Flashcards in B5 Musculoskeletal System Deck (133):
What is torque?
Force of rotational movement of bones about a joint
What is a muscle lever arm?
The perpendicular distance from an axis to the line of action of a force?
What is another term for a muscle lever arm?
What does output force require?
Long 'in' lever and a short 'out' lever
What does output speed require?
Short 'in' lever and a long 'out' lever
What are the challenges of bipedal locomotion?
Gravity and efficiency
Where does gravity act on the body?
The centre of mass
Can your centre of mass change with movement?
With relation to our bodies, what is gravity a product of?
Acceleration of gravity
Where is the human body's centre of mass?
Within the pelvis
What is stability of the body determined by?
Base of support
Position of total body centre of mass
What is gait in the simplest of words?
Pattern of interaction of limbs with the ground
What is gait divided into?
What is the definition of gait?
The period from heel strike of one limb until the next time that heel hits the ground
How much of the gait cycle does the stance phase take up?
How much of the gait cycle does the swing phase take up?
What is the stance phase of the gait cycle?
Heel strike till the toe of the same foot begins to lift off the ground
What is the swing phase of the gait cycle?
Where the limb has lost contact with the ground
What is the difference between running and walking?
Walking has one foot on the ground at all times
Running you have both feet off the ground, at some point
When lowering the forefoot to the ground, what muscles do you use?
What is eccentric contraction?
The motion of an active muscle while it is lengthening under load.
What is concentric contraction?
The motion of an active muscle while it is shortening under load.
What is the main muscle responsible for ankle dorsiflexion during heel strike?
What muscles are responsible for stopping your legs from swinging all the way backwards?
What is a reverse forward swing in terms of locomotion?
Moving your leg backwards for momentum but decelerating it to avoid doing the splits
What muscles do you use to preserve the longitudinal arch of the foot during the gait cycle?
Intrinsic muscles of foot
Long tendons of foot
What is another term for the loading response of the gait cycle?
Having a flat foot
What muscles accept your body weight during the loading response of the gait cycle?
What muscles decelerate your mass in the loading stage of the gait cycle?
What are the main ankle plantarflexors in mass deceleration of the gait cycle?
What muscles stabilise the pelvis in the loading phase of the gait cycle?
What are the main hip abductors in the gait cycle?
Minimus tensor of fascia lata
What muscles are involved in control dorsiflexion of the midstance stage of the gait cycle?
What is the point of the control dorsiflexion stage of the midstance stage of the gait cycle?
To preserve momentum
What is the last stage of the stance phase?
What does the terminal stance of the stance phase look like?
Heel coming off
What is the first stage of the swing phase?
What does the first stage of the swing phase look like?
Toe coming off
What muscles are used to accelerate mass in pre-swing of the swing phase?
Long flexors of digits
What order does the swing phase occur in?
What things can alter gait?
Artritis, inflammatory or degenerative conditions
What order does the stance phase occur in?
What is antalgic gait?
Any gait that reduces loading on the affected extremity
With reference to the gait cycle, how does antalgic gait reduce loading?
Decreasing stance phase time/ joint forces
What are examples of antalgic gait?
Having a stone in your shoe
Joint/ limb deformity
What is antaxic gait?
Unsteady, uncoordinated walk
Feet thrown out
Can't stay steady
Similar to drunk people walking
What diseases result in ataxic gait?
What is parkinsonian gait?
Involuntary movement with short, accelerating steps which are often on tip toe
Trunk flexed forward
Legs flexed stiffly at the hips and knees
What diseases cause parkinsonian gait?
Conditions affecting the basal ganglia
What is myopathic gait more commonly known as?
What is myopathic gait?
When one leg goes into swing phase the opposite leg isn't stable
What group of diseases tend to cause myopathic gait?
What is neuropathic gait more commonly known as?
High stepping gait
What disease can you see neuropathic gait in?
Peripheral nerve disease
What does neuropathic gait look like?
Lifting whole leg up higher than normal to avoid dragging the toe on the ground
What muscles are weak in neuropathic gait?
What is a trendelenburg gait?
Pelvis drops when good limb enters swing phase
Pelvis not held level when walking
What is coxa vara?
Decreased angle of the neck of the femoral bone
What is coxa valga?
Increased angle of the neck of the femoral bone?
What is the normal angle of the neck of the femoral bone?
What causes a duck waddle gait?
What is pes planus?
What are the arguments against humans being adapted for bipedalism?
