Limits of the Musculoskeletal System (Week 4) Flashcards
state what it is meant by the key term - ‘injury prevention’
injury prevention is the process of minimising the risk factors in order to reduce the likelihood of injury
what is the 4 step sequence of injury prevention outlined by (van Mechelen et al., 1992)
- establishing the extent of the injury problem
- establishing the causes and mechanisms of sports injuries
- introducing a preventative measure
- assessing its effectiveness by repeating step 1
when will injury occur
when the loads placed on the MS system in an event is greater than the mechanical limits of the structures of the MS system
state the 2 mechanical roles of the skeletal system
structural and protective
state the 2 physiological roles of the skeletal system
Ca2+ regulation and blood cell production in the bone marrow
state 2 facts about the organic component of bones
1) cells (osteoblasts, osteoclasts, osteocytes, and cell lining)
2) matrix (mostly type 1 collagen) - gives bone its flexibility
state 2 facts about the inorganic component of bone
1) mineral content (hydroxyapatite) makes bone stronger
2) hydroxyapatite - a complex salt of calcium and phosphate
state the 2 types of bone
1) cortical/compact bone
2) cancellous/spongy/trabecular bone
state 3 facts abbot cortical/compact bones
1) 80% of bone mass
2) situated on the external surfaces of bones (walls of diaphysis)
3) principally have a mechanical function
state 5 facts about cancellous/trabecular/spongy bone
1) 20% of bone mass
2) lattice of fine plates
3) situated in the epiphysis of long bones, vertebral bodies, and flat bones
4) spaces filled with bone marrow
5) reduces skeletal mass without compromising skeletal strength
state what it is meant by he key term - ‘material properties’
properties of the material itself, regardless of the specimen (i.e. - stress at which a sample of cortical bone breaks under compression)
state the two ‘material properties of bone’
1) bone density
2) compression strength of bone
state what it is meant by the key term - ‘structural properties’
- properties of a specific specimen
- i.e. - breaking stress for tibia
- more difficult to define
what are the two types of bone growth ?
1) Longitudinal growth
2) circumferential/radial growth
state 4 facts about longitudinal bone growth
1) endochondral ossification
2) primary ossification centre
3) secondary ossification cente (epiphyseal plates)
4) ceases when secondary growth plates fuse during adulthood (forms the epiphyseal line)
state 2 facts about circumferential/radial growth
1) diameter of bone increases throughout an individual’s lifespan
2) is rapid before adulthood, and is then very slow during adulthood
state what it is meant by the key term - ‘periosteum’
a layered covered membrane covering bone; muscle tendons attach to the outer layer, and the internal layer isn the site of osteoblast activity
what is the role of the periosteum during bone growth
the internal layer of the periosteum builds concentric layers of bone on too of existing bone. at the same time, bone is reabsorbed or eliminated around the circumference of the medullary cavity, so the cavity is continuously enlarged
state what it is meant by the key time - ‘bone remodelling’
the process by which bone mass is maintained, increased, or decreased
state what it is meant by the key term - ‘Wolf’s Law’
bone elements place, or displace, themselves in the direction of functional forces, and increase or decrease their mass to reflect the amount of functional forces (the bone will adapt to the loads placed upon it)
where is the sensory feedback of bone micro-damage ?
- sensory feedback from micro damage in bone
- initiates the bone remodelling response involving osteoclasts (bone resorption) and osteoblasts (bone formation)
state what it is meant by the key term - ‘functional adaptation’
the bone adapts to the loads placed upon it
what is required to maintain bone mass ?
external loads are required to maintain bone mass
