lesson 12 Flashcards
Energy requirement (ER):
The amount of food energy needed to balance energy expenditure in order to maintain body size, body composition and a level of necessary and desirable physical activity, and to allow optimal
growth and development of children, deposition of tissues duringpregnancy, and secretion of milk during lactation, consistent with long-termgood health.
Total energy expenditure (TEE):
The energy spent, on average, in a 24-hourperiod by an individual or a group of individuals. By definition, it reflects theaverage amount of energy spent in a typical day, but it is not the exactamount of energy spent each and every day.
Physical activity level (PAL)
TEE for 24 hours expressed as a multiple of BMR, TEE/BMR for 24 hours.
Lower PAL in industrial societies, but energy intake may matter more for obesity.
physical activity assumptions
- Assumption: Industrial societies are less active than ancestral ones.
Research challenges this:
- Hadza foragers: Similar total energy expenditure to Westerners when body size is controlled.
- Energy expenditure may be a physiological constant rather than culturally driven.
4 components of TEE
4 components:
1. Exercise (activity)
2. Thermogenesis (heat
production)
3. Thermic effect of food (metabolic expenditure for
digestion) and
4. Resting Energy Expenditure.
bone health and atrophy
- Bone adapts to strain: High activity increases bone strength
Cortical bone (dense): Affected by mechanical stress
Trabecular bone (spongy): More sensitive to early life activity.
- Decline in bone mass over past 20,000 years:
Linked to decreased mobility post-agriculture and sedentism.
Modern humans often show poor bone quality compared to foragers.
- Osteoporosis: Systemic decline in bone mass with age; influenced by early life activity, hormones, diet, and ecology.
Trabecular (spongy) bone
found near the ends of limb
bones, vertebrae, hips
Cortical bone
Dense, compact bone found in the shafts of long bones, near
bone surfaces, skull
disuse of bone structure
bone becomes thinner
overuse of bone structure
bone becomes thicker and stronger
repetetive movement early in life can
long term damage bone
bioarchaeology
micro-CT of trabecular bone with much higher resolution than typically possible n clinical settings
ostepenia
low bone mineral density
clinical studies of osteoporosis show
Bone loss is typical in later life, but is essentially ‘silent’… ie. it doesn’t matter until mechanical failure
BV/TV
bone volume fraction
consistently most important variable in bone mechanical variationCan be accurately estimated from pQCT scans, making archaeological and living trabecular bone
comparable
optimization (body fractures in race horses)
Balance between tissue economy and strength
distal elements
strong enough to
withstand typical loads- light to minimize energy expenditure
= tightly constrained
proximal elements
greater variability in
morphology associated with physique
common sports injuries
- Fractures – risk in strenuous/contact sports
- Strains – over stretched/torn muscles Sprains – over-stretched/torn ligaments
a. Tennis Elbow – overuse – Repetitive
Strain injury of ligaments of the elbow
b. Plantar fasciitis / shin splints –
inflammation of tendons in feet,
muscles of leg, from RS - Knee Injuries – due to impact or wear, ACL
tears, cartilage damage, dislocation,
fractures - Back Injuries – intervertebral disc damage
- Concussion – angular movement, impact to head causes brain to move inside skull, impact cranial vault
plantar faciitis
Plantar fasciitis is an inflammation of
the fibrous tissue (plantar fascia)
along the bottom of your foot that
connects your heel bone to your
toes. Plantar fasciitis can cause
intense heel pain
shin splints
refers to pain along
the shin bone (tibia) —common in
runners, dancers and military
recruits – associated with
intensification of training /
overtraining
herniated disc
(also called bulged, slipped or ruptured) is a fragment of the disc nucleus that is pushed out of the annulus, into the spinal canal or
vertebral through a tear or rupture in the annulus
shmorls nodes
herniations of the intervertebral disc material into the vertebral body
- appear as a pit in the center of a vertebral body
- result of intervertebral disk
pressure on the vertebral
bodies - commonly associated with
other forms of degenerative
change on the vertebrae - may be associated with body
mass and stature
Results: Support the hypothesis – people with
wider / rounder vertebral bodies are more
susceptible to disc herniation
spondylolysis
is a defect or abnormality of the neural arch of
vertebrae - resulting from a fatigue fracture
- Thought to be related to habitual loading, lateral rotation of the spine
