Shoulder Biomotion Laboratory

Shoulder Biomotion Laboratory (SBL)

The Shoulder Biomotion Lab conducts studies on shoulder joint biomechanics and upper extremity nerve pathology. Our mission is to bridge basic science research with clinical applications to advance shoulder joint treatments.


The Shoulder Biomotion Laboratory is a cooperative effort under the direction of Jon Warner, MD and Guoan Li, PhD. The laboratory seeks to understand the complex motion of the human shoulder in varying states from healthy to diseased, in effort to improve treatment options. We were the first to measure the in-vivo contact locations in individuals with total shoulder arthroplasty, indicating that contact is not centered on the glenoid component. Additionally, we pioneered an inter-neural tagging technique to track nerves in three dimensions with dual plane fluoroscopy. This technique was applied to the suprascapular nerve in the shoulder.

We investigated the course of the suprascapular nerve with simulated rotator cuff muscle forces. Simulation of a massive rotator cuff and release of the transverse scapular ligament is shown in the animation (below) in purple, shows retraction of the nerve towards the spinoglenoid notch and an upward motion of the nerve at the suprascapular notch. The normal nerve course is shown in green. This retraction of the nerve may be responsible for neuropathy in many individuals with rotator cuff tearing symptoms, while releasing the ligament may help minimize pain.

Nerve motion image

We are investigating the dynamic motion of the healthy human shoulder joint with dual plane fluoroscopy. This technique was validated in a cadaver model and an animation (below) of the motion is shown. The goal of this study is to create a database of normal shoulder motion patterns from which we can compare other groups that have various pathologies, such as instability, rotator cuff tearing, and total shoulder arthroplasty.

Cadaver shoulder motion image

Group Members


Recent Publications 

  1. Massimini DF, Singh A, Wells JH, Li G, Warner JJ. Suprascapular nerve anatomy during shoulder motion: a cadaveric proof of concept study with implications for neurogenic shoulder pain. J Shoulder Elbow Surg. 2012. Jul 20. [Epub ahead of print] PMID: 22819576
  2. Massimini DF, Boyer PJ, Papannagari R, Gill TJ, Warner JP, Li G. In-vivo glenohumeral translation and ligament elongation during abduction and abduction with internal and external rotation. J Orthop Surg Res. 2012 Jun 28;7:29. PMID: 22741601
  3. Zhu Z, Massimini DF, Wang G, Warner JJ, Li G. The accuracy and repeatability of an automatic 2D-3D fluoroscopic image-model registration technique for determining shoulder joint kinematics. Med Eng Phys. 2012. Nov;34(9):1303-9. Epub 2012 Jan 29. PMID: 22285714
  4. Massimini DF, Warner JJ, Li G. Non-invasive determination of coupled motion of the scapula and humerus-An in-vitro validation. J Biomech. 2011 Feb 3;44(3):408-12. Epub 2010 Nov 4. Erratum in: J Biomech. 2011 Apr 29;44(7):1428.  PMID: 21055753
  5. Massimini DF, Li G, Warner JP. Glenohumeral contact kinematics in patients after total shoulder arthroplasty. J Bone Joint Surg Am. 2010 Apr;92(4):916-26.  PMID: 20360516
  6. Boyer PJ, Massimini DF, Gill TJ, Papannagari R, Stewart SL, Warner JP, et al. In vivo articular cartilage contact at the glenohumeral joint: preliminary report. J Orthop Sci. 2008 Jul;13(4):359-65. Epub 2008 Aug 13. PMID: 18696196


Contact Us

Shoulder Biomotion Laboratory

MGH - Jackson 12

GRJ-122355 Fruit Street Boston, MA 02114
  • Near Public Transit
  • Accessible


  • M-F, 9am-5pm

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