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Columns: Do It Right

The Prone Shoulder Full Can

The Prone “T”

Ronai, Peter M.S., RCEP, CEP, EP-C, CSCS-D, FACSM

Author Information
doi: 10.1249/FIT.0000000000000255
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EXERCISE TYPE

F1-9

The prone full can or shoulder T is a single-joint, open kinetic chain upper body exercise that activates and strengthens posterior muscles of the shoulder girdle.

BENEFITS OF THE EXERCISE

The prone full can or shoulder T, also known as horizontal abduction in external rotation, is part of an exercise series known as the prone T-Y-I-W series designed to provide dynamic stability, optimal muscle length and tension, and proper positioning of the scapula and shoulder girdle on the thorax during upper extremity activities (3,4,6,7,12). Another exercise from this series will be described in a subsequent article.

INTRODUCTION

Exercises to promote shoulder girdle stability are integral components of strength and conditioning, rehabilitation, and postrehabilitation exercise programs for clients who perform repetitive overhead motions during sports or occupational activities (3,4,6–12). Functional imbalances between the upper trapezius and the lower trapezius, middle trapezius, and the serratus anterior muscles have been associated with conditions like shoulder instability and subacromial impingement syndrome, which can cause shoulder pain and dysfunction (2–4,6–12). This article is not meant to help readers diagnose or treat shoulder pain or injuries. Clients should be free of shoulder or upper extremity injuries and related pain before performing these exercises. The onset of injury-related pain warrants termination of exercise and immediate client consultation with a physician, physical therapist, or other health care provider. Exercises within the T-Y-I-W series have been shown to elicit high muscle activation levels during electromyographic analyses and to promote favorable ratios of upper trapezius-to-lower trapezius (UT:LT) and upper trapezius-to-middle trapezius (UT:MT) muscle activation ratios (2–4,6–12).

PRIMARY MUSCLES ACTIVATED

Supraspinatus, infraspinatus, deltoid (middle and posterior fibers), trapezius (middle and lower fibers), rhomboids, and levator scapula (Figure 1.)

F2-9
Figure 1:
Shoulder girdle muscles activated.

TEACHING AND SAFETY POINTS

The prone T exercise can be performed on either a matted floor, (treatment) plinth table, or a multipurpose training bench. Plinth tables typically enable clients to place their faces within a cutout hole, which facilitates breathing and in-line stabilization of the cervical and thoracic (neck and upper back) spines (Figure 2). A small pillow placed under the top of the pelvis and hips can provide additional alignment and support to the lower back. Clients also can place their foreheads on a small hand-rolled towel and place a small pillow under their waist and hips to achieve similar alignment if they are lying prone on the floor (Figure 3). The use of the floor or a plinth table provides the shoulder girdle with additional extrinsic support and reduces the distance that the arms must be lifted from the starting position as compared with a multipurpose training bench (10,11). See Supplemental Digital Content 1, https://links.lww.com/FIT/A41. Exercise intensity can be increased by progressing from a supportive surface like the floor or treatment table to a multipurpose training bench where the arm is raised and lifted through a greater range of motion. Clients should exhale during the lifting phase and inhale during the lowering phase of each exercise. External loading should never prevent clients from performing each exercise in a controlled manner.

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Figure 2:
Prone T exercise performed on a plinth table.
F4-9
Figure 3:
Prone T exercise performed on the floor with extrinsic support.

PROPER PERFORMANCE

Starting Position

Clients should lie prone and maintain a straight-line position between their head, neck, and spine with their elbows fully extended and their glenohumeral (shoulder) joint in external rotation (thumbs are pointing up toward the ceiling). The arms hang down perpendicular to the floor if the exercise is performed on a multipurpose training bench. (The starting phase position appears in Figure 4.)

F5-9
Figure 4:
Prone T exercise starting and ending phase positions.

Upward Phase

By concentric actions of the middle and lower trapezius, rhomboids, infraspinatus, supraspinatus, and deltoid, the scapulae are actively retracted (adducted) and the upper arms are horizontally abducted to approximately 90 degrees until they are parallel with either the floor, plinth table, or training bench (2–4,10–12). The scapulae and arms are held in this position for a count of three. Clients should be cued to raise and lower their arms in a controlled manner, to not pull their upper arms behind the rib cage, to avoid swinging their arms, and to refrain from lifting their head/neck or back throughout the exercise. Positioning the arms behind the torso can increase stress on the anterior shoulder joint and lifting the head can increase stress on the neck and back (8,9,12). (The upward phase position appears in Figure 5.) See Supplemental Digital Content 2, https://links.lww.com/FIT/A42.

