Rami article

Question 1

What is biomechanics?

Answer 1

The study of the normal mechanics (kinetics and kinematics) in the musculoskeletal system by analysing their effects on anatomical structures

Question 2

What are the important mechanical structures of the foot?

Answer 2

The bony skeleton(provides rigidity and lever arm mechanism required to maintain balance during standing and facilitate propulsion)
The joints (confer flexibility) 
The muscles and tendons (control foot movement)

Question 3

What is the function of the bony skeleton (together with the ligaments and arches) in the foot?

Answer 3

Provides relative rigidity and the essential lever arm mechanism required to maintain balance during standing and facilitate propulsion

Question 4

How many bones are there in the foot?

Answer 4

26 bones:

• 7 tarsals
• 5 metatarsals
• 14 phalanges

Question 5

How many joints are there in the foot?

Answer 5

6 (ankle, subtalar, midtarsal, tarsometatarsal , metatarsophalangeal [MTP] and inter-phalangeal [IP] joints)

Question 6

What are the 4 sections of the foot?

Answer 6

Hindfoot
Midfoot
Forefoot
Phalanges

Question 7

What 2 bones make up the hindfoot?

Answer 7

Talus

Calcaneus

Question 8

What are the 3 parts of the talus?

Answer 8

Body
Neck
Head

Question 9

What is the purpose of the talus?

Answer 9

To transmit reactive forces from the foot through the ankle joint to the leg

Question 10

Where is the talus situated anatomically?

Answer 10

Between calcaneus and tibia

Question 11

What is the largest bone in the foot?

Answer 11

Calcaneus

Question 12

What is the purpose of the calcaneus?

Answer 12

Provides lever arm for the insertion of the Achilles tendon

Question 13

What does the Achilles tendon do?

Answer 13

One of the largest and strongest tendons in the body

through Achilles tendon gastroc and soleus impart powerful plantarflexion forces to the foot

Question 14

Why is the calcaneus able to withstand high tensile, bending and compressive forces on a regular basis without damage?

Answer 14

Due to the height, width and structure of the ACHILLES TENDON

Question 15

What structure make up the midfoot?

Answer 15

Navicular
Cuboid
3 cunieforms

Question 16

Which bone is the keystone at the top of the medial longitudinal arch?

Answer 16

Navicular

Question 17

Where is the navicular sited anatomically?

Answer 17

Medial to the cuboid

Articulates with head of the talus anteriorly

Question 18

Where is the cuboid sited anatomically?

Answer 18

Articulates with the calcaneus proximally

4th and 5th metatarsals distally

Question 19

Describe the shape of the cunieforms

Answer 19

Convexly shaped on broad dorsal aspect

Plantar surface is concave and wedge shaped so the apex of each bone points anteriorly

Question 20

What do the cunieforms articulate with distally?

Answer 20

1st, 2nd and 3rd metatarsals

Question 21

Which metatarsal is the shortest and widest?

Answer 21

1st

Question 22

What does the second metatarsal articulate with?

Answer 22

Intermediate cunieform as well as medial and lateral cunieforms in key-like fashion

Question 23

Why does the fifth metatarsal have a prominent styloid, laterally and proximally at its base

Answer 23

Insertion of the peroneus brevis

Question 24

What is a common cause of an avulsion fracture of the styloid of the fifth metatarsal?

Answer 24

When the foot is inverted against the contracting peroneus brevis muscle

Question 25

Why are the proximal and middle phalanges trochlear shaped?

Answer 25

Stability

Question 26

What is adduction of the foot?

Answer 26

When its distal aspect is angulated towards the midline

Question 27

What is abduction of the foot?

Answer 27

When the distal aspect is angulated away from the midline

Question 28

Which plane describes abduction/adduction?

Answer 28

Transverse plane

Question 29

Which plane describes plantar/dorsiflexion?

Answer 29

Sagittal plane

Question 30

Which plane describes inversion/eversion?

Answer 30

Frontal (coronal) plane

Question 31

which 3 joints in the foot have 2 degrees of freedom?

Answer 31

Midtarsal MTP IP

Question 32

What articulation makes up the ankle joint?

Answer 32

Distal tibia and body of the talus

Question 33

What is the minimum range of ankle joint motion needed for normal locomtion?

Answer 33

10 degrees dorsiflexion | 20 degrees plantarflexion

Question 34

Why is the ankle joint a bit unstable in plantarflexion?

Answer 34

Has slight movement in the transverse plane during plantarflexion

Question 35

Where does the axis of motion of the subtalar joint pass?

Answer 35

42 degrees from transverse plane | 16 degrees from the sagittal plane

Question 36

What plane is resultant motion in the subtalar joint in?

Answer 36

Frontal (coronal) plane

Question 37

What 2 joints form the midtarsal joint?

Answer 37

Talonavicular | Calcaneocuboid

Question 38

What are the 2 axes of motion of the midtarsal joint?

Answer 38

``` Oblique axis (talonavicular joint) Longitudinal axis (calcaneocuboid joint) ```

Question 39

What motion does the midtarsal joint allow?

Answer 39

Supination and pronation of the forefoot

Question 40

What motion is possible at the MTP joint?

Answer 40

Up to 90 degrees extension | Only a few degrees of flexion

Question 41

What comprises the medial arch?

Answer 41

``` Calcaneus Talus Navicular 3 cunieforms 3 metatarsals ```

Question 42

What are the pillars of the medial arch?

Answer 42

Tuberosity of the calcaneous (posteriorly) | Heads of the medial 3 metatarsal bones (anteriorly)

Question 43

What comprises the lateral arch?

Answer 43

Caclaneus Cuboid Lateral 2 metatarsal bones

Question 44

Which arch is more flexible?

Answer 44

MA

Question 45

Where do the extrinsic muscles of the foot arise from?

Answer 45

Lower leg

Question 46

Where do the intrinsic muscles of the foot arise from?

Answer 46

Within the foot itself

Question 47

What is kinematics?

Answer 47

Measurement of motion irrespective of the forces involve using cine/cameras to observe the inter-segmental relationship of the trunk and limbs

Question 48

WHat is kinetics>

Answer 48

The study of forces associated with motion using force plates, pressure platoforms and/or inshoe sensors providing a direct description/orientation of foot posture

Question 49

What is one full gait cycle?

Answer 49

Time interval between 2 consecutive heel strikes of the same foot on the ground

Question 50

What is the stride time?

Answer 50

The time interval between 2 consecutive heels strikes of the same foot

Question 51

What are the stages of GC? (For the right side)

Answer 51

``` Heel strike Forefoot loading Midstance Heel off Toe off ```

Question 52

On average what percentage of the gait cycle are stance and swing phase?

Answer 52

Stance phase = 60% | Swing phase = 40%

Question 53

What 2 factors about gait make it measurable?

Answer 53

Cyclable | Repeatable

Question 54

How many degrees of freedom do pin joints have in rigid body modelling?

Answer 54

3 degrees of freedom

Question 55

What is an internal moment a measure of?

Answer 55

What muscles are doing to combat GRF