Shoulder:The Biceps Tendon/Long Head of the Biceps - Revision history

Alexandre.laedermann at 12:57, 13 July 2021

2021-07-13T12:57:51Z

Alexandre.laedermann at 12:17, 13 July 2021

2021-07-13T12:17:42Z

Alexandre.laedermann: Anecdote added

2020-02-11T16:33:01Z

Anecdote added

Alexandre.laedermann at 16:25, 11 February 2020

2020-02-11T16:25:24Z

Alexandre.laedermann: Created page with "Proximal Biceps Disorders The proximal biceps comprises the short head of biceps and the long head of biceps. The short head of has a muscular and aponeurotic origin from t..."

2020-01-27T20:54:49Z

Created page with "Proximal Biceps Disorders The proximal biceps comprises the short head of biceps and the long head of biceps. The short head of has a muscular and aponeurotic origin from t..."

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Proximal Biceps Disorders

The proximal biceps comprises the short head of biceps and the long head of biceps. The short head of has a muscular and aponeurotic origin from the coracoid. Ruptures of the short head of biceps are incredibly rare and unusual. However, the long head of biceps (LHB) which arises from the superior labrum at the supraglenoid tubercle has a long tendinous portion which traverses a substantive route within the shoulder and then extra-articular before joining the musculo-tendinous junction at the level of the humeral neck. The formation of the LHB in taking this tenuous course is an evolutionary phenomenon as humans have evolved from walking on all fours to an upright stance, using their shoulders for manipulation and overhead tasks as opposed to ambulation.
As the LHB traverses from intra-articular to extra-articular it is contained within the biceps groove between the lesser and greater tuberosities by the biceps pulley (deep) and by the transverse ligament (superficial).
The biceps pulley is a key stabiliser to the biceps and is made up by the superior glenohumeral ligament and coracohumeral ligament, both being intricately associated the subscapularis tendon and the supraspinatus tendon. The biceps pulley can be easily appreciated and visualised arthroscopically, as well as during open dissection.

Biceps pulley seen at arthroscopy

FUNCTION OF THE LONG HEAD OF BICEPS

Flexor: This role of the long head of biceps in the shoulder has been open to some controversy. It has been shown to be a minor flexor providing 7% of shoulder flexion.
Depressor: It has a weak depression effect in association with the intact cuff depressing the humeral head.
Stabiliser: LHB acts as a stabiliser for the glenohumeral joint only in the absence of all the other dynamic and static stabilisers to the joint. It provides an equal amount of stability as the short head of biceps. (Itoi, 1993)
Throwing: The LHB appears to be predominantly active during the overhead throwing action. It is active only during this stage of elbow flexion and most active during deceleration of the elbow (Andrews, 1985).

LHB PATHOLOGIES
Conditions affecting the long head of biceps are:

Tendonitis.
Rupture.
Biceps instability (subluxation or dislocation)
The causes of biceps instability are due to:
A pulley rupture
Rotator cuff tear (subscapularis)
Fracture mal-union on non-union

DIAGNOSING LHB PATHOLOGY

Proximal biceps pain is mainly felt by the patient with any lifting activities, overhead sports activities - those activities particularly relating to lifting in the frontal plane with the elbow flexed, such as putting a box on one shoulder or also playing overhead sports such as tennis. The pain is well localised and very specific to the anterior aspect of the shoulder, in line with the long head of biceps tendon.

The clinical features are:

Anterior shoulder pain
Localised tenderness specifically over the biceps groove and proximal biceps
Speeds test, which has an 80% sensitivity
Yergasons test, which has a 50% sensitivity
AERS test (abduction, external rotation, supination)
A LHB rupture is denoted by a typical 'popeye sign' with a dropped biceps muscle. The retracted muscle may be fixed or mobile. In my experience patients with a mobile (unfixed) ruptured biceps tend to suffer with discomfort, cramping and aching from the biceps muscle with activities.

