What is the rolling motion?The rolling motion of the foot is a functionally very important process when walking and running slowly.
The rolling of the foot refers to the movement of the foot, taking into account the changing contact surfaces of the sole of the foot during the leg phase. In a physiological course, the 3 contact points of the arch, the heel, the small and the big toe bales are reached in any case.
The placement of the foot with the heel is the beginning of the stance phase and the rolling movement. As a result, the sole of the foot reaches the ground and the body weight is gradually taken over. The sequence of movements runs wave-like over the outer edge of the sole of the foot to the little toe ball and from there across the big toe ball and the big toe berry. The movement ends with the lifting of the hindfoot and the pushing over the big toe.
The cause of this non-linear movement is the construction of the arch of the foot, whose cavities are either bypassed, as in the longitudinal arch, or skipped, as is the case with the transverse arch. The drive for the forward thrust of the foot in the rolling movement comes at normal walking speed of the strong calf muscles, at higher speed, the hip extensors turn on.
Function & Task
The rolling motion is the guarantee that the movement on the foot takes place under mechanically favorable conditions. In conjunction with the vault structure, it ensures that the load from above is successively distributed to many elements of the foot skeleton. This is important to avoid pressure damage because the individual bones are not as strong as in the hip and knee joint.
As the sole reaches the floor through the sole of the foot, weight transfer to the heel bone and other adjacent tarsal bones begins via the talus. In the further course of the displacement of the foot forward, in the direction of the toes, the other tarsal bones and the metatarsal bones are included in the load transfer. As a result, the weight is distributed over many small bones and joints and the punctual loading of the individual parts is very low. Together with the shock absorber function of the arch of the foot, this is the main reason why arthrosis is rarely present in the ankle and other joints of the foot.
Some people do not perform any or an insufficient rolling movement. As a result, the entire body weight is transmitted to the foot in one fell swoop and not cushioned. According to the 3rd Newton Axiom acts thereby the reaction force, which arises at the ground contact upwards and loaded at each step knee joints, hip joints and spine over charge.
When running fast or jumping there is no rolling motion. The foot is placed directly with the forefoot and pressed again the next moment. There are short-term high pressure peaks that are trapped by well-trained people through the muscles.
Another important function of the rolling motion is to maintain favorable static conditions that are important to both the foot and the legs and trunk. The wave-like movement over the supporting elements of the foot skeleton ensures that the leg axes are maintained and the load in the side comparison is symmetrical. This is the basic condition for an even pressure distribution in the hip and knee joint and in the spine.
Diseases & complaints
There are many diseases and injuries that directly or indirectly affect the rolling motion. Neurological disorders associated with motor loss of control or progressive weakness of the lower leg and foot muscles have a negative effect on the gait pattern. Multiple sclerosis, polyneuropathy, as well as alcohol abuse cause gait insecurity for various reasons. The rolling movement is often no longer available and the track width is increased. The result is a typical ataxic and uncoordinated gait pattern.
All injuries associated with severe pain in the leg and in the foot have a serious effect on the walking processes. Frequently, a movement pattern is created that is used to protect and avoid pain enhancement. The unrolling falls away, the forefoot is placed directly on the ground and the other leg quickly put forward to keep the stance phase of the affected side as short as possible. This gait change is commonly referred to as limping. In fatigue fractures of the metatarsal or tarsal bones, the change in the overall picture looks similar, but the contact with the ground only occurs at the heel.
All foot deformities have a massive effect on the rolling motion and have negative consequences for the statics. The flattening or the complete degradation of the arch of the foot cause the contact surfaces to change when unrolling. In a Senkfuß that affects the longitudinal arch, the inner edge of the sole sinks and eventually reaches the ground. The wave-like movement of the unwinding is no longer given and the load distribution in the foot completely changed. Especially the inner tarsal and metatarsal bones are under heavy pressure. At the same time, the leg axis can be changed by this displacement, with the result that the involved joints are more burdened.
The fall of the transverse arch at the splay brings the heads of the metatarsals 2 - 3 under pressure. These are not as well padded as the large and small toe bales and respond to the increased burden of severe pain.
Toe deformities especially affect the last phase of the rolling motion. In hammer and claw toes, the mobility is limited especially in the extension. For this reason, the rolling motion can not take place completely. It is broken off and the gait rhythm changes.