In a bid to have distinct likeable feature, one would often see a lady stand with her knees clearly bent backwards, a little more than normal and, in some cases, have both toes pointing inwardly. This posture usually causes her lower back to arch just enough to make her derriere stick out. This can be clearly observed when viewed from the side. This pose might be outstanding, but so are its potential long-term detrimental effects on the knee and surrounding joints.
The knee, in this posture is the subject of this piece. Genu recurvatum, is also known as “back knee” or knee hyperextension. Knee hyperextension, as the name suggests, is when the knee is over extended (straightened) beyond normal. This occurrence can be caused by a variety of factors, some of which include; knee ligament flexibility, unusual positioning of the foot, connective tissue disorder, unequal leg lengths and unhealthy postural habits. The solutions given in this article seek to address these. Interestingly, with or without such postural habits, women are relatively more likely to have genu recurvatum. Also, “back knee” is more common in athletes than non- athletes and is considerably difficult to treat in sports medicine. Every abnormal body posture has negative effects on other body parts.
The human body functions as a series of electrical circuit where disruption at any point affects the normal functioning of another. Though genu recurvatum occurs at the knee, its effects can be seen above and below the knee such as the lower back, the pelvis, the hip and the ankle.
In knee hyperextension, the pelvis gets tilted forward, which increases the arch at the lower back whiles the hip gets slightly flexed. In the instance when the toes are pointing inwards to accentuate the hips, the hip joints get into an almost “locked” position which is unhealthy for bearing the weight of the body. Also, at the ankle, there is an added bend to attain balance which results in uneven weight bearing. These compensations at the various joints have their negative results.
The increase in the arch of the lower back combined with the forward tilt of the pelvis, over some time, can result in lower back pain. The slight flexion at the hip coupled with the forward bending of the pelvis may also result in shortening of some hip muscles. The knee gets “locked” at the joint when it is hyperextended. This increases friction between the bones. This hyperextended position can lead to knee pain and patellofemoral dysfunction. Also, at the knee, this position can produce pain at the outer back of the knee. All these symptoms together account for decreased balance, reduced proprioception and decreased coordination. There is also decreased strength of the front thigh muscles. Finally, the uneven weight bearing is unhealthy for the ankle, which then becomes prone to injury. These can all be remedied or better still, prevented, with appropriate postural changes which comes at absolutely no cost except for effort. To correct Genu Recurvatum, one must consciously try to keep the knee not fully locked when standing. This doesn’t only prevent the dreaded “locked” position but also strengthens the front thigh muscles. In standing, stand as though a straight line can pass through the hip, knee and ankle joints to meet the ground at 90 degrees when viewed from the side.
Most people assume hyperextended knees knowingly and unknowingly over a long period of time and later accept that as their natural knee position. Postural awareness and a conscious effort is needed to avoid the long-term effects of back knee. For a more specific management plan, anyone can visit a qualified Physiotherapist.
Benjamin Kofi Essel
Physiotherapist