length

Question 1

what is a sarcomere

Answer 1

a basic unit of muscle contractility in skeletal muscle ( from one Z plate to another)

Question 2

myofilaments?

Answer 2

Actin (thin) and myosin (thick)
Actin and myosin overlap

Question 3

7

process of contraction

Answer 3

** Sliding filament model**
1. Action Potential
2. Myosin heads bind to Actin fibril
3. Movement of myosin head pulls actin filaments creating minute shortening of sarcomere
4. Z discs drawn closer together
5. ATP causes myosin and actin to release
6. Myosin binds to actin further down filament
7. Repeated , ratchet like movement

Question 4

muscle length relative to force

Answer 4

• ↓ muscle length → ↓ sarcomere number
• ↑ muscle length → ↑ sarcomere number
• ↓ sarcomere number & ↓ muscle length → ↑ resistance to passive stretch

Question 6

2

muscle length affects?

Answer 6

rom
force generated and where in the rom

Question 7

common patterns of spasticity

upper limb 1

Answer 7

shoulder - IR, ADD
elbow- F
forearm - S
wrist- F

Question 8

common patterns of spasticity

upper limb 2

Answer 8

shoulder - IR/ ADD
elbow- F
forearm - S
wrist- E

Question 9

common patterns of spasticity

upper limb 3

Answer 9

shoulder - IR/ADD
elbow- F
forearm - N
wrist- N

Question 10

common patterns of spasticity

upper limb 4

Answer 10

shoulder - IR/ ADD
elbow- F
forearm - P
wrist- F

Question 11

common patterns of spasticity

upper limb 5

Answer 11

shoulder - IR/ retroversion
elbow- E
forearm - P
wrist- F

Question 12

common patterns of spasticity

lower limb

Answer 12

Hip - F, IR, ADD
Knee- E
Ankle- PF, I

Question 13

arise from

contractures

Answer 13

• arise from a prolongued maintainance of a muscle in a shortened position
• biomechanical changes - fixed shortening of the muscle and contracture of periarticular structures
• may persist even if spaciticy is effectively treated

Question 14

biomechanical changes in contractures

Answer 14

1. fixed shortening of the muscle and contracture of peri-articular structures
2. reduced passive range of movement

Question 15

common contracture site

Answer 15

upper limb
- loss of finger and wrist extension
- loss of thumb extension, abd and opposition

lower limb
- loss of ankle df and e
- loss of hip abd

Question 16

contributors to stiffness

Answer 16

• Range in which you can function reduces, mid range is the strongest muscle length, if a muscle is stiffened to inner range it limits function
• when muscles are immobilised in the shortened position there is an increase in the proportion of collagen to contractile muscle
• immobilisation in a lengthened position doesnt have the same effect
• if the muscle is electrically stimulated in the shortened position sarcomere numbers still decrease but there arent connective tissue changes

Question 17

spasticity - inbalances

Answer 17

• to do with an imbalance of excitatory and inhibitory influences from CNS and exaggerated stretch responses

Question 18

common patterns of spasticity

Answer 18

LL (extensor synergy)
.
Hip
- flexes, internally rotates, adducts
Knee
- extends
Ankle
- plantarflexes with inversion