Popeye sign

INVESTIGATIONS

X-rays may be beneficial, particularly the axillary view showing osteophytes or malunion and bony abnormalities in the region of the biceps groove.
Ultrasound scan is particularly helpful for demonstrating fluid around the long head of biceps dynamically assessing the stability of the biceps with internal and external rotation of the arm and also assessing the integrity of the subscapularis tendon. Abnormalities of the bone in the biceps groove can also be seen, in particular osteophytes and degenerative changes, as well as fractures and fracture mal-unions. Dislocated LHB tendon can also be clearly seen. The absence of the biceps tendon in the groove and the retracted muscle can be seen in the case of a complete LHB rupture.
Modern ultrasound scanners are also able to demonstrate intra-substance tears and tendonosis of the biceps tendon. (Armstrong, 2006). An ultrasound scan by a skilled clinician is much more beneficial for LHB pathology than MRI scans.
Arthroscopic examination is the best form of imaging for the biceps origin and superior labrum for SLAP tears the intra-articular long head of biceps is easily visualised and 1cm of the extra-articular biceps can be pulled into the joint to assess a part of the extra-articular biceps. The subscapularis, supraspinatus and biceps pulley can all be best visualised arthroscopically and also dynamically assessed.

Ultrasound scans showing biceps tendonitis on the left (fluid in the biceps sheath) and a dislocated LHB on the right (arrow)

Pulley tear at arthroscopy in an overhead athlete

TREATMENT

1. Physiotherapy:
Functional biceps tendonitis can occur with glenohumeral instability, as well as scapula disorders. Instability and protraction of the shoulders leads to tension on the long head of biceps tendon. This can be addressed by postural correction and a scapula setting and stabilising regime.

2. Injections:
Injections into the biceps tendon sheath are beneficial to reduce inflammation and swelling of the biceps sheath. However it is essentially that these be performed under ultrasound guidance and my personal preference is towards Hyaluronan injections rather than corticosteroids due to the proteolytic natures of steroids and risk of rupture with corticosteroids.

3. Surgery:

Pulley lesions are predominantly an injury of the overhead athlete and is a rare injury being a diagnosis of exclusion. Pulley lesions can in these circumstances be repaired arthroscopically.
Biceps Tendonitis is treated either with a biceps tenotomy or Biceps tenodesis . A number of authors have published on the role of tenotomy versus tenodesis (Mariani et al, 1988; Koenig, 2004; Walch, 2005; Wolf, 2005; Osbhar, 2002; Kelly, 2005; Robert, 2005; Franceschi, 2006; Duff & Campbell, 2012). Long head of biceps tenotomy is a good treatment for biceps tendonitis but should be reserved to elderly and low demand patients only as the resulting popeye deformity and possible cramping of the muscle are a common problem in high demand and athletic patients. Biceps tenodesis is indicated for more active and higher demand patients. This can be performed as an arthroscopically assisted procedure with good strong fixation and early return to manual activities and sports.
LHB ruptures: Most LHB ruptures cause very little symptoms and do not require treatment. However high demand manual patients and athletic patients with a mobile and stable long head of biceps rupture do often complain of cramping and aching of the biceps muscle. In these circumstances a subpectoral biceps tenodesis is of benefit (Mariani, 1988, Ng & Funk, 2012).

