Walking and gait Flashcards
what is location
ability to move from one place to another
how is walking chracterised
‘inverted pendulum‘ motion, in which the body vaults over the non-moving limb.a repeated gait cycle.
what are the diferent stages of the gait cycle and how are they charaterised
Stance phase: Accounts for 60% of the gait cycle. It can be divided into the heel strike, support and toe-off phases. from the time the heel strikes
until the toe of the same foot begins
to lift the off the ground
Swing phase: Accounts for 40% of the cycle. It can be divided into the leg lift and swing phases. the limb has ost contact with the ground
advatanges of locomation
frees our hands, elevates our
head, and allows us to move on challenging
terrain
disadvantages of locomation
Disadvantages: poses a biomechanical
challenge (efficiency and stability).
walking pattern of gait
Having one foot on the ground
at all times.
running pattern of gait
At some point during gait both feet are off the ground simultaneously. Absorbing and releasing energy stored in tendons biomechanically makes running a series of controlled leaps
When most skeletal muscles contract the
bones to which they are attached rotate
around a joint what is this rotational force
is the
torque
what are Agonists and antagonists:
agonists cause a movement through their
own contraction, antagonists oppose a
movement
what are synergist muscles
Perform or help to perform the same
motion as the agonist
what happens if mucle lenghths shortsen what is it called
what about when it lenghthens
If a muscle length shortens – concentric
If a muscle length increases - eccentric
what is a muscle lever
A muscle lever (moment) arm is the perpendicular distance to the point of rotation (the joint) from the line of muscle action
what can affect the efficienc of locomation and the pattern of gait
Alterations to the structure of the musculoskeletal system will affect the efficiency of locomotion and the pattern of gait.
what are tendons
Tendons are a tough band of
connective tissue
Connect muscle to bone
Build to endure tension
how are tendons and ligements different
ligaments join one bone to
another
what provides the brain with infromation about body postion and mvement?
Receptors in muscles and joints
provide the brain with
information about body position
and movement
3roles of the cereebellum
Cerebellum: Motor correction – adjusting movement based on sensory and proprioceptive input Motor learning- improving performance of motor sequence with repetition Balance- coordinating muscle systems across the body
what are the challenges of bipedal locomotion
Gravity and Efficiency:
Gravity acts at the centre of mass (CoM ) of each body segment and may cause
gravitational moments depending on how the limb is positioned. The size of this downward force is a product of our mass and the acceleration of
gravity.
Stability:
Challenges of Bipedal Locomotion
The human bodies CoM is positioned
within the pelvis, in the mid-line anterior
to the second sacral vertebra Stability of a body is determined by the
relationship between the BoS (Base of
support) and the position of the total body
CoM.The body maybe technically unstable but not fall provided it is moving towards a
stable solution. Ankle strategy and Hip strategy. Humans require little energy expenditure during bipedal posture (pendulum).
what are the conditons that alter gait and how
Structural damage: Normal locomotion requires nervous system, blood supply, skeleton, joints, muscles and tendons: damage to any of these structures can affect locomotion Aging: There are normal changes in gait with aging due to decreased muscle bulk and flexibility: stride length is reduced and walking becomes slower. To walk faster, the number of steps taken is increased rather than increasing the stride length. Footware: flip-flops: wearers take shorter steps and heels hit the ground with less vertical force. Toes are not brought up as much, creating a larger ankle angle and shorter stride length. High heals: The shoe's elevated heel shortens the Achilles tendon and accompanying shortening of the calf muscles. Arthritis, inflammatory or degenerative conditions: may cause pain and decrease mobility of a joint. Rheumatoid arthritis, infectious arthritis, osteoarthritis, gout and pseudogout and common causes of limp Neurological disorders: Individuals with Parkinson’s Disease walk slowly and rigidly with small, shuffling steps.
what are the gait abnormalityies
Antalgic Gait:
Any gait that reduces loading on the affected extremity by decreasing stance
phase time or joint forces as to avoid pain on weight-bearing structures.
Examples: “stone in your shoe”, diabetic foot, osteoarthritis, gout, joint or limb
deformity, ingrown toenail, and trauma.
Painful side:
A shortened stance phase time
Lengthen swing phase time
Lengthen step length
what are the pathological gaits
Ataxic gait (cerebellar gait): unsteady, uncoordinated walk, a wide base and the feet thrown out, coming down on the heel and then on the toes, double tap. Multiple sclerosis, cerebellar diseases. Parkinsonian Gait: patient involuntarily moves with short, accelerating steps, often on tiptoe, with the trunk flexed forward and the legs flexed stiffly at the hips and knees. Parkinson's disease and conditions that affect the basal ganglia Myopathic gait (Waddling gait ): With muscular diseases, the proximal pelvic girdle muscles are usually weak. The pelvis is not stabilised as leg is lifted to step forward, pelvis tilts toward the non-weight bearing leg, waddle type of gait. Neuropathic Gait (High stepping gait): Seen in peripheral nerve disease, the distal lower extremity is most affected. Because the foot dorsiflexors are weak, patient has a high stepping gait in an attempt to avoid dragging the toe.
