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  • Writer's pictureAshley Williams

Prince: Part 5 - Breakdown

Updated: Apr 2

Ramp A - N 9th St. Downtown Minneapolis, MN

In the last post we identified WHY Prince’s injury occurred. We did an overview of the anatomy and the main physical principles needed to do the analysis of Prince’s left-front jazz splits and the injury this movement in repetition likely caused him. In this post, I will explain HOW this injury occurred and introduce a few new concepts. If you did not read Prince: Part 3 - Joy in Repetition where we discussed repetitive use injuries or the last post Prince: Part 4 - Willing and Able, I would suggest you read those first.1,2 I will use terminology in this post that I have already reviewed and assume the reader is now aware of those terms.

*Again, I make this 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 symptoms or pains you are experiencing.

There are two parts to Prince’s left-front jazz splits. The first part is the drop into the splits, and the second part is the slide to stand. There are different mechanics at play with both movements, so let’s BREAKDOWN* these movements separately.

The table below summarizes the structures important for our analysis and types of stresses to which they are subjected.

When muscles do not have enough extensibility to perform a certain task, like stretching down into the splits, one of two things may happen to the muscles: Scenario 1 — The muscle stretch reflex will cause the muscle to contract, resisting stretch to avoid injury, in which case the full motion of the splits would not be completed.3 Scenario 2 — The excessive force applied on the muscles would override the reflex and result in a muscle strain or tear in which case the full motion is completed, but a muscle injury is sustained.

Since we have video evidence that Prince completed the dance move successfully more times than not, let’s take a closer look at Scenario 2.

In Scenario 2, the muscle’s stretch reflex is not acting as a safeguard against excessive motion. Without this safeguard, the ligaments are now subjected to the excess force and relied upon to complete the movement. Ligaments are not contractile like muscles so they do not have reflexes to limit excessive motion.4 Remember that the primary function of the ligaments is stability of a joint, NOT movement. Vice versa, the primary function of muscles in the extremities is for movement, NOT stability.5 How many times have you heard a doctor or athletic trainer say, “Strengthen the muscles around the joint to stabilize it”? In my opinion, this is not the most complete or holistic approach to joint rehabilitation.

Because of Prince’s habit of performing left-front jazz splits, my diagnosis of Prince’s injury would be bilateral SI joint dysfunction and pelvic instability caused by severe and repetitive sprains of the anterior and posterior sacroiliac (SI) ligaments. Lack of stability in these ligaments can lead to a multitude of pain patterns depending on the direction of the misalignment of the pelvic girdle (left os coxa/ilium, right os coxa/ilium and sacrum) and joints of the pelvic brim (right SI joint, left SI joint and pubic symphysis).6

The pain can often switch sides and the misalignment can occur bilaterally or unilaterally from day to day. I believe the primary dysfunction and presentation of Prince’s pelvis would be what chiropractors call a right ASIN ilium (right anterior, superior, internal rotation of the ilium on the sacrum). His left side would likely show an opposite presentation or a left PIEX (left posterior inferior external rotation). Torsion shear stresses are responsible for movement the ilium anterior and superior (AS) or posterior and inferior (PI) while transverse shear stresses are responsible for movement of the ilium internally (IN) or externally (EX).7

While Prince likely had many muscle strains over the years as well, I believe the source of his “hip” and low back pain actually originated from repetitive injury and loss of integrity of the sacroiliac ligaments. The pictures below are exaggerated to give you a visual of what a right ASIN ilium and left PIEX ilium would look like; however, please keep in mind, the misalignment of the pelvis does not have to be significant to cause a significant amount of pain. In fact, the misalignment is often minuscule, not readily detectable on x-ray or MRI imaging by general practitioners. Chiropractors generally do not need imaging to determine these misalignments, but instead use a number of different visual, mobility and palpation assessments to avoid exposing a patient to radiation unnecessarily.8


With loss of pelvic stability and movement of the SI joints, the sacral nerves can become impinged and cause pain patterns as visualized below.

Dermatome and myotome mapping can help us determine which nerves are impinged. Dermatomes are the nerve innervation of the areas on the skin. Myotome mapping is nerve innervation of the muscles and does not look as clean or simple in a picture because of the overlapping layers of muscles that are often innervated by more than one nerve root. Below is a dermatome map of the body and images for myotome mapping of the psoas major and gluteus medius.