F6-9
Figure 5:
Prone T exercise upward phase position.

Downward Phase

The arms and scapulae return to the starting position in a controlled manner by eccentric actions of the middle and lower trapezius, rhomboids, infraspinatus, supraspinatus, and deltoid (2–4,11,12). Clients should be cued to lower the weight in a controlled manner and to avoid dropping their arms.

Exercise load and intensity selection can be based on the individual goals of each client (10). Although lighter loads and higher repetitions typically have been recommended for scapulohumeral stability exercises, results from a few studies suggest that it might not be necessary to limit the amount of weight used with these exercises if performed by healthy individuals without a history of shoulder pathology (1,5,12).

SUMMARY

The prone horizontal abduction in external rotation/full can (prone T) exercise is part of a series of exercises known as the T-Y-I-W series and is intended to improve scapulothoracic joint and glenohumeral joint muscle function and shoulder girdle stability. Exercises can be performed without external loading in clients who are either unaccustomed to doing them or are deconditioned. External resistance can be added in the form of dumbbells or cuff weights as tolerated by clients as their strength and endurance improves.

References

1. Alpert SW, Pink MM, Jobe FW, McMahon PJ, Mathiyakom W. Electromyographic analysis of deltoid and rotator cuff function under varying loads and speeds. J Shoulder Elbow Surg. 2000;9(1):47–58.
2. Cools AM, Declercq GA, Cambier DC, Mahieu NM, Witvrouw EE. Trapezius activity and intramuscular balance during isokinetic exercise in overhead athletes with impingement symptoms. Scand J Med Sci Sports. 2007;17(1):25–33.
3. Cools AM, Dewitte V, Lanszweert F, et al Rehabilitation of scapular muscle balance: which exercises to prescribe? Am J Sports Med. 2007;35(10):1744–51.
4. Cools AM, Struyf F, De Mey KF, Maenhout A, Castelein B, Cagnie B. Rehabilitation of scapular dyskinesis: from the office worker to the elite overhead athlete. Br J Sports Med. 2014;48(8):692–7.
5. Dark A, Ginn KA, Halaki M. Shoulder muscle recruitment patterns during commonly used rotator cuff exercises: an electromyographic study. Phys Ther. 2007;87(8):1039–46.
6. De Mey K, Danneels L, Cagnie B, Cools A. Scapular muscle rehabilitation exercises in overhead athletes with impingement symptoms: effect of a 6-week training program on muscle recruitment and functional outcome. Am J Sports Med. 2012;40(8):1906–15.
7. Escamilla R, Yamashiro K, Paulos L, Andrews J. Shoulder muscle activity and function in common shoulder rehabilitation exercises. Sports Med. 2009;39(8):663–85.
8. Kolber MJ, Beekhuizen KS, Cheng MSS, Hellman MA. Shoulder joint and muscle characteristics in the recreational weight training population. J Strength Cond Res. 2009;23(1):148–57.
9. Kolber MJ, Beekhuizen KS, Cheng MSS, Hellman MA. Shoulder injuries attributed to resistance training: a brief review. J Strength Cond Res. 2010;24(6):1696–704.
10. Ludewig P, Braman JP. Shoulder Impingement: biomechanical considerations in rehabilitation. Man Ther. 2011;16(1):33–9.
11. Pabian P, Kolber MJ, McCarthy JP. Postrehabilitation strength and conditioning of the shoulder: an interdisciplinary approach. Strength Cond J. 2011;33(3):42–55.
12. Reinold MM, Escamilla RF, Wilk KE. Current concepts in the scientific and clinical rationale behind exercises for glenohumeral and scapulothoracic musculature. J Orthop Sports Phys Ther. 2009;39(2):105–17.

Recommended Reading:

McCabe RA, Orishimo KF, McHugh MP, Nicholas SJ. Surface electromyographical analysis of the lower trapezius muscle during exercises performed below ninety degrees of shoulder elevation in healthy subjects. N Am J Sports Phys Ther. 2007;2(1):34–43.

Supplemental Digital Content

© 2016 American College of Sports Medicine.