a. Joints: where bones meet
immovable / sutures: bones grow together & fuse – cranium (moves during birth to fit out)
movable
gliding: any direction – vertebrae / ankle / wrist
hinge: one plane – knees / elbows
ball and socket: more than one plane – hip / shoulder
b. osteoarthritis – degenerative condition: articular cartilage broken down faster than replaced
cause: changes in collagen & glycoprotein
increase risk:
- age
- overweight – more strain on joints
- repeated vigorous flexing
- joint damage
- no genetic link
result: inflammation & swelling = pain & stiffness
- damaged/reduced cartilage: Increased friction between bones = spurs – limit movement
treatment: non-steroidal anti-inflammatory drugs / structured exercise / joint replacement
o Relief from long term pain o Surgical risks – increased blood clot / infection
o Reduced drug intake o Long recovery period
o Increased mobility o Increased dislocation risk
o Restore normal activity & quality of life o Time limit – increased risk with 2nd replacement
c. rheumatoid arthritis – autoimmune disorder:
immune system recognises joint tissue proteins as antigens – attacks bone & cartilage
increase risk: smoke / red meat / coffee / genetic
symptom: severe inflammation from increased blood flow & restricted movement (swelling & pain)
treatment: physiotherapy & NSAIDs & surgery
d. joints
1st order – seesaw 2nd order – wheelbarrow 3rd order – tweezers
middle = pivot middle = load middle = effort
force magnifier distance magnifier
tilting head standing on tiptoes biceps
o Fulcrum: where atlas o Fulcrum: toes o Fulcrum: elbow
meets skull o Load: body o Load: hand
o Load: skull o Effort: calf muscles o Effort: bicep muscles
o Effort: neck muscles
e. synovial joint
cartilage on articular surfaces – reduce friction
joint capsule + ligament (strong & flexible) – hold bones together
synovial membrane: secretes synovial fluid (lubricant & shock absorber) into synovial cavity
f. antagonistic muscles: pairs coordinate movement at joints – 1 contract & 1 relax
flexor (bend) & extensor (straighten)
Elbow:
- bicep: flexor – pulls radius = bend
- tricep: extensor – pulls ulna = straighten
tendons: strong connections between muscle & bone
86% collagen fibres – arranged in parallel
no elastic fibres: don’t stretch = ensures all movement of muscle passed to bone
immovable / sutures: bones grow together & fuse – cranium (moves during birth to fit out)
movable
gliding: any direction – vertebrae / ankle / wrist
hinge: one plane – knees / elbows
ball and socket: more than one plane – hip / shoulder
b. osteoarthritis – degenerative condition: articular cartilage broken down faster than replaced
cause: changes in collagen & glycoprotein
increase risk:
- age
- overweight – more strain on joints
- repeated vigorous flexing
- joint damage
- no genetic link
result: inflammation & swelling = pain & stiffness
- damaged/reduced cartilage: Increased friction between bones = spurs – limit movement
treatment: non-steroidal anti-inflammatory drugs / structured exercise / joint replacement
o Relief from long term pain o Surgical risks – increased blood clot / infection
o Reduced drug intake o Long recovery period
o Increased mobility o Increased dislocation risk
o Restore normal activity & quality of life o Time limit – increased risk with 2nd replacement
c. rheumatoid arthritis – autoimmune disorder:
immune system recognises joint tissue proteins as antigens – attacks bone & cartilage
increase risk: smoke / red meat / coffee / genetic
symptom: severe inflammation from increased blood flow & restricted movement (swelling & pain)
treatment: physiotherapy & NSAIDs & surgery
d. joints
1st order – seesaw 2nd order – wheelbarrow 3rd order – tweezers
middle = pivot middle = load middle = effort
force magnifier distance magnifier
tilting head standing on tiptoes biceps
o Fulcrum: where atlas o Fulcrum: toes o Fulcrum: elbow
meets skull o Load: body o Load: hand
o Load: skull o Effort: calf muscles o Effort: bicep muscles
o Effort: neck muscles
e. synovial joint
cartilage on articular surfaces – reduce friction
joint capsule + ligament (strong & flexible) – hold bones together
synovial membrane: secretes synovial fluid (lubricant & shock absorber) into synovial cavity
f. antagonistic muscles: pairs coordinate movement at joints – 1 contract & 1 relax
flexor (bend) & extensor (straighten)
Elbow:
- bicep: flexor – pulls radius = bend
- tricep: extensor – pulls ulna = straighten
tendons: strong connections between muscle & bone
86% collagen fibres – arranged in parallel
no elastic fibres: don’t stretch = ensures all movement of muscle passed to bone