@@ Line 43: / Line 43: @@
 Throwing: The LHB appears to be predominantly active during the overhead throwing action. It is active only during this stage of elbow flexion and most active during deceleration of the elbow (''Andrews, 1985'').
-== Pathologies of the Long Head of Biceps ==
+==Pathologies of the Long Head of Biceps==
 Conditions affecting the long head of biceps are:
-* Tendonitis.
+*Tendonitis.
-* Rupture.
+*Rupture.
-* Biceps instability (subluxation or dislocation). The causes of biceps instability are a pulley rupture, a rotator cuff tear (subscapularis) and fracture mal-union on non-union.
+*Biceps instability (subluxation or dislocation). The causes of biceps instability are a pulley rupture, a rotator cuff tear (subscapularis) and fracture mal-union on non-union.
-== Diagnosis of LHB Pathology ==
+==Diagnosis of LHB Pathology==
 Proximal biceps pain is mainly felt by the patient with any lifting activities or overhead sports activities - activities particularly relating to lifting in the frontal plane with the elbow flexed, such as putting a box on one shoulder or also playing overhead sports such as tennis. The pain is well localised and very specific to the anterior aspect of the shoulder, in line with the long head of biceps tendon.
 The clinical features are:
-Anterior shoulder pain
+* Anterior shoulder pain
-Localised tenderness specifically over the biceps groove and proximal biceps
+* Localised tenderness specifically over the biceps groove and proximal biceps
-Speeds test, which has an 80% sensitivity
+* Speeds test, which has an 80% sensitivity
-Yergasons test, which has a 50% sensitivity
+* Yergasons test, which has a 50% sensitivity
-AERS test (abduction, external rotation, supination)
+* AERS test (abduction, external rotation, supination)
-Popeye sign
+A LHB rupture is denoted by a typical 'popeye sign' with a dropped biceps muscle. The retracted muscle may be fixed or mobile. In my experience patients with a mobile (unfixed) ruptured biceps tend to suffer with discomfort, cramping and aching from the biceps muscle with activities.
-INVESTIGATIONS
+''Popeye sign''
 X-rays may be beneficial, particularly the axillary view showing osteophytes or malunion and bony abnormalities in the region of the  biceps groove.
-Ultrasound scan is particularly helpful for demonstrating fluid around the long head of biceps dynamically assessing the stability of the biceps with internal and external rotation of the arm and also assessing the integrity of the subscapularis tendon.  Abnormalities of the bone in the biceps groove can also be seen, in particular osteophytes and degenerative changes, as well as fractures and fracture mal-unions.  Dislocated LHB tendon can also be clearly seen. The absence of the biceps tendon in the groove and the retracted muscle can be seen in the case of a complete LHB rupture.
-Modern ultrasound scanners are also able to demonstrate intra-substance tears and tendonosis of the biceps tendon. (Armstrong, 2006). An ultrasound scan by a skilled clinician is much more beneficial for LHB pathology than MRI scans.
+Ultrasound scan is particularly helpful to demonstrate fluid around the long head of biceps dynamically assessing the stability of the biceps with internal and external rotation of the arm and also assessing the integrity of the subscapularis tendon. Abnormalities of the bone in the biceps groove can also be seen, in particular osteophytes and degenerative changes, as well as fractures and fracture mal-unions.  Dislocated LHB tendon can also be clearly seen. The absence of the biceps tendon in the groove and the retracted muscle can be seen in the case of a complete LHB rupture.
-Arthroscopic examination is the best form of imaging for the biceps origin and superior labrum for SLAP tears the intra-articular long head of biceps is easily visualised and 1cm of the extra-articular biceps can be pulled into the joint to assess a part of the extra-articular biceps.  The subscapularis, supraspinatus and biceps pulley can all be best visualised arthroscopically and also dynamically assessed.
+Modern ultrasound scanners are also able to demonstrate intra-substance tears and tendonosis of the biceps tendon (''Armstrong, 2006''). An ultrasound scan by a skilled clinician is much more beneficial for LHB pathology than MRI scans.
-Ultrasound scans showing biceps tendonitis on the left (fluid in the biceps sheath) and a dislocated LHB on the right (arrow)
+''Ultrasound scans showing biceps tendonitis on the left (fluid in the biceps sheath) and a dislocated LHB on the right (arrow)''
-Pulley tear at arthroscopy in an overhead athlete
+''Pulley tear at arthroscopy in an overhead athlete''
-TREATMENT
+== Treatment ==
-.    Physiotherapy:
+Functional biceps tendonitis can occur with glenohumeral instability as well as scapula disorders. Instability and protraction of the shoulders leads to tension on the long head of biceps tendon. This can be addressed by postural correction and a scapula setting and stabilising regime.
 .    Injections:
-Injections into the biceps tendon sheath are beneficial to reduce inflammation and swelling of the biceps sheath.  However it is essentially that these be performed under ultrasound guidance and my personal preference is towards Hyaluronan injections rather than corticosteroids due to the proteolytic natures of steroids and risk of rupture with corticosteroids.
 .    Surgery:
-Pulley lesions are predominantly an injury of the overhead athlete and is a rare injury being a diagnosis of exclusion.   Pulley lesions can in these circumstances be repaired arthroscopically.
+Pulley lesions are predominantly an injury of the overhead athlete and is a rare injury being a diagnosis of exclusion. In these circumstances pulley lesions can be repaired arthroscopically.
-Biceps Tendonitis is treated either with a biceps tenotomy or  Biceps tenodesis . A number of authors have published on the role of tenotomy versus tenodesis (Mariani et al, 1988; Koenig, 2004; Walch, 2005; Wolf, 2005; Osbhar, 2002; Kelly, 2005; Robert, 2005; Franceschi, 2006; Duff & Campbell, 2012). Long head of biceps tenotomy is a good treatment for biceps tendonitis but should be reserved to elderly and low demand patients only as the resulting popeye deformity and possible cramping of the muscle are a common problem in high demand and athletic patients.  Biceps tenodesis is indicated for more active and higher demand patients.  This can be performed as an arthroscopically assisted procedure with good strong fixation and early return to manual activities and sports.
-LHB ruptures:  Most LHB ruptures cause very little symptoms and do not require treatment.  However high demand manual patients and athletic patients with a mobile and stable long head of biceps rupture do often complain of cramping and aching of the biceps muscle.  In these circumstances a subpectoral biceps tenodesis is of benefit (Mariani, 1988, Ng & Funk, 2012).
+Biceps Tendonitis is treated either with a biceps tenotomy or Biceps tenodesis. A number of authors have published on the role of tenotomy versus tenodesis (''Mariani et al, 1988; Koenig, 2004; Walch, 2005; Wolf, 2005; Osbhar, 2002; Kelly, 2005; Robert, 2005; Franceschi, 2006; Duff & Campbell, 2012''). Long head of biceps tenotomy is a good treatment for biceps tendonitis, but should be reserved for elderly and low demand patients only, as the resulting popeye deformity and possible cramping of the muscle are a common problem in high demand and athletic patients. Biceps tenodesis is indicated for more active and higher demand patients. This can be performed as an arthroscopically assisted procedure with a good strong fixation and early return to manual activities and sports.

