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

The lateral portion of the femurs are subjected to compressive stress 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

It is characterized by a reduced or absent arch 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

It is characterized by a reduced or absent arch 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

But it reappears during toe standing or non-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

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