In Prince: Part 3 - Joy in Repetition, we identified the right psoas major and left gluteus medius as muscles as hypertonic and likely full of trigger points due to Prince’s habit of right-sided pirouettes. These very same muscles would exacerbate the SI joint instability during a left-front jazz split.1 Lack of extensibility in the right psoas means that dropping to the splits would override the psoas reflex because it is in a disadvantaged position (external rotation of the hip) for the muscle to respond; therefore, the remainder of the applied force is placed on the SI joint and ligaments to finish the downward motion into the splits. The right psoas stretch reflex likely plays a part in the rebounding momentum that allows for the slide to stand portion of the dance move. The psoas major originates on the anterior aspects of the lumbar vertebrae, crosses the SI joint anteriorly and inserts into the lesser trochanter of the femur. In other words, the psoas major crosses both the SI joint and the hip joint. We call it a hip flexor muscle because it crosses the femoroacetabular joint (hip joint) anteriorly, but since psoas major also crosses the SI joint anteriorly, it has the ability to influence movement of the SI joint as well. We do not call psoas major an SI joint flexor, but perhaps we should. The SI joints are sometimes referred to as ‘diartho-amphiarthosis’ joints, meaning they exhibit both characteristics of diarthosis-synovial joints (freely moveable) and synarthosis joints (non-moveable).14 Therefore, it stands to reason that muscle contractions can also cause movement of these joints.

So, why would SI joint dysfunction/instability have been overlooked as a possible diagnosis? For many years doctors were under the assumption that because the SI joints are classified as stable, weight bearing joints and because SI ligaments surrounding them are so large and substantial, it would be unlikely that these joints could be moved out of alignment. We now know this is not true.15 Yes, the SI joints are classified as “stable” joints functionally, but they are structurally moveable. The SI joints can moved out of alignment specifically under the shearing stresses we discussed in the previous post.2

Spinal misalignments between the vertebrae of the spine are often undetectable at the joint by X-ray imaging because synovial joints are covered by dense joint capsules that limit (but do not eliminate movement).8 Misalignment of the SI joints are even more difficult to detect with imaging because the roughened texture and shape of the auricular surfaces makes misalignment difficult to discern. Instead of looking directly at the joints to determine misalignments, chiropractors are trained to consider patient symptoms and look at surrounding features on imaging to determine biomechanical inconsistencies in structure.7

Doctors diagnose conditions based on presentation and history. The more specific the diagnosis is, the more specific treatment can be. For example, hip pain is a general diagnosis. The patient history can give us clues as to what the more specific diagnosis would be. If the patient suffered a traumatic blow or fall, a fracture may be suspected. If the patient is mature in age, arthritic changes in the bone structure should be considered. I use this example because it was widely known that Prince had low back and hip pain. In 2010, Prince underwent a hip replacement surgery at the age of 49.16 Based on the medical examiner’s report, Prince’s hip replacement surgery would have been on the left.17 In my opinion, surgery should always be the last option after less invasive therapies have been used but found ineffective for treating pain and correcting dysfunction. According to the National Institutes of Health (NIH), the three major reasons for a hip replacement surgery for patients under the age of 55 are: #1. Broken/fractured hip (caused by avascular necrosis) #2. Advanced osteoarthritis or #3. Developmental dysplasia.18 Since Prince’s hip replacement surgery was due to chronic pain, we can rule out fracture as that would be an acute condition. Development dysplasia is typically addressed in adolescence; therefore, the only reasoning that would make sense for Prince’s doctors to decide on a hip replacement surgery is #2. Advanced osteoarthritis.

