A detailed discussion concerning the activation of TrPs in this muscle is given in Chapter 12, but attention must be drawn here to the fact that any in the clavicular section of this muscle may be responsible for pain in the front of the shoulder, and may also cause abduction of the arm at the shoulder joint to be restricted (see Fig. 12.6).
CORACOBRACHIALIS (see Fig. 12.9) This muscle, together with the pectoralis minor and the short head of the biceps, is attached at its upper end to the coracoid process, and at its lower end to the middle of the humerus.
TrP activity in it usually does not become evi- dent until TrPs in other shoulder muscles, particu- larly the anterior deltoid, have first been success fully deactivated. As Travell & Simons (1983, p. 440) have pointed out, TrP activity in this muscle should be suspected when despite deactivating TrPs in neighbouring muscles the patient continues to complain of pain over the anterior deltoid region, and down the back of the arm to the dor- sum of the hand, but sparing for some reason the elbow and wrist (Fig. 13.11). TrPs in this muscle are usually to be found in in the upper part of it deep to the anterior deltoid (Fig. 13.11).
In order to deactivate TrPs in this muscle the patient should be placed in the supine position with the arm externally rotated.
TRICEPS (LONG HEAD) A detailed account of the various parts of the triceps muscle and their patterns
Figure 13.6 To illustrate how a normal person on putting the arm behind the back can reach across to rest the back of the hand on the opposite arm. With trigger points in either the anterior deltoid or coracobrachialis muscle it is usually not possible to reach past the midline.
Figure 13.7 The pattern of pain referral from a trigger point in the posterior part of the deltoid muscle.
Figure 13.8 To illustrate the usual location of trigger points in the upper anterior part and lower posterior part of the deltoid muscle.
Figure 13.9 To show the usual location of trigger points in the lower part of the biceps muscle just above the elbow.
of TrP pain referral will be given when discussing pain around the elbow joint in Chapter 15. Reference, however, must be made here to the long head of this muscle (Fig. 13.12) because when TrP activity develops in the posterior part of the deltoid it may also arise in this and in the latis- simus dorsi and the teres major. TrPs in the long head cause pain to be referred upwards over the back of the arm to the posterior part of the shoul- der and sometimes downwards along the back of the forearm (Fig. 13.13).
A person with TrP activity in this muscle, when instructed to raise both arms above the head with the elbows straight and palms to the front, finds it impossible to hold the arm on the affected side tight against the side of the head (Fig. 13.14).
TrP examination TrPs when present are usually to be found in the mid third of the long head (Fig 13.13).
TrP deactivation A detailed discussion of this will be given in Chapter 15.
LATISSIMUS DORSI AND TERES MAJOR (see Fig. 12.14)
These muscles, which together form the posterior axillary fold, often have TrP activity in them at the same time.
Figure 13.11 The pattern of pain referral from a trigger point or points (䉱) in the coracobrachialis muscle.
Figure 13.10 The pattern of pain referral from trigger points (䉱) in the lower part of the biceps muscle.
TrP activity in the latissimus dorsi muscle has already been discussed in Chapter 12 as it mainly causes pain to be felt in the chest wall around the inferior angle of the scapula. The pain, however, may also be referred to the back of the shoulder and down the inner side of the arm (see Fig. 12.15).
Teres major is attached medially to the lower part of the scapula; and laterally converges with the latissimus dorsi muscle to form the posterior axillary fold before being inserted into the tuberosity close to the latissimus dorsi in the bicip- ital groove (see Fig. 12.14). TrP activity in it causes pain to be felt in the posterior part of the shoulder when reaching forwards and upwards and occa- sionally along the back of the forearm (Fig. 13.15). A person with TrP activity in this muscle has difficulty in pressing the raised outstretched arm tightly against the side of the head in the same way as someone with TrP activity in the long head of the triceps does. (Fig. 13.14).
TrP examination TrPs are liable to be found both at the inner and outer ends of the muscle (Fig. 13.16). Those present medially at the insertion of the muscle into the lower lateral border of the
Greater tuberosity
Teres minor Humerus Long head of triceps Lateral head of triceps Latissimus dorsi Olecranon Teres major Infraspinatus Triangular space Quadrangular space Deltoid Spine of scapula Supraspinatus
Figure 13.12 The dorsal scapular muscles and triceps. Left side. The spine of the scapula has been divided near its lateral end and the acromion has been removed together with a large part of the deltoid.
Figure 13.13 The pattern of pain referral from a trigger point or points (䉱) in the long head of the triceps muscle.
scapula may be located by applying pressure against the underlying scapula. Those occurring laterally in the posterior axillary fold may be located by gripping the fold between the thumb and fingers but my preference is to use flat palpa- tion (see Ch. 7). This may be done with the patient sitting but is easier to do with the patient lying supine and the arm abducted to 90°.
Deactivation of TrPs TrPs in the vicinity of where this muscle inserts into the scapula are most readily deactivated with the patient lying on the contralateral side. TrPs in the posterior axillary fold should be deactivated with the patient lying in the supine position and the arm abducted at a right angle.
SUBSCAPULARIS MUSCLE It is important not to overlook TrPs hidden away in the subscapularis muscle in anyone with persistent pain in the shoulder (Fig. 13.17).
Activation of TrPs TrPs are liable to become active in this muscle when repeated movements involving a considerable amount of internal rota- tion are carried out. Also, as a result of direct
Figure 13.14 To illustrate the difficulty experienced in bringing the ipsilateral arm up against the ear when there is trigger point activity in either the long head of the triceps or the teres major muscle.
Figure 13.15 The pattern of pain referral from a trigger point at the inner end of the teres major muscle.
Figure 13.16 To show sites at which trigger points are liable to become activated in the teres major muscle.