The Case of a Bodybuilder with Degenerative Arthrosis
A 4l-year-old bodybuilder presents with >6-month history of left upper quadrant/shoulder pain after a weight lifting injury. While performing a 565-pound Hatfield squat, he felt the bar on his shoulders shift to the left and he heard a “very loud pop” in the left shoulder as he was going down and up. Since then, his powerlifting has been limited due to pain and poor active range of motion with abduction/external rotation. He is unable to lift weights and experiences pain “even with lifting a bottle of water.” Physical exam is remarkable for pain to palpation at the posterior glenohumeral joint and infraspinatus trigger points, 4/5 strength in the left shoulder extensor and adductor groups, limited AROM in flexion (145 degrees) (Figure 10.1) and abduction (150 degrees). Abnormal orthopedic tests include O’Brien’s (weakness and pain felt deep in the joint when testing strength in 90 degree forward flexion, 15 degree adduction, and extremity internal rotation/prona- tion), apprehension (posterior pain with limited passive abduction/external rotation) (Figure 10.2), modified Hawkins-Kennedy (pain with passive 90 degree abduction/internal rotation), and Speed’s test (weakness without pain when testing strength from 90 degree flexion in supination/external rotation and pronation/internal rotation) (Figures 10.3 and 10.4). The patient declined MR arthro- gram of the shoulder; MRI of the shoulder (>6 months after injury) revealed focal chondral thinning at superomedial aspect of humeral head (suspicious for previous impaction trauma) (Figure 10.5), degenerative arthrosis of the glenohumeral joint, degenerative changes at the superior labi um near the biceps anchor, and distal supraspinatus tendinopathy.
An Advantage of Dynamic Ultrasonography
At follow-up to review the MRI results, the posterior joint was observed with dynamic ultrasonography during passive abduction/external rotation. The humeral head translates and pivots near
FIGURE 10.1 A weight lifter with glenohumeral arthrosis and limited AROM into flexion at initial exam. Still photograph capture from video 1.
FIGURE 10.2 Apprehension test with posterior pain and limited PROM into external rotation at 90 degrees abduction (see video 2).
FIGURE 10.3 Speed’s test from supinated/externally rotated position reveals weakness without pain (see video 3).
FIGURE 10.4 Speed’s test from pronated/internally rotated position reveals weakness without pain (see video 4).
FIGURE 10.5 MRI (proton density, coronal on left; fat saturation axial on right) with evidence of previous impaction injury to posterior, superior humeral head, and cartilage degeneration of the glenoid.
the impact site, resulting in impingement of the posterior joint capsule and the deep surface of the infraspinatus tendon (Figure 10.6); the patient confirms this as the location of his posterior pain.
This posterior joint pain has now been reproduced at two appointments and two imaging studies correlate with his pain. Referral to orthopedic surgery appears to be the next step.
- 1. What is the pain generator? The answer appears clear from the MRI, yet, is this even the right question?
- 2. The impaction injury likely occurred during the weight lifting injury. Did the arthrosis/ chondromalacia pre-date this injury?
- 3. This patient suffered a unilateral injury while performing a symmetric exercise. Why did this happen?
- 4. Could biotensegrity theory, fascial anatomy, and the science of myofascial pain lead to new answers to these questions, new diagnoses, and a different treatment approach?
The value of the tensegrity model is that it provides a better means to visualize the mechanics of the
body in the light of new understanding’s about functional anatomy.
Graham Scarr, DO4
Tensegrity: The Tension Is the Frame
Tensegrity theory was developed at the intersection of art and science at Black Mountain College in North Carolina during the 1940s.6 Inspired by the geometry lectures of futurist and scientist Buckminster Fuller, Kenneth Snelson, an art student and eventually world-famous sculptor, presented a work which he described as floating compression. Professor Fuller observed the sculpture and saw continuous tension. The term tensegrity points to the fact that the integrity of the structure depends on the continuity of tension within the structure, as in this 1968 work by Snelson shown in Figure 10.7. The rods, which resist compression, did not float in stability until the tension in the cables was balanced and continuous. The energy used to tension these cables remains in the structure to this day; thus, Snelson referred to his sculptures as “forces made visible.”7 Tensegrity theory now influences numerous sciences including architecture, cell biology, robotics, and others.8-10 Some of the characteristics of tensegrity structures were recently summarized in a companion textbook to this volume11 and are included here.
FIGURE 10.6 Posterior/internal impingement at posterior shoulder. Axial images at the posterior glenohumeral joint (still images from dynamic ultrasonography; see video 5) during PROM into external rotation at 90 degrees abduction. Top image: just before impact of the labrum (L) at the deep surface of the infraspinatus tendon and joint capsule. Arrow indicates pitting from chronic impingement. Irregular signal medial and deep to the arrow corresponds to the impaction site seen on the MRI. Bottom image: moment of impact and pain at maximum external rotation with deformation of the infraspinatus tendon indicated by arrow. H—humerus; G—glenoid.
FIGURE 10.7 Tensegrity sculpture: “Needle Tower” 1968 by Kenneth Snelson. Photographs by the author at the Hirshhorn Museum and Sculpture Garden in Washington D.C., United States.
- 1. .. .are a closed, stable system of only two forces: tension and compression.
- 2. ...maintain structural integrity via continuous tension and discontinuous compression.
- 3. ...store energy as pre-stress in the tension elements.
- 4. ...create maximum stability with minimal mass.
- 5. ...instantaneously diffuse outside forces through the entire structure.
- 6. ...naturally produce oscillations without dissipating stored energy.
Since the early 1980s, orthopedic surgeon Stephen Levin M.D. has argued that traditional biomechanics can never explain biologic motion with stability.12 Dr. Levin originated the term biotensegrity to emphasize the unique qualities of biologic structures which cannot be explained by traditional biomechanics. His concern was that tensegrity applications in human-made materials are fundamentally different than biology. The most highly developed biological application of tensegrity theory was initiated by Donald Ingber to develop the science of mechanotransduction.13 If cellular mechanics follow tensegrity theory, perhaps biologic structures also follow tensegrity rules at the organism level. In discussing the hierarchical nature of tensegrity application from the cellular to tissue to organism level, Ingber et al. state “the shape stability and immediate mechanical responsiveness of all these structures depends on the pre-stress that is transmitted across their structural elements.”9 If this is true, our understanding of “musculoskeletal anatomy” would conform to the following characteristics amongst others, see below.