desribe the morphological adaptatinos to human bipedalism - balancing
The supporting rectangle of quadrupedal
primates is much greater than that of bipedal
humans
In standing upright it is essential that the
body’s centre of gravity remains directly over
the supporting rectangle
desribe the morphological adaptatinos to human bipedalism -pelvis and hip
The human pelvis is shortened vertically and expanded both laterally and anteroposteriorly. Uniquely, the human ilium is wider than it is high: the reduced height brings the sacroiliac joint closer to the hip joint, reducing the stress on the ilium caused by transmitting the weight of the body from the vertebral column to the hip joint. The human iliac blade is curved and mediallyorientated, bringing the small gluteal muscles into a position where they can act as abductors of the thigh. The abductors support the pelvis when the body weight is on one leg and prevent side-toside swaying of the trunk during walking. Other thigh abductors are tensor fascia latae, sartorius, piriformis, obturator internus but these do not have the important weight-bearing role of the small glutea
desrbie the trendeleburg gait
ay prevent effective functioning of the small gluteals, leading to a characteristic gait called Trendelenburg gait. When the good limb enters swing phase, its side of the pelvis drops because the small gluteals on the opposite side cannot hold the pelvis level. To prevent a fall, the lumbar spine will be flexed towards the paralyzed side, bringing the centre of gravity of the trunk over the foot in stance phase.
desribe the morphological adaptatinos to human bipedalism:femur
The femoral head in humans is larger than those of apes: an adaptation to load bearing. The diagonal disposition of the femur re-centers support directly inferior to the trunk (body mass) to make bipedal standing more efficient and to enable bipedal walking.
what are coxa vara and valga
Coxa vara Decreased angle (< than 120°) of the femoral neck. Causes a mild shortening of the lower limb and limits passive abduction of the hip. May result in a ‘duck waddle gait’
Coxa valga Increased angle (> than 140°). Results
from weakness of the abductor muscles
and lack of normal weight-bearing forces.
Associated with neuromuscular disorders
such as cerebral palsy and poliomyelitis.
what is teh nromal angle of teh femooral neck
125 degrees
how do people get coxa vara and coxa valga?
Can be congenital or acquired by defective ossification. It may also change with any pathological process that weakens the neck of the femur (e.g. rickets).
how does the knee ensure stability
knee has a ‘locking
mechanism’, enabling it to stabilize in a
fully extended position.
Stability is ensured: the femoral and tibial
condyles are in their most close-packed
position, the anterior cruciate ligament is
tensed, the collateral ligaments are tensed
which muscles allows gthe knee to extend against gravity
Quadriceps
femoris extends
the knee against
gravity
how can the anterior cruciate ligamaent be torn
Deceleration or rotational forces acting on the weightbearing
limb
what prevents the trunk rotating backwards at
the hip joint.
what does the verterbral curve aid in
What are the secondary cervical and lumbar curves useful for
Tension of the iliofemoral ligament
prevents the trunk rotating backwards at
the hip joint.
The vertebral curves ‘cancel out’,
passing weight directly to the lower
limb.
Secondary cervical and lumbar
curves are important in balancing body
weight over the feet.
Describe the arch of the foot (1)
What does the arch of the foot allow for? (2)
Humans have a two-part longitudinal arch (one medial, one lateral).
Permit
medial weight transfer during midstance, act as a ‘shock absorber’ against forces
generated during locomotion
Distribute body weight over the sole of the foot
during standing.
how can things go wrong in the foot:
1) give example
2) what is a key factor
3) who is prone
Fallen arches occur in
many people
Behaviour is often
a key factor
Overweight individuals
who stand for long periods of time
may be particularly prone.
what happens in stance phase and swing phase
Stance: Heel strike Loading response (flat foot)) Midstance Terminal stance (heel off) Swing: Preswing (toe off) Initial Swing
1.What happens in heel strike
Lower the forefoot to the ground Continue deceleration (reverse forward swing) Preserve the longitudinal arch of the foot
2.what happnes in loading response flat floot
Accept weight Decelerate mass (slow dorsiflexion) Stabilize pelvis Preserve longitudinal arch of foot
3.what happens in midstance
Stabilise knee Control dorsiflexion (preserve momentum) Stabilize pelvis Preserve longitudinal arch of foot
4.what happens in terminal stance heel off
Accelerate mass
Stabilize pelvis
Preserve arches of
foot; fix forefoot
5.what happens in swing phase preswing toe off
Decelerate thigh; prepare for swing Accelerate mass Preserve arches of foot; fix forefoot
6.what happens in swing phase intial twing
Accelerate thigh, vary
cadence
Clear foot
7.wat happens in swing phase midswing
Clear foot
8.what happens in swing phase terminal swing
Decelerate thigh Decelerate leg Position foot Extend knee to place foot (control stride) prepare for contact
