicates teres minor pathology
What is Neer’s impingement test?
Purpose: IDentifies impingement of the rotator cuff tendons
Examiner stabilises the scapula and passively elevates the arm in flexion while internally rotating it
Pain during the maneuver suggests rotator cuff impingement
What is the primary function of biomechanics in shoulder assessments?
- Muscle strength / force evaluation
- Muscle coordination
- Joint kinematics and kinetics
What types of rotator cuff tears can you get?
- Acute / traumatic
- Degenerative (can occur naturally or can be induced by something like the mucle being pinched)
Why is marker based motion capture of the scapula not trustworthy?
Because during motion, the scapula slides under the skin and the marker will not follow it
What motions should a knee naturally be able to make in the different planes?
Sagittal:
- Flexion / extension
Frontal:
- Varus (adduction)
- Valgus (abduction)
Transverse plane:
- Internal / external rotation
Which muscles are acting on the knee joint (movement & stability)?
Flexion:
- Hamstrings (biceps femoris, semitendinosus and semimembranosus)
Extension:
- Quadricep femoris (rectus femoris, vastus lateralis, vastus medialis, vastus intermedius)
Medial rotation
Laterak rotation
What is knee osteoarthritis?
Degenerative joint disease:
- cartilage breakdown
- joint space narrowing
- also meniscal damage, ligament dysfunction, muscle atrophy
What are some symptoms of knee osteoarthritis? (3.5 answers)
- Pain
- Stiffness, reduced range of motion
- Muscle weakness
What is the prevalence of knee osteoarthritis ?
- Prevalence in people eer 40 years: 22.9%
- Higher in females
- Risk increases with age (peak at 80-84)
What are osteoarthritis risk factors?
- Age
- Overweight/Obesity
- Previous knee injury
- Female gender
What can be done to improve/change the gait patter n of patients with knee osteoarthritis & lower medial load?
- Unloading of painful knee (slower walking, smaller steps)
- Smaller knee flexion/extention range of motion
Gait modifications:
- Trunk lean (shift load to lateral side)
- Toe-out gait
Insoles
Surgery (not preferred):
- High tibial osteotomy
- Total knee replacement
When does total knee replacement typically become an option?
Often becomes treatment of choice in end-stage knee Osteoarthritis
