Human locacmotion L2 Flashcards
Advantages of the locomotor system
Frees our hands,
elevates our heads
Can move on challenging terrain
Gait cycle definition
The period from heel strike of one limb until the next time that heel hits the ground
What is stance phase
First 60%
heel strike- toe of same foot lifting off
What is swing phase
40% the limb has lost contact with the ground.
Defines a walk pattern
Having 1 foot on the floor at all times
Defines a running pattern
At some point during gait both feet are off the ground simultaneously
Absorbing and releasing energy stored in tendons biomechanically
A series of controlled leaps
What is a torque
The rotational force around a joint
What is an agonist
Cause a movement through there own contraction
What is an antagonist
oppose movement (e.g hamstrings and quadriceps)
What is a synergist muscle
Perform or help to perform the same movement as a agonist
Concentric contraction
Muscle length shortens
eccentric contraction
muscle length increases
What is a moment
the turning effect of a force around a fixed point called a pivot M= F x D (force x distance)
What is a tendon
Muscle to bone
Tough band of connective tissue
Built to endure tension
Ligaments
Bone to bone
Work with tendons to pull on a bone
Cerebellum
Motor correction
based on sensory & proprioceptive input
Motor learning=
improving performance of motor sequence with repetition (in cerebellum)
Balance=
Coordinating muscle systems across the body
Flexion=
The reduction of a angle at a joint (forward)
Extension=
The extension of an angle at a joint (backwards)
Abduction=
Taking the limb away from midline
Adduction
Moving towards the midline
Plantar flexion
Moving toes down
Dorsiflexion
lifting the toes up
Gluteus maximus contracts—>
Main extension at hip
Attached to dorsal aspect of iliac blade
Inserts proximal aspect of the femur
Gluteus medius and minimus–>
abduction at the hip
attached to iliac crest/blade
where is the Sartorius muscle
anterior Thigh
Longest muscle in human body
what do quadriceps do?
Extension at the knee
Flexion at the thigh
What do hamstrings do?
Flexion at the knee
extension at the thigh
What does Tibialis anterior do?
Rotation at the ankle
Contraction lifts toes up (dorsiflexion)
Gastrocnemius Where? Does what?
Attaches around the ankle joint
contraction moves toes down (plantar flexion)
Intrinsic muscles of the foot and long tendons of the foot
Very good at stabilising the foot ( preserve the longitudinal arch of foot)
Where does gravity act
The centre of mass
The downwards force=
mass x acceleration of gravity
Advantage of CoM being closer to joint/point of movement=
less muscle force required to keep body stable
Where is the humans CoM?
Pelvis, mid-line anterior to second sacral vertebra
Where does the CoM need to act within
the base of support
What strategies are used to keep the body stable
Hip and ankle strategy
What effect can flip flops have on gait
Take shorter steps
The heel hits the ground with less force
toes not brought up as much –> larger ankle angle
what effect would high heels have on gait
Shortens the Achilles tendon and the calf muscles
What is antalgic gait?
Any gait that reduces loading ‘stone in shoe’
–> shortened stance phase
lengthen swing phase time and step length
Ataxic gait (cerebellar gait)=
unsteady, wide base
Caused by MS, cerebellar disease
parkinsonian gait=
Involuntarily moves with accelerating steps, often tiptoe
Myopathic gait= (waddling gait)
Proximal pelvis muscles are weak
–> pelvis not stabilised so tilts to non-weight bearing side
Neuropathic gait (high stepping)
Peripheral disease–> lower extremity
Week dorsiflexors high stepping to avoid dragging toe
What does the reduction in ilium height mean
Means sacroiliac joint is closer to hip joint reducing stress
What does curved iliac blade mean?
Small gluteal muscles are now in a position they can act as abductors of the thigh
what do the abductors of the hip do?
support the pelvis when body weight is on one side.
trendelenburg gait
prevents effective functioning of small gluteals, effects one side
Upper body rotates to the effected side
How id the femur adapted to humans
larger in human
Change in orientation (the bicondylar angle) –> Bringing weight closer to the base of support
What is coxa vera
decreased angle (<120) of the femoral neck
- -> mild shortening of limb
- -> duck waddle
What is coxa valga
Increased angle (>140) results from weakness of abductor muscles and lack of normal weight bearing forces
What is closely-packed when the knee is fully extended
Femoral and tibial condyles (most closely packed when knee is fully extended)
when did bipedalism start in humans
3.5 million years ago