My concern is that Prince was still quite young for a hip replacement surgery. The Centers for Disease Control and Prevention (CDC) showed a trend between 2000 and 2010 for increased total hip replacements in patients between the ages of 45 and 54 and a decrease in patients total hip replacement procedures for patients over the age of 75 indicating that patients opted for this procedure earlier in life.19 The study does not indicate whether the patients were encouraged by their physicians to opt for earlier surgical procedures. Studies have shown that in many cases of even advanced or significant osteoarthritis, patients do not always present with pain. These studies warn against treatments that are based solely on radiographic confirmation of worn cartilage.20 In fact, radiographic evidence of osteoarthritis is at least twice as common as symptomatic osteoarthritis. It is a natural process that everyone will eventually go through. In other words, seeing changes of the bone on x-rays does not prove osteoarthritis is what is causing a patient’s joint pain.21 Other possible root causes of pain should be ruled out to ensure osteoarthritis is the root cause of the pain before proceeding with any surgical procedures. According to some of his close friends and family, the surgery was not successful in relieving his pain.22,23 Therefore, it is very possible the hip replacement was an unnecessary surgery that unfortunately required a heavier dosage of medication to recover from the pain of the surgery than the medication he may have already been using for pain management.

Differential diagnoses are other conditions with similar or overlapping signs and symptoms that doctors must rule out when deciding the specific diagnosis for a patient. 6

A few general differential diagnoses for SI joint dysfunction might be:

  1. Hip pain

  2. Low back pain

  3. Sciatica

(For specific differential diagnoses and clinical presentations see reference 6)

I call these general diagnoses because there are many specific causes for hip pain, another set of causes for low back pain and yet another set of causes for sciatic nerve pain. The more specific a diagnosis is, the more tailored the treatment can be to correct the root cause of the pain a patient is experiencing. I believe Prince likely experienced all of these general diagnoses but the specific diagnosis may have been overlooked and therefore he may have been treated for the incorrect specific diagnosis. Based on the presenting pain pattern of SI joint dysfunction discussed above, it is easy to see how it could be mistaken for any one of these three general differential diagnoses. This is why patient history and the mechanism of the injury (WHY and HOW the injury occurred) is so important. The specific diagnosis may change based on the mechanism of injury.

No doctors are correct 100% of the time, but it is pertinent that a diagnosis be as specific as possible and that the correct options for treatment are given to patients. In my opinion, unless the brain or spinal cord is in direct danger of being damaged due to a condition or a malignant tumor is detected, the last treatment option a patient should have to resort to is surgery. It is a doctor’s responsibility to give the best and most specific diagnosis possible, give the patient alternative options for treatment and refer out to another specialist if the best treatment option for a patient is not that particular doctor’s area of expertise.

In Prince’s case, and unfortunately the case for many celebrities and other people of influence, the danger is that most doctors would not turn down the opportunity or accolades that come with being able to say they are “the doctor to the stars” (not to mention the rate and fees they would be able to charge being a sought after doctor in their field). This might lead a doctor to hold on to a patient when they should really refer them out to another doctor who might be able to help that particular patient with a less invasive form of therapy.

As a chiropractor, I would have chosen to adjust Prince’s full spine, specifically his SI joints using multiple joint manipulation techniques depending on the presentation of his pain on a particular day, because in this type of injury the pattern of pain can change from day to day. Generally manual adjustments using Gonstead, Diversified or drop-table techniques would be sufficient for immediate relief; however, given the mechanism of his injury and knowing the root problem is chronic SI joint instability, the best long-term treatment for him would be a series of nutritional interventions and cold laser therapy to strengthen the integrity of his ligaments. I would use gentler adjustments for days with major pain flare-ups such as SOT (sacro-occipital technique) blocking or Activator technique.24 To address the trigger points in the hypertonic muscles contributing to the joint misalignment I would use either dry needling or manual trigger point therapy (if he didn’t like needles) for psoas major and gluteus medius. Finally, after the structure is restored, I would follow up with therapeutic exercises to reinforce proper biomechanics of the joint.

*For doctors: A radiologist is the best person to write imaging reports. In my opinion, anyone who cannot write a thorough detailed report has no business taking a patient’s diagnostic images (chiropractors included).8 If doctors insist on doing in-house imaging, chiropractors who do not have a DACBR (Diplomate of the American Chiropractic Board of Radiology) or other specialists who are not specifically trained in writing radiology reports should outsource to someone who is trained and practiced in detailed image reporting. It is a disservice to patients to give vague or incomplete information on their imaging reports.