@@ Line 7: / Line 7: @@
 <br />
-== Anecdote ==
+==Anecdote==
 (unpublished data, courtesy of Dr. Wayne Z Burkhead (Buz))
-It was the first day of my fellowship with Dr. Charles Rockwood in 1983. I had pretty much created the fellowship. I knew I wanted extra training in the shoulder and had asked him if I could come for 3 months.  He thought about it for several days, then said I could come; but I had to come for six months, and he had no money to pay me, so I’d have to work for free. Earlier in the year I had been diagnosed with a level III melanoma and had surgery for it. At that time the prognosis was 67% five-year survival. I wasn’t crazy about spending six months of what might be a shortened life working for free but,  I did love the shoulder and decided to go ahead and accept the offer.
+It was the first day of my fellowship with Dr. Charles Rockwood in 1983. I had pretty much created the fellowship. I knew I wanted extra training in the shoulder and had asked him if I could come for 3 months. He thought about it for several days, then said I could come; but I had to come for six months, and he had no money to pay me, so I’d have to work for free. Earlier in the year I had been diagnosed with a level III melanoma and had surgery for it. At that time the prognosis was 67% five-year survival. I wasn’t crazy about spending six months of what might be a shortened life working for free, but I did love the shoulder and decided to go ahead and accept the offer.
-We had a shoulder Clinic at the VA hospital. I had seen a patient earlier in the day that he had operated on and performed an acromioplasty. The patient had persistent anterior shoulder pain in the region of his biceps tendon. In the clinic I had injected this area with local anesthetic and completely relieved his pain. I had reviewed the worlds literature on the shoulder which at that time was very small. One article the, The four in one procedure written by the Neviasers published in CORR in 1982 described The treatment for failed  impingement surgery with revision acromioplasty  CA ligament excision, distal clavicle excision,  and biceps tenodesis. Thus, the four in one.
+We had a shoulder Clinic at the VA hospital. I had seen a patient earlier in the day that he had operated on and performed an acromioplasty. The patient had persistent anterior shoulder pain in the region of his biceps tendon. In the clinic I had injected this area with local anesthetic and completely relieved his pain. I had reviewed the worlds literature on the shoulder which at that time was very small. One article ''"The four in one procedure"'' written by the Neviasers and published in CORR in 1982 described the treatment for failed impingement surgery with revision acromioplasty, CA ligament excision, distal clavicle excision, and biceps tenodesis. Thus, the four in one.
-I presented the case and suggested the patient be re-operated and have a four and one.
+I presented the case and suggested the patient to be re-operated and have a four and one.
-All Dr. Charles Rockwood heard was biceps tendinitis. This is what he said. “Biceps tendinitis, biceps tendinitis, Charlie Neer has never seen biceps tendinitis Frank Jobe has never seen biceps tendinitis; I’ve  Been chairman of this department for 20 years and I’ve never seen biceps tendinitis. You’ve been here from Dallas for 24 hours and you’ve got a case of biceps tendinitis. Let me tell you what I do to smart asses like you. Leonard Goldner Keeps a slot in the dermatology residency program at Duke university for people like you I want you to go home I’m gonna put you on a Greyhound bus and send you to Durham North Carolina you are not going to be an orthopedic surgeon Dr. Burkhead you are going to be a pimple popper”
+All Dr. Charles Rockwood heard was biceps tendinitis. This is what he said. “Biceps tendinitis, biceps tendinitis, Charlie Neer has never seen biceps tendinitis, Frank Jobe has never seen biceps tendinitis; I’ve been a chairman of this department for 20 years and I’ve never seen biceps tendinitis. You’ve been here from Dallas for 24 hours and you’ve got a case of biceps tendinitis. Let me tell you, what I do to smart asses like you. Leonard Goldner Keeps a slot in the dermatology residency program at Duke university for people like you. I want you to go home, I’m gonna put you on a Greyhound bus and send you to Durham North Carolina, you are not going to be an orthopedic surgeon. Dr. Burkhead, you are going to be a pimple popper”
-I can hear his voice distinctly today in my mind as I could 37 years ago. He was president of the American Academy of orthopedic surgeons I thought maybe he could end my career and that I would have to go on a Greyhound to Duke. But, He was just f....ing with me and asserting his authority. He let me stay; he called me Biceps Buzzy, and every time we got close to the biceps in surgery he would tell everybody to watch my hands to make sure that I didn’t cut the biceps. For my sins he assigned me the chapter on the biceps tendon in the landmark textbook The Shoulder. In  one of the later editions, I tell the story and at the end of the chapter I say and you know what Dr. Rockwood that patient probably still has biceps tendinitis today.
