Deltoids
Integrated functional anatomy of the anterior, middle, and posterior deltoid. Attachments, nerves, palpation, joint actions, arthrokinematics, fascia, triggerpoints, and behavior in postural dysfunction. Common exercises, foam rolling, and stretches for the deltoid/shoulder muscles.
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Course Description: Deltoids
This course describes the anatomy and integrated function of the deltoid muscle (a.k.a. the delts, shoulder muscles, or referenced individually as the anterior deltoid or front deltoid, posterior deltoid or rear deltoid, and the middle deltoid, medial deltoid, or lateral deltoid). The deltoid muscle originates on the acromion process of the scapula (shoulder blade) and the lateral 1/3 of the clavicle, all three divisions of the deltoid muscle insert into the deltoid tuberosity, and all divisions are innervated by the axillary nerve. The deltoids are the most superficial muscles of the shoulder and are composed of a relatively even proportion of type I muscle fibers and type II muscle fibers; however, these proportions can vary considerably. The deltoid muscle crosses the shoulder joint (glenohumeral joint) and contributes to shoulder joint actions. The anterior deltoid is the primary shoulder flexor and will contribute to shoulder horizontal adduction and shoulder internal rotation. The middle deltoid (lateral deltoid) is the primary shoulder abductor. And, the posterior deltoid (rear delt) is the primary shoulder horizontal abductor and will contribute to shoulder extension and shoulder external rotation. This course also describes the role of the deltoid muscles in glenohumeral arthrokinematics, fascial integration, postural dysfunction, and subsystem integration. Sports medicine professionals (personal trainers, fitness instructors, physical therapists, massage therapists, chiropractors, occupational therapists, athletic trainers, etc.) must be aware of the integrated function of the deltoids for the detailed analysis of human movement, and the development of sophisticated exercise programs and therapeutic (rehabilitation) interventions. Further, this course is essential knowledge for future courses discussing injury prevention and physical rehabilitation (e.g. deltoid pain, shoulder joint pain, “shoulder blade pain,” “uneven shoulder height,” axillary nerve damage, rotator cuff injury, shoulder impingement syndrome, scapula dyskinesis), the synergistic function of the deltoid muscles (e.g. during shoulder exercises like an upright row or a lateral raise the middle deltoid abducts the humerus in synergy with the supraspinatus of the rotator cuff), and deltoid exercises and techniques for enhancing sports performance (e.g. training the deltoids with shoulder exercises to optimize stability, strength, power, and shoulder hypertrophy, etc.).
Pre-approved credits for:
Pre-approved for Continuing Education Credits for:
- Athletic Trainers
- Chiropractors
- Group Exercise Instructors
- Massage Therapists
- Occupational Therapists
- Personal Trainers
- Physical Therapists
- Physical Therapy Assistants
- Physiotherapists
- Yoga Instructors
This Course Includes:
- AI Tutor
- Text and Illustrations
- Audio Voice-over
- Research Review
- Technique Videos
- Practice Exam
- Pre-approved Final Exam
Brookbush Institute’s most recommended techniques for the Deltoids (see videos below):
- Release: Posterior Shoulder Foam Rolling
- Stretch: Posterior Shoulder (Sleeper) Stretch
- Conditioning: Shoulder and Pressing Progressions

Study Guide: Anatomy of the Deltoids
Introduction to the Deltoids3 Sub Sections
Deltoid Muscle Actions2 Sub Sections
Fascial Integration1 Sub Section
Postural Dysfunction & the Deltoids
Exercises and Techniques for the Deltoid Muscles3 Sub Sections
Bibliography
- Phillip Page, Clare Frank, Robert Lardner, Assessment and Treatment of Muscle Imbalance: The Janda Approach © 2010 Benchmark Physical Therapy, Inc., Clare C. Frank, and Robert Lardner
- Donald A. Neumann, “Kinesiology of the Musculoskeletal System: Foundations of Rehabilitation – 2nd Edition” © 2012 Mosby, Inc.
- Leon Chaitow, Muscle Energy Techniques: Third Edition, © Elsevier 2007
- Tom Myers, Anatomy Trains: Second Edition. © Elsevier Limited 2009
- Shirley A Sahrmann, Diagnoses and Treatment of Movement Impairment Syndromes, © 2002 Mosby Inc.
- David G. Simons, Janet Travell, Lois S. Simons, Travell & Simmons’ Myofascial Pain and Dysfunction, The Trigger Point Manual, Volume 1. Upper Half of Body: Second Edition, Pg. 623 - 637 © 1999 Williams and Wilkens
- Cynthia C. Norkin, D. Joyce White, Measurement of Joint Motion: A Guide to Goniometry – Third Edition. © 2003 by F.A. Davis Company
- Cynthia C. Norkin, Pamela K. Levangie, Joint Structure and Function: A Comprehensive Analysis: Fifth Edition © 2011 F.A. Davis Company
- Florence Peterson Kendall, Elizabeth Kendall McCreary, Patricia Geise Provance, Mary McIntyre Rodgers, William Anthony Romani, Muscles: Testing and Function with Posture and Pain: Fifth Edition © 2005 Lippincott Williams & Wilkins
- Karel Lewit. Manipulative Therapy: Musculoskeletal Medicine © 2007 Elsevier
- David B. Jenkins, Hollinshead’s Functional Anatomy of the Limbs and Back: Eighth Edition © 2002 Saunders
- Inman VT, Saunders JB, Abbot JC, Observations on the function of the shoulder joint. J Bone Joint Surg 26:1 – 30, 1944
- Scovazzo, M.L., Browne, A., Pink, M., Jobe, F.W., and Kerrigan, J. (1991). The painful shoulder during freestyle swimming: An electromyographic cinematographic analysis of twelve muscles. The American Journal of Sports Medicine. 19(6). 577-582
- Lawrence, R.L., Braman, J.P., Staker, J.L., Laprade, R.F., Ludewig, P.M. (2014) Comparison of 3-dimensional shoulder complex kinematics in individuals with and without shoulder pain, Part 2: Glenohumeral joint. Journal of Orthopaedic & Sports Physical Therapy 44(9). 646-B3
- José Miota Ibarra, Hong-You Ge, Chao Wang, Vicente Martínez Vizcaíno, Thomas Graven-Nielsen, Lars Arendt-Nielsen. Latent Myofascial Trigger Points are Associated With an Increased Antagonistic Muscle Activity During Agonist Muscle Contraction. The Journal of Pain, Volume 12, Issue 12, December 2011, Pages 1282–1288
- John V. Basmajian, Carlo J. De Luca. Muscles Alive: Their Function Revealed by ElectroMyography. 1985
- Robert Schleip, Thomas W. Findley, Leon Chaitow, Peter A. Huijing. Fascia: The Tensional Network of the Human Body © 2012 Elsevier Ltd.
- Sakoma Y, Sano H, Shinozaki N, et al. (2011). Anatomical and functional segments of the deltoid muscle. J. Anat. 218: 185-190.
- Gurushantappa PK, Kuppasad S. (2015). Anatomy of the axillary nerve and its clinical importance: a cadaveric study. Journal of Clinical and Diagnostic Research. 9(3): AC13-AC17
- Wysiadecki G, Polguj M, Zytowski A, et al. (2014). Morphology and proposed model of innervation of the human deltoid muscle: a pilot study. Folia Morphol. 73(2): 216-223.
- Johnson, M. A., Polgar, J., Weightman, D., & Appleton, D. (1973). Data on the distribution of fibre types in thirty-six human muscles: an autopsy study. Journal of the Neurological Sciences, 18(1), 111-129
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