*For patients: The best advice I can give is to question everything your doctor says (including me). ALWAYS get a digital copy of your own imaging (X-rays, MRI, CT, etc.) and the written report of the imaging to keep for your personal records. The written report is key. Do not be afraid to ask for a copy. They are your medical records and you have a right to access them. When in doubt or if you feel uneasy about your options, trust your gut. Get a second or even third opinion when possible before going under the knife. Having your imaging on hand is helpful because sometimes chiropractors are looking for something different that what medical practitioners are trained to look for.7

Different doctors are trained under different schools of thought. Chiropractic physicians still do not readily receive referrals from other medical practitioners; however, there are medical doctors out there who recognize how chiropractors can fit into the holistic care of their patients. I am always pleasantly surprised when a medical doctor sends me a referral. If we work as a team within healthcare, we can truly get patients the help they need. Fewer unnecessary surgeries and better patient outcomes should be the goal.

For my next Prince blog, I will discuss what happens when patients are pushed into resorting to painkillers for regular “treatment” (more accurately “suppression”) of their pain. As we all know, Prince died of an accidental fentanyl overdose. Please believe that I do not take this subject lightly. I do not particularly look forward to writing this next blog post. Just writing this last paragraph has already brought me to tears, but we do need to talk about it.


*Breakdown (Live version)

  1. Prince: Part 3 - Joy in Repetition

  2. Prince: Part 4 - Willing and Able

  3. Reschechtko S, Pruszynski JA. Stretch reflexes. Curr Biol. 2020 Sep 21;30(18):R1025-R1030. doi: 10.1016/j.cub.2020.07.092. PMID: 32961152.

  4. Özkaya, Nihat & Goldsheyder, David & Nordin, Margareta & Leger, Dawn. (2012). Fundamentals of biomechanics: Equilibrium, motion, and deformation, third edition. 10.1007/978-1-4614-1150-5.

  5. Nordin, Margareta & Frankel, Victor H.. (2013). Basic Biomechanics of the Musculoskeletal System, fourth edition.

  6. Newman DP, Soto AT. Sacroiliac Joint Dysfunction: Diagnosis and Treatment. Am Fam Physician. 2022 Mar 1;105(3):239-245. PMID: 35289578.



  9. Picture from Alphabet St. video:


  11. Slipman CW, Jackson HB, Lipetz JS, Chan KT, Lenrow D, Vresilovic EJ. Sacroiliac joint pain referral zones. Arch Phys Med Rehabil. 2000 Mar;81(3):334-8. doi: 10.1016/s0003-9993(00)90080-7. PMID: 10724079.

  12. Refai NA, Black AC, Tadi P. Anatomy, Bony Pelvis and Lower Limb: Thigh Femoral Nerve. [Updated 2022 Nov 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-.

  13. Motsinger S. K. (2020). Complete Anatomy. Journal of the Medical Library Association : JMLA, 108(1), 155–157.

  14. Vleeming, A., Schuenke, M. D., Masi, A. T., Carreiro, J. E., Danneels, L., & Willard, F. H. (2012). The sacroiliac joint: an overview of its anatomy, function and potential clinical implications. Journal of anatomy, 221(6), 537–567.

  15. Flanaghan, T.P. (2019). Age estimation of the auricular surface of the ilium : a comparison between physical examination and photographic evidence.


  17. Medical Examiner Report:

  18. Mei, X. Y., Gong, Y. J., Safir, O., Gross, A., & Kuzyk, P. (2019). Long-term outcomes of total hip arthroplasty in patients younger than 55 years: a systematic review of the contemporary literature. Canadian journal of surgery. Journal canadien de chirurgie, 62(4), 249–258.,

  19. Wolford ML, Palso K, Bercovitz A. Hospitalization for total hip replacement among inpatients aged 45 and over: United States, 2000-2010. NCHS Data Brief. 2015 Feb;(186):1-8. PMID: 25714040.

  20. Son, K. M., Hong, J. I., Kim, D. H., Jang, D. G., Crema, M. D., & Kim, H. A. (2020). Absence of pain in subjects with advanced radiographic knee osteoarthritis. BMC musculoskeletal disorders, 21(1), 640.,

  21. Sen R, Hurley JA. Osteoarthritis. [Updated 2023 Feb 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:




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