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