- The articular portion of the tendon as it exits the
shoulder and enters the intertuberal groove may
develop tendinosis due to repetitive humeral move-
ments, friction below the subacromial arch, and com-
promised blood supply. - Instability of the long head of the biceps may occur
when capsular ligaments or rotator cuff tendons are
disrupted. Clicking as the humerus is rotated may
reproduce these findings in a painful shoulder.
•Tendonopathies and instability of the biceps are most
often associated with additional injuries of the shoul-
der. Rotator cuff pathology and impingement syn-
dromes are common coexistent pathologies.
BICEPS ANATOMY
- The biceps has two proximal origins and inserts below
the elbow on the tubercle of the proximal radius. It
traverses both the shoulder and the elbow and plays a
role in shoulder flexion, elbow flexion, and forearm
supination. From a shoulder perspective, the long
head of the biceps is the most susceptible to injury.
The short head originates from the coracoid process
and is rarely injured. - The musculocutaneous nerve (C5, C6, C7) innervates
the biceps. The nerve can be seen to enter the short
head inferior to the coracoid. The second portion is
innervated more distally, prior to this nerve becoming
a cutaneous nerve along the anterolateral aspect of the
forearm. Injury to this nerve can result from anterior
shoulder instability and surgical retractors. - The long head of the biceps originates from the gle-
noid tubercle and superior labrum (Habermeyer and
Walch, 1996). This tendon changes direction as it
exits the shoulder. Capsular ligaments act as a pulley
as the tendon exits the articular space and traverses
under the transverse ligament (Paavolainen, Slatis,
and Aalto, 1984). Extra-articularly, it runs within a
groove between the greater and lesser tuberosities.
The muscle tendon junction is adjacent to the inferior
border of the pectoralis major tendon. Anatomic vari-
ations including attachments to the rotator cuff and
absence of glenoid attachment may be rarely found
without consequence. - Biceps pathology involving the elbow will be dis-
cussed in the appropriate section.
BICEPS FUNCTION
- The biceps functions during arm elevation, flexes and
supinates the elbow. Shoulder function includes assist
in arm elevation, stabilizing or depressing the humeral
head, while the arm is externally rotated (Burkhead, Jr
et al, 1998).- Due to two proximal attachment sites, the long head
may rupture and not severely impact these functions if
the rotator cuff or short head attachments can compen-
sate for this tear (Mariani, Cofield, and Askew, 1988). - During the throwing motion, the biceps is positioned
with the arm in abduction, extended and externally
rotated. A complex change in pull occurs as the shoul-
der changes from cocking to acceleration (Glousman
et al, 1988). In addition to shoulder stresses, elbow
extension occurs simultaneously placing additional
eccentric tension on the proximal anatomy (Andrews,
Carson, Jr, and McLeod, 1985; Abrams, 1991).
BICEPS PATHOLOGIC CONDITIONS- Shoulder biceps tears can be located adjacent to the
superior labrum, along the articular portion, beneath
the transverse ligament, within the groove, or at the
muscle tendon junction. - Biceps tendinosis is most commonly located adjacent
to the location where the tendon has a directional
change as it exits the shoulder. Since the shoulder
abducts and adducts, these tears extend proximally
and can be seen arthroscopically during the articular
exam (Curtis and Snyder, 1993). - Biceps tendon subluxation can occur when the sup-
porting capsular ligaments are disrupted. This can
occur when the superior portion of the subscapularis
is detached from the lesser tuberosity (Peterson,
1986). Capsular and coracohumeral ligament injury
can allow medial subluxation without significant
tendon tear (Paavolainen, Slatis, and Aalto, 1984;
Walch et al, 1998).
•Tears at the muscle tendon junction can result from
traumatic events. Abrupt eccentric contraction may
create a tear (Garrett, Jr et al, 1987). Exclusion of a
pectoralis major tear is important since there is over-
lap in the clinical exam.
•Biceps long head tendinosis can be coexistent with
rotator cuff pathology in the impingement syndrome
(Neer, Bigliani, and Hawkins, 1977). The tendon is
aligned along the leading edge of the supraspinatus.
During forward flexion, these structures can contact the
anterior acromion and the coracoacromial ligament.
BICEPS COMPLAINTS AND FINDINGS- The most common complaint is pain along the antero-
medial aspect of the shoulder. Some patients can
demonstrate a click with rotation of the humerus.
284 SECTION 4 • MUSCULOSKELETAL PROBLEMS IN THE ATHLETE