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Posture 4
Anterior-Posterior 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
Anterior-Posterior 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
2- Stress on the medial longitudinal arch
3- Abnormal weight bearing on the posterior medial aspect of
the calcaneus
1- Pronation of the foot
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 weight-
bearing 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
It may also result in increased weight bearing on the second
through forth metatarsal heads
The pronated flatfoot results in a relatively overmobile foot that
may require muscular contraction during standing
Pronation in a closed kinematic chain causes medial rotation of the tibia and may effect knee
joint function
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
The medial longitudenal arch of the foot may be unusually high
A condition called Pes cavus
It may also be flexible or rigid
But the weight borne on the lateral borders of the foot may
stretch the lateral ligaments and the peroneus longus muscle
Pes cavus is more stable than flatfoot
Hallux valgus
Three pathological conditions of the toes may be observed
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