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I want to start by saying that never in a million years would I have expected to be so intrigued and excited to discuss a man’s shoe collection. According to many of the people who worked with Prince over the years, there seems to be a common sentiment that because his expectations were so high, he could draw things out of you that you didn’t know were there. I feel a similar sentiment in writing this blog. It is not something about which I would have ever expected to be so passionate.
As I begin to break down the biomechanics of Prince’s dance moves and the injuries I would expect him to have acquired over the years, I think it is essential to first discuss his footwear. Several studies have shown how high-heeled shoes cause postural compensations. In civil engineering, a bridge or building is only as strong as the foundation on which it is built. Similarly, in biomechanics, altering the foundation of the body (wearing high-heeled shoes) will inevitably effect the rest of the structure of the body. These compensations will play a role in altering the biomechanics of every dance move we discuss moving forward, so first we will start with how high heels effect the joints of the lower extremity, muscle activation and muscle tone.
*I want to make a disclaimer: I do not have access to any of Prince’s medical records and I am speaking in a strictly biomechanical analysis. Every patient is different and has other health factors to consider that can contribute to chronic pain. I am also not making any medical suggestions to the audience reading this blog. Please consult a local doctor, chiropractic or medical, for an analysis and diagnosis of any specific conditions or pains you are experiencing.
Prince’s clothes were always pushing the limits of fashion and most often accompanied by a matching pair of high-heeled booties. These heels, THE BEAUTIFUL ONES, are a testament to Prince’s artistry in every sense of the word. I would not change anything regarding the legacy of his art — music or fashion.* I am simply taking a scientific approach to assessing his injuries and how I would have approached treating those injuries if he were my patient to enable him to wear his shoes and dance the way he would want to dance for as long as possible.
According to a 2018 article by Vogue, Prince had over 3,000 pairs of shoes custom made measuring either 4 inches or 3 and 1/3 inches high.1 At Celebration 2022, I was fortunate to attend a panel of speakers including two of the five shoe makers who custom designed Prince’s shoes over the course of his career. On the panel, was also the team at Paisley Park charged with storing, preserving and showcasing his shoes for The Beautiful Collection exhibit at the museum.
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During the panel interview, the Paisley Park team shared their decision to leave the scuff marks and torn fabric on his shoes because they are part of the history of his performances. I appreciate their decision as a doctor as well because those marks are also the evidence of wear and muscle activation while he was dancing and performing. I look at my patients’ shoes everyday. It gives me subtle, but important information about their gait and where they tend to load and distribute their weight when they walk or run. So their decision to leave the wear marks on his shoes was a wiser decision than maybe they even recognize. We will return to this concept in later posts. I will also do my best to give some basic explanation for terminology that may not be familiar to readers.
It is well documented that high-heeled shoes cause postural compensations including an increased lordotic curve in the low back, forced plantarflexion of the foot and an anterior shift of the body’s center of gravity.3,4
Forced lordosis increases the pressure on the discs in the lumbar spine and can make the low back more susceptible to disc herniations, disc degeneration (spinal arthritis) and foraminal stenosis (one mechanism causing what people may refer to as a “pinched nerve”).
Prolonged plantarflexion of the ankle (talocrural or talotibial joint) can cause a forward displacement of the talus on the tibia and decrease the normal amount of dorsiflexion the ankle can perform. Full normal range of motion of the ankle is important for dynamic movements such as jumping, running and squatting. A reduced ability to perform the full range of motion at the ankle can cause additional alterations in ground reaction forces and compensations in muscle activation while performing these movements. Displacement of the talotibial joint can also lead to a peripheral nerve entrapment at the ankle causing pain and sensory changes in the foot.
Increased heel height causes an anterior (forward) shift in the body’s center of gravity and induces more pressure into the balls of the feet (metatarsophalangeal joints) and in the knees. Prolonged wear of high heels may cause pain and arthritic changes in both of these areas because of the increased pressure placed on the joints.
