The average person’s most common problems are (in order of likelihood) tight necks, tight upper/middle back, and sore lower backs. Some of the causes of these problems are well known, but in this note I would like to consider a possible cause of all of these problems, and one that is more likely to be suffered by women rather than men (but you never can tell!) Everyone knows just how sore the feet will be after a night of dancing in elegant stiletto heels, but is that the only negative aspect of wearing high heels? Recent research from the University of Hong Kong suggests that the medium and long term effects of high heels may be more far-reaching than anyone has suspected so far, and is very likely to contribute to common musculo-skeletal problems.
Seeing inside the hip
Researchers have done some pretty high-tech manipulations of X-ray images of the hip joints in coming to this view. These ‘Fourier transforms’, as they are called, can give a highly accurate two-dimensional image of the three-dimensional structure inside bones. When applied to X-ray images of the hip joint, the researchers are able to determine the three dimensional arrangement of what’s called the ‘cancellous’ bone, the familiar porous honeycomb-like interior. The cancellous structures appear to follow the theoretical lines of force experienced by any joint, and anatomists have long believed that the structure of the bone co-evolves with the changing forces on the hip, both in an ontogenetic sense (what the individual experiences in his or her lifetime) and a phylogenetic sense (how the species evolves). The same processes drive bone deposition (and the absorption of calcium from the bloodstream) and the result is one’s characteristic internal bone structure, as well as bone density, clearly important in osteoporosis.
How long does this take?
These processes were assumed to be reasonably slow, in line with the body’s conservative approach to maintaining its resources. Imagine the researchers’ surprise when one of them happened to repeat a set of images for a young woman who had started wearing high heels for the first time in her life: in just two weeks of daily wearing of the new shoes the cancellous structures had altered in line with the changed forces on the hip! The researchers were not saying that this change necessarily had any negative connotations, but everyone was amazed at how quickly the second-hardest substance of the body can change (the enamel of the teeth is the hardest).
How high is a ‘high’ heel? This depends on the person and the length and shape of their feet, but these effects have been noticed in some people with heel heights of two inches (5 centimetres) or less. The main determinants of when a particular height of heel is likely to become significant appear to be the width of the foot (in respect of problems in the metatarsal area), and the length between heel bone and the forefoot, that part of the front of the foot that presses onto the floor, and the weight of the person. As a general rule, the lighter you are, the less a pair of high heel will press undue weight onto the forefoot, but this also depends of course on how high the heels are – as everyone knows, the really high shoes force you to virtually walk on tip-toes, putting a great deal of force through the joints of the toes in positions for which they are not ideally suited. Bunions can be a long-term result.
In addition to changing the forces on the hip joint, what other effects might there be? The most important one for overall posture seems to be the effect of high heels on the lumbar lordosis. As the heels of the feet are elevated, the top of the pelvis tends to tip forwards and the lumbar spine’s normal curve backwards (the ‘lumbar lordosis’) is increased. This doesn’t happen in isolation, of course: as the pelvis tilts the curve in the upper back can increase too, and if this happens the small curve backwards in the cervical spine is increased as well, to maintain the head’s normal position in relation to the centre of gravity of the body and to keep the head more-or-less level. Increasing the three curves of the spine means that all the muscles of the spine have to exert greater forces to maintain any posture. This extra effort can cause patterns of increased muscular tension anywhere along the spine and into the neck, and certainly can contribute to headaches. This is more likely if the patient’s job involves working behind a computer: the normal tensions experienced by these sorts of occupations are then given a new focus by the changes to the body’s posture.
Another better known effect of long-term high-heel wearing is shortened calf muscles, which can make the taking up of running or roller blading much more uncomfortable that it needs to be. If you are a high-heel devotee, make sure that you stretch the calf muscles well before and after these activities. If you are a massage therapist, spend a little extra time on your patient’s gastrocnemius and soleus. Shortened calf muscles is the main reason some patient’s calf muscles cramp at night, and is particularly common in the elderly.
Cause of other problems?
A less well-known and more insidious effect is related to the tilting of the pelvis already mentioned. Recent data collected from the workshops we run around the country suggests strongly that tight hip flexors (the muscles that lift the knee to the chest, and the ones implicated in the old now-discredited sit up exercise) are a major and often undiagnosed cause of both neck and back pain. These muscles are quite difficult to stretch using conventional methods, but there are two effective exercises offered in the revised editions of Overcome Neck & Back Pain and Stretching & Flexibility. One is a solo version, and one is done with a partner. I feel that the partner one is the best, just because the stretch effects of the standard exercises can be avoided so easily, and this version is the one the therapist can use easily in the clinic.
As a general rule, we have found that the body is expert at avoiding a necessary stretch, and the more someone needs to do one, the more likely this is to be the case. In the workshops we find that if tight hip flexors are a cause of back pain, usually one or two strong repetitions of the exercise makes the area feel more comfortable immediately. If that happens, you can be reasonably certain that these muscles are involved, and the patient will be strongly motivated to do the stretch themselves, which we suggest best be done twice a week.
So, if you love being those vital few inches higher than Nature intended, make sure that you do the right stretching exercises (forwards bends, side bends done on the floor, and rotations also done on the floor plus the core hip flexor stretches; all are illustrated in the book) and dance the night away! Be aware though that the extended wearing of high heels does seem to have long-term implications for posture, and if you have neck or back pain, you might suggest reserving those high shoes for special occasions only.