the musculoskeletal structures.

Bones, ligaments, cartilage, tendons, muscles & nerves.

the types of external forces.

Gravity, friction, drag & contact.

force definition.

energy used to create movement, measured in newtons (N). Two types, internal & external forces.

Internal force types.

Compressive, tensile & shear forces.

leaver definition.

a rigid bar used with force to create movement.

1st class lever definition, example & function.

Load-fulcrum-effort. usually for balancing weight and/or changing direction e.g. a seesaw.

2nd class lever definition, example & function.

Fulcrum-Load-Flea. Used to move large loads but with loss of distance e.g. a wheelbarrow & calf and body weight.

3rd class lever definition, example & function.

Fulcrum-Effort-Load. Typically used to move small loads but at a large distance e.g. shovel & bicep, forearm.

mechanical advantage definition.

when the effort arm is longer, the lever operates at a mechanical advantage. if equal it is neutral.

functions of bone.

organ protection, rigid kinematic link, sites of muscles attachment & muscle action.

composition of bone.

inorganic portion of mineral salts (60%), organic matrix of collagen (30%) & water (10%).

Osteon (Haversian system) definition and function.

the fundamental functional & structural unit of compact bone, designed for strength & nutrient transport.

compact outer layer bone name.

cortical bone (high density).

sponge inner layer bone name.

cancellous bone (loose mesh).

how much force can a bone withstand.

190 megapascals in compression, 130 megapascals in tension & 70 megapascals in shear.

tendons definition and function.

connect muscle to bone. transmit tensile load & stabilise joints.

tendon composition.

(20%) tendocytes, (80%) extracellular matrix.

extracellular matrix composition.

Elastin (2%), collagen (33-50%), proteoglycan (2%) and water (55-75%).

collagen definition and function.

collagen is synthesised by tenocytes and functions to sustain large tensile loads. collagen molecules band together in parallel arrangement to form many tendinous layers.

paratendon

tendons and ligaments are surrounded by loose areolar connectivity tissue called a paratendon.

crimp

important for biome chancel loading as it allows for the straightening during tensile loading.

ligaments definition and function.

same general composition as tendons. instead of tendocytes they have ligamentous fibroblasts. collagen fibres are not parallel. multidirectional tensile forces.

toe region definition.

lag in tensile force.

factors affecting ligaments and tendons.

aging & maturing (collagen reaches a plateau after which tensile strength and stiffness begin to decline), pregnancy (during pregnancy there is a increased laxity of tendons & ligaments in the pubic area due to increase in the hormone relaxin), mobilisation (like bone, ligaments & tendons appear to remodel in response to mechanical demands), immobilisation (decreases collagen production and thus causes a decreased tensile capacity of ligaments & tendons), comorbidities (diabetes, mellitus/connective tissue disorder/renal disease) & pharmacological agents ( intake of medications have been shown to negatively impact ligaments & tendons. mostly due to inhibition of collagen synthesis. e.g. steroids & into-imflamatory drugs).

sprain vs strain.

A sprain is a ligament injury. A strain is a muscle/tendon injury.

function of the spine.

protects spinal chord, movement ( allow, direct and control), load transfer (from head and trunk to the pelvis).

2 regions of the spine.

anterior (weight bearing zone) & posterior (provides guiding and stabalising elements).

interpretable disc functions and structure.

centre is made of nucleus pulposus and outside is annulus fibrosus. acts hydrostatically when loaded. uniform distribution of pressure.

nucleus pulposus function.

a gelatinous mass that acts like a rubber ball giving the disc elasticity and compressibility. no direct blood supply. relies on diffusion for its nutrients.

annulus fibrosus definition.

tough outer covering made of fibrocartilage. crisscross collagen fibres provide resistance to bending and torsional load.

disc degeneration.

degeneration in the disc can reduce the hydrophilic capacity. caused by lack of hydration.

cervicle facet

all movements, rotation, flexion, extension,

thoracic

rotation, lateral flexion mostly.

lumbar

sagital

male vs female spinal ROM.

males have more flex, ext. females have more lat flex.

gait

pattern of movement when walking and running

stance vs swing phase.

walking vs running.

walking has two feet on the ground at the same time.

stride length.

the length between an event on one side until the same event on the same side.

step length.

the length between an event on one side until the same event on the opposite side.

step width.

the distance covered perpendicular to the direction on location. measured at the heels.

hip during gate.

30 degree flexed and 10 degrees extends. fairly neutral amounts of ab/aduction. slight amounts of external and internal rotation, more external.

knee during extension.

Mostly extended. flexes up to 60 degrees. little bit of ab/adduction. ,maintains state of external rotation.

running gate cycle.

stance (40%), float (15%), swing (30%), float (15%). double leg support disappears.

rocking horse gait

muscular weakness / paralysis in the gluteus Maximus.

trendelenburg gait.

weak gluteus medius, leg length discrepancy.

knee fusion gait.

joint / muscle ROM limitation. leads to circumducted gait.

hemiplegic gait.

most commonly seen in stroke patients. neurological involvement.

joints of the ankle.

talocrural: plantarflexion & dorsiflexion. subtalar: inversion/eversion, abduction/adduction. midtarsal: inversion/eversion, abduction/adduction.

bone injury types:

comminuted, compression, spiral, epiphyseal, depressed, greenstick.

types of cartilage

articular (hyaline) & fibrocartilage.

cartilage composition.

chondrocytes, Collagen (15-22%), proteoglycan (4-7%) & water (60-85%).

tendon anatomy.

tendocytes (~20%) & extracellular matrix (~80%).

types of tendon injuries.

Grade 1 (some micro failure to collagen fibres. some pain is felt no joint instability). Grade 2 (partial rupture. severe pain and some joint instability). Grade 3 (total rupture has occurred (or close to). severe pain and joint completely unstable.

common tendon injuries.

tendonitis: inflammation of the tendon. tendinosis: tiny tears in the tissue in and around the tendon caused by overuse.

ligament injuries

Grade 1 (some fibres stretched or torn) RICER. Grade 2 (some fibres tom with effusion) RICER. Grade 3 (complete rupture) SURGERY. Avulsion Fracture (ligament pulls away with piece of bone.

Nerve injuries.

neuropraxia.

effects of body mass.

body mass effects the magnitude of an imposed load, this is explored through somatotyping.