Transcript Posture 4

Posture 4
AnteriorPosterior View
Optimal
Alignment
In an anterior view the LOG
divides the body into two
symmetrical halves
The joint axes of the hip, knee,
and ankle are equidistant from
the LOG
When postural alignment is
optimal, little or no muscle
activity is required to maintain
stability
AnteriorPosterior View
Derivation From
Optimal
Alignment
Symmetric postural deviations
such as bilateral genu valgum
cause an abnormal distribution
of weight-bearing forces on one
side of a joint and increased
tensile forces on the other side
All of this will cause increased
muscular activity and
ligamintous stress
Knee
In genu valgum, the anatomic
axes of the femur and tibia are
deviated away from optimal
vertical alignment
The gravitational moments,
which tends to produce motion
of the proximal femur laterally
and motion of the proximal tibia
medially, are greater than
normal
As a result the medial knee joint
structures are subjected to
tensile stress
The lateral portion of the
femurs are subjected to
compressive stress
These stresses may cause
changes in the medial & lateral
meniscus
The torque acting on the foot in
genu valgum tends to produce
1- Pronation of the foot
2- Stress on the medial
longitudinal arch
3- Abnormal weight bearing on
the posterior medial aspect of
the calcaneus
Foot & Toes
When one malleolus appear
more prominent or lower than
the other, a common foot
problem known as pes planus,
or flatfoot may be present
It is characterized by a reduced
or absent arch
Flatfoot may be rigid or flexible
When one malleolus appear
more prominent or lower than
the other, a common foot
problem known as pes planus,
or flatfoot may be present
It is characterized by a reduced
or absent arch
Flatfoot may be rigid or flexible
Rigid flatfoot is a structural
deformity that may be
hereditary
In rigid flatfoot the medial
longitudinal arch is absent in
non-weight bearing, toe
standing, and normal weightbearing situations
In flexible flatfoot, the arch is
reduced during normal weight
bearing situations
But it reappears during toe
standing or non-weight-bearing
situations
In rigid and flexible flatfoot, the
talar head is displaced
anteriorly, medially, and
inferiorly
This causes the depression of the
navicular and stretching of the
plantar calceneonavicular
ligament and the tibialis
posterior muscle
In the normal foot the medial
malleolus, tuberosity of the
navicular, and the head of the
first metatarsal lie in a straight
line called Feiss line
The pronated flatfoot results in
a relatively overmobile foot that
may require muscular
contraction during standing
It may also result in increased
weight bearing on the second
through forth metatarsal heads
Flatfoot interferes with push-off
during walking because the
foots is unable to assume the
supinated position and become a
rigid lever for push-off in gait
Pronation in a closed kinematic
chain causes medial rotation of
the tibia and may effect knee
joint function
The medial longitudenal arch of
the foot may be unusually high
A condition called Pes cavus
It may also be flexible or rigid
Pes cavus is more stable than
flatfoot
But the weight borne on the
lateral borders of the foot may
stretch the lateral ligaments and
the peroneus longus muscle
Three pathological conditions of
the toes may be observed
Hallux valgus
Claw toe
Hammer toe
Hallux valgus is a deformity in which there is
a lateral deviation of the great toe at the
metatarsophalangeal joint
Claw toes is a deformity in which there is
hyperextension at the metatarsophalangeal
joint combined with flexion of the distal and
proximal interphalangeal joints
Hammer toes is a deformity in which there is
hyperextension at the metatarsophalangeal
joint and the distal interphalangeal joint and
flexion in the proximal interphalangeal joint