Beyond postural changes, high heels also cause changes in muscle activation of the lower extremity, especially in the calves (gastrocnemius and soleus), the quadriceps (rectus femoris in particular), and low back muscles (lumbar erectors).5,6,7
High heels also cause an increase in stiffness of the Achilles’ tendon which reduces the ankle’s active range of motion and changes the mechanics of the knee and ankle.5,8 When muscles are positioned in a sustained contraction, they begin to lose their extensibility and elasticity which is the ability to stretch and return to the muscles’ normal length. This can account for a muscle’s change in tone which is a small degree of contractility that helps us maintain resting posture.
I always tell my patients,“Healthy muscles are both strong and flexible”. To use another engineering analogy, bones are like levers and muscles generate a force to move the levers. If a muscle loses its elasticity, it limits the range of motion at whichever joints it crosses. Likewise, if a sustained contraction of a muscle is strong enough, it can cause a minor displacement or misalignment of the joint it crosses. However, even minor misalignments can cause major pain. This is another concept we will revisit in later posts. Specific muscle stretching is important for maintaining a balance of contractility and elasticity around the joints and for maintaining healthy muscle tone. Increased tone of the quadriceps can misalign the patella causing knee pain. Increased tone in the calf muscles can contribute to reduced range of motion of the ankle. These are all likely imbalances that contributed to Prince’s chronic pain.
For a dynamic peformer like Prince, having full range of motion and proper muscle activation would have been important to prevent injuries and allow for a faster recovery from injuries. It is likely that his shoes, as beautiful as they are, put his body in a disadvantaged posture making him more susceptible to injury and also disadvantaged for proper recovery from any musculoskeletal injuries he sustained in rehearsals or performances. The designers, to their credit, were incredibly thoughtful and innovative in creating the most glamorous, yet comfortable and sturdy heels possible for the amount of stress and punishment Prince put on his shoes. Nevertheless, no matter how well designed a pair of high heels may be, they cannot overcome the laws of physics and biomechanics. The high heels Prince wore undoubtedly amplified the stresses on his body while he was jumping, spinning, running, kicking, squatting, stomping and doing the splits. Next blog, we will start analyzing some of the specific mechanics of his dance moves.
REFERENCES
* THE BEAUTIFUL ONES — https://youtu.be/xSJAeWPEWTw https://youtu.be/xSJAeWPEWTw
Vogue shoes article: https://www.vogue.com/article/prince-heels-andre-no-1
The Beautiful Collection: https://www.paisleypark.com/exhibitions/shoes
Dai, M., Li, X., Zhou, X., Hu, Y., Luo, Q., & Zhou, S. (2015). High-heeled-related alterations in the static sagittal profile of the spino-pelvic structure in young women. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, 24(6), 1274–1281. https://doi.org/10.1007/s00586-015-3857-6
Esenyel, M., Walsh, K., Walden, J. G., & Gitter, A. (2003). Kinetics of high-heeled gait. Journal of the American Podiatric Medical Association, 93(1), 27–32. https://doi.org/10.7547/87507315-93-1-27
Simonsen, E. B., Svendsen, M. B., Nørreslet, A., Baldvinsson, H. K., Heilskov-Hansen, T., Larsen, P. K., Alkjær, T., & Henriksen, M. (2012). Walking on high heels changes muscle activity and the dynamics of human walking significantly. Journal of applied biomechanics, 28(1), 20–28. https://doi.org/10.1123/jab.28.1.20
Mika, A., Oleksy, Ł., Mika, P., Marchewka, A., & Clark, B. C. (2012). The influence of heel height on lower extremity kinematics and leg muscle activity during gait in young and middle-aged women. Gait & posture, 35(4), 677–680. https://doi.org/10.1016/j.gaitpost.2011.12.001
Mika, A., Oleksy, L., Mika, P., Marchewka, A., & Clark, B. C. (2012). The effect of walking in high- and low-heeled shoes on erector spinae activity and pelvis kinematics during gait. American journal of physical medicine & rehabilitation, 91(5), 425–434. https://doi.org/10.1097/PHM.0b013e3182465e57
Csapo, R., Maganaris, C. N., Seynnes, O. R., & Narici, M. V. (2010). On muscle, tendon and high heels. The Journal of experimental biology, 213(Pt 15), 2582–2588. https://doi.org/10.1242/jeb.044271