+I can hear his voice distinctly today in my mind as I could 37 years ago. He was a president of the American Academy of orthopedic surgeons, I thought maybe he could end my career and that I would have to go on a Greyhound to Duke. But, He was just f....ing with me and asserting his authority. He let me stay; he called me Biceps Buzzy, and every time we got close to the biceps in surgery, he would tell everybody to watch my hands to make sure that I didn’t cut the biceps. For my sins he assigned me the chapter on the biceps tendon in the landmark textbook The Shoulder. In one of the later editions, I tell the story and at the end of the chapter I say and you know what, Dr. Rockwood, that patient probably still has biceps tendinitis today.
-While it is recognized today that the biceps tendon is a pain generator in the shoulder, in the 70s and 60s biceps tenodesis was the most common operation for shoulder pain there were some patients who did not get well because they had unrecognized subacromial impingement. This is the mindset that Dr. Rockwood was coming from. Charles Neer who was the leading thought leader at the time taught dogmatically that all biceps problems are related to the acromial spur and would go away with the acromioplasty.
+While it is recognized today that the biceps tendon is a pain generator in the shoulder, in the 70s and 60s biceps tenodesis was the most common operation for shoulder pain, there were some patients who did not get well, because they had unrecognized subacromial impingement. This is the mindset that Dr. Rockwood was coming from. Charles Neer, who was the leading thought leader at the time, taught dogmatically that all biceps problems are related to the acromial spur and would go away with the acromioplasty.
-Unfortunately there is a herd mentality among orthopedic surgeons when it comes to solving problems. Often times these herds follow blindly the thought leader down paths that are incorrect. examples of this are the acromioplasty, the slap lesion, reverse shoulder arthroplasty and, today ironically,  biceps tenodesis is probably over performed. It is extremely important for the shoulder surgeon to understand each of the pain generators in any individual patient and address those surgically if they did not respond to conservative treatment.
+Unfortunately, there is a herd mentality among orthopedic surgeons when it comes to solving problems. Often times these herds follow blindly the thought leader down paths that are incorrect. Examples of this are the acromioplasty, the slap lesion, reverse shoulder arthroplasty and, today ironically biceps tenodesis is probably over performed. It is extremely important for the shoulder surgeon to understand each of the pain generators in any individual patient and address those surgically, if they did not respond to conservative treatment.
-I  Returned to Dallas Texas and I’ve been in private practice my entire career I built my reputation early on revising  patients with persistant pain after Acromioplasty with Revision acromioplasty ca ligament excision distal clavicle excision and biceps tenodesis. Instead of the 4 in one  i refer to it as the RAMPAGE procedure. Removal All major pain generators.
+I returned to Dallas Texas and I’ve been in private practice my entire career I built my reputation early on revising patients with persistant pain after Acromioplasty with Revision acromioplasty, CA ligament excision, distal clavicle excision and biceps tenodesis. Instead of the 4 in one I refer to it as the RAMPAGE procedure (Removal All Major Pain Generators).
-Spend time with your patients let them talk to you. They will usually tell you whats wrong with them and how they want to be treated. Dont follow the herd.
+Spend time with your patients let them talk to you. They will usually tell you what's wrong with them and how they want to be treated. Don't follow the herd.
-==Anatomical Considerations==
+==Function of the Long Head of Biceps==
-Biceps pulley seen at arthroscopy
+Flexor: This role of the long head of biceps in the shoulder has been open to some controversy.  It has been shown to be a minor flexor providing 7% of shoulder flexion.
-<br />
+Depressor: It has a weak depression effect in association with the intact cuff depressing the humeral head.
-==Fonction of the Long Head of Biceps==
+Stabiliser: LHB acts as a stabiliser for the glenohumeral joint only in the absence of all the other dynamic and static stabilisers to the joint. It provides an equal amount of stability as the short head of biceps (''Itoi, 1993'').
-Flexor: This role of the long head of biceps in the shoulder has been open to some controversy.  It has been shown to be a minor flexor providing 7% of shoulder flexion.
+Throwing: The LHB appears to be predominantly active during the overhead throwing action. It is active only during this stage of elbow flexion and most active during deceleration of the elbow (''Andrews, 1985'').
-LHB PATHOLOGIES
+== Pathologies of the Long Head of Biceps ==
 Conditions affecting the long head of biceps are:
-Tendonitis.
+* Tendonitis.
-Rupture.
+* Rupture.
-Biceps instability (subluxation or dislocation)
+* Biceps instability (subluxation or dislocation). The causes of biceps instability are a pulley rupture, a rotator cuff tear (subscapularis) and fracture mal-union on non-union.
-Proximal biceps pain is mainly felt by the patient with any lifting activities, overhead sports activities - those activities particularly relating to lifting in the frontal plane with the elbow flexed, such as putting a box on one shoulder or also playing overhead sports such as tennis.  The pain is well localised and very specific to the anterior aspect of the shoulder, in line with the long head of biceps tendon.
+== Diagnosis of LHB Pathology ==
 The clinical features are:

@@ Line 1: / Line 1: @@
 <br />
-== Bullet Points ==
+==Bullet Points==
 <br />
-== Key Words ==
+==Key Words==
-== Anatomical Considerations ==
+I presented the case and suggested the patient be re-operated and have a four and one.
 The proximal biceps comprises the short head of biceps and the long head of biceps.  The short head of has a muscular and aponeurotic origin from the coracoid.  Ruptures of the short head of biceps are incredibly rare and unusual.  However, the long head of biceps (LHB) which arises from the superior labrum at the supraglenoid tubercle has a long tendinous portion which traverses a substantive route within the shoulder and then extra-articular before joining the musculo-tendinous junction at the level of the humeral neck.  The formation of the LHB in taking this tenuous course is an evolutionary phenomenon as humans have evolved from walking on all fours to an upright stance, using their shoulders for manipulation and overhead tasks as opposed to ambulation.
 As the LHB traverses from intra-articular to extra-articular it is contained within the biceps groove between the lesser and greater tuberosities by the biceps pulley (deep) and by the transverse ligament (superficial).
@@ Line 16: / Line 38: @@
 <br />
-== Fonction of the Long Head of Biceps ==
+==Fonction of the Long Head of Biceps==
 Flexor: This role of the long head of biceps in the shoulder has been open to some controversy.  It has been shown to be a minor flexor providing 7% of shoulder flexion.
 Depressor: It has a weak depression effect in association with the intact cuff depressing the humeral head.
 Stabiliser: LHB acts as a stabiliser for the glenohumeral joint only in the absence of all the other dynamic and static stabilisers to the joint.  It provides an equal amount of stability as the short head of biceps. (Itoi, 1993)
 Throwing: The LHB appears to be predominantly active during the overhead throwing action.  It is active only during this stage of elbow flexion and most active during deceleration of the elbow (Andrews, 1985).
 LHB PATHOLOGIES