What group of individuals are particularly prone to flat feet?
Overweight people who stand for long periods of time
What signals are responsible for the form of the skeleton?
What are functional signals?
Signals occurring after birth to which developing bone responds
Which embryological structures is bone derived from?
What is the process by which most bone develops?
What is another term for endochondral ossification?
In bone development, which genes are responsible for specifying the identity of the different vertebral segments?
True or false? The base of the skull develops via calcification?
False - The base develops from somites
What bones develop via intra-membranous ossification?
Flat bones of skull
How does intra-membranous ossification work?
Mesenchyme cells change to osteogenic cells and then osteoblasts
Between endochondral and intramembranous ossification, which process involves cartilage.
How does intra-chondral ossification work?
Cartilage gets vascularised and dies
Calcium is deposited
Osteoblasts and osteoclasts develop
What bones does endochrondral ossification form?
Most bones in the body, mainly long bones.
Where are the genes that determine the shape and length of the fingers?
What shape is the hand before fingers are formed?
What happens in development to form hands?
Cells between the fingers die
What are the different parts of bone?
What is the another term for physis?
Epiphyseal (growth) plate
What is the difference between cartilage and bone?
Bone is vascularised, cartilage is not.
True or false? Bone is a connective tissue?
What is the difference between chondroblasts and chondrocytes?
Chondroblasts become chondrocytes when they are surrounded by ECM
What is the purpose of chrondroblasts in bone?
What is the purpose of an extracellular matrix (ECM) in bone?
Fibres and ground substance production
Give an example of a fibre found in bone?
If cartilage is avascular, how does it recieve nutrients?
What is apositional growth?
The onion-like increase in size
What are the characteristics of apositional growth?
Growth in length
Growth in diameter
What is the difference between cancellous bone and compact bone?
Compact consists of densely packed osteons
Cancellous bone has a honeycomb like structure
What are other terms for cancellous bone?
Does bone have a more similar structure to dermal or nervous tissue?
Which bone cell is responsible for bone deposition?
Which bone cell is responsible for bone resorption?
Which bone cell is multi-nucleate?
Which joints don't move?
Which joints can move freely?
Which joint is a well known diarthroses?
What is the definition of an amphiarthroses?
A slightly movable joint
How does trabecular bone adapt to load?
Develops complementary to where load is coming from
What are the stages of bone healing?
2. Subperiosteal & endosteal cell proliferation
3. Callus- woven bone
What bone cells are key to bone remodelling?
What percentage of spongey bone is inorganic?
What contributes to the organic part of spongy bone?
Type 1 collagen
What is the difference between bone and osteoid?
Osteoid is unmineralised bone
What is the cycle of bone remodelling?
How long does bone remodelling take?
What is the name of vitamin D's active form?
1, 25 Vitamin D 3
What does the perimysium surround?
Between 10-200 muscle fibres
What does endomysium contain?
What does perimysium separate into?
What are myofibrils surrounded by?
Where is the sarcoplasmic reticulum?
Around the sarcolemma membrane
What does the I band of the sarcomere represent?
What does the A band of the sarcomere represent?
Actin and myosin
What does the H band of the sarcomere represent?
What is titin?
A protein which anchors myosin to the Z line
What is nebulin?
A protein which extends the length of actin and determines its length during assembly
What is the difference between chimpanzee and human bipedalism?
Chimpanzees move bipedally using 'bent knee bent hip'...
What is the purpose of the iliofemoral ligament in balancing?
Preventing the trunk rotating backwards at the hip
What is the purpose of the cruciate ligaments in balancing?
Helping keep the upper body and thigh from falling forwards at the knee
Where do the vertebral curves pass weight to?
The lower limb
What is the difference between the femur in humans and in apes?
The femoral head in humans is larger and its diagonal disposition makes the femur more stable.
How is the knee joint stabilised?
Soft tissues; posterior and anterior cruciate ligaments and the medial and lateral collateral ligaments
What is the 'locking mechanism'
Associated with the knee enabling it to stabilise in a fully extended position
What type of arch do primates have in their feet?
What type of arch do humans have in their feet?
What are the parts of the longitudinal arch in the feet of humans?
Why is the arch in humans important?
Medial weight transfer during mid-stance; shock absorber; better weight distribution while standing.
Where is the human body's centre of mass?
Within the pelvis anterior to S2
How is stability of a body determined?
The relationship between the base of support and the position of the total body centre of mass