Distal triceps tendon

Function

What the tendon joins

The triceps brachii is the muscle on the back of the upper arm, and it has three parts called heads⁷. It has long been described as a long, a lateral (outer) and a medial (inner) head that merge into one attachment on the olecranon⁷. The olecranon is the bony point of the elbow. Together with the small anconeus muscle, the triceps is what straightens the elbow⁸. A tendon joins muscle to bone, and the distal triceps tendon is where the triceps attaches at the elbow¹.

The three heads start in different places¹:

Head	Where it starts
Long	The infraglenoid tubercle, a small raised area on the scapula (shoulder blade)¹
Lateral	The outer back of the humerus (upper arm bone), above the spiral groove, a channel in the bone¹
Medial	The back of the humerus, below that groove¹

Engraving of the left shoulder blade and upper arm from behind. The long and lateral heads of the triceps brachii run down the back of the humerus and join a broad tendon that attaches to the olecranon at the point of the elbow. Supraspinatus, infraspinatus, teres minor and teres major sit on the shoulder blade. — Triceps and the muscles on the back of the shoulder bladeHenry Vandyke Carter, in Henry Gray, Anatomy of the Human Body (1918), Fig. 412. Public domain, via Wikimedia Commons. (source, Public domain)

How it attaches to the elbow

A systematic review describes the attachment as a two-layered tendon spread over a wide area of the olecranon tip¹. In 22 elbows from donors, the attachment was shaped like a crescent⁹. A central tendon sat in the middle, with muscle extending onto the bone on each side⁹.

A dissection of five donor arms, taken from matched pairs, found three separate attachment areas on the olecranon⁷:

The back of the elbow joint’s capsule, the sleeve around the joint⁷.
A deep, fleshy part formed by the medial head⁷.
A surface, tendon-like part formed by the long and lateral heads⁷.

A review reports that the layout varies between people¹. In about half of the donor arms dissected, the medial head had its own tendon part, lying under the other two heads¹. In the other half, the heads shared one tendon, with the medial fibres still deepest¹.

Arm position seems to change which head does most of the work¹⁰. Ten healthy people straightened the elbow with the arm held at five different angles¹⁰. With the arm at the side, a computer model estimated more force and activity from the long head than from the other two¹⁰. With the arm raised to shoulder height or higher, the medial head had the highest estimated force¹⁰.

What loading studies actually measure

The studies below did not measure the force inside the tendon itself^2,3,4. Some recorded electromyography (EMG), which measures a muscle’s activity by picking up its electrical signals^4,11. Others worked out joint moments, the turning effect of a load around the elbow^2,3. On this page, more EMG activity or a larger moment is not read as a known tendon load.

Grip width changes the turning effect at the elbow in two pressing lifts^2,3:

Lift	Who was studied	What changed with grip width
Bench press	14 trained men, at their maximum	A narrow grip gave a larger moment bending the elbow early in the lift²
Seated shoulder press	11 resistance-trained men	Wider grips lowered the net moments at the elbow³

In the bench press study, the authors state that straightening the elbow is one way lifters resist that bending moment². In the shoulder press study, narrower grips also let the men lift more and move the elbow through a larger range³. A computer model of both lifts found that the elbow straighteners did little early on but took over near full extension¹².

Breakdown

Partial and complete tears

A tear can go part of the way through the tendon or right through it¹³. Among 801 elbow MRI (magnetic resonance imaging) scans taken over 15 years, 28 people had triceps tendon tears¹³. Partial tears were the most common, in 18 people, and 10 had complete tears¹³.

In a review of athletes whose tears were repaired, 58.5% of the reported tears were complete and 41.5% partial⁵. Where the site of a complete tear was recorded, 25 of 26 were avulsions, where the tendon pulled away from the olecranon⁵. The other one tore where muscle meets tendon⁵.

How the tendon tears

Tears are linked to eccentric load, meaning force applied while the muscle is working but being lengthened^5,14. In 21 tears among 19 American football professionals, this was the most common way the injury happened¹⁴. A review reports that tears in resistance training happen mainly while lowering the bar⁵. The lifts it names are the bench press and overhead pressing⁵.

Among athletes with repaired tears, weightlifting was the activity reported most often, at 40.7%⁵. American football came next, at 26.6%⁵.

Who tears it

At the largest university hospital in Slovakia, 23 people with the injury were seen over ten years¹⁵. The authors put the local rate at 0.46 cases per 100,000 people¹⁵. Studies of different groups agree that most people with this tear are men^1,5,13,16:

Group studied	What was found
170 tears pooled in a review	11 men to each woman¹
Pooled results in the same review	Mean age at the tear 47.5 years, from 12 to 75¹
277 athletes whose tears were repaired	96.4% men⁵
28 people with tears on elbow MRI	23 men and 5 women¹³
8,143 people with a repair in insurance claims	Mostly men, and mostly aged 40 to 59¹⁶

What often comes before a tear

Some people have elbow pain before the tendon tears^1,5. One review reports that up to a third of people with a tear may have long-standing pain at the back of the elbow¹. Tendinopathy is local pain in a tendon that comes with activities that load it. In people with earlier pain, the review reports tissue features of long-standing tendinopathy under the microscope¹. Among athletes where this was recorded, 18.7% had discomfort at the back of the elbow before the injury⁵.

Some other conditions were recorded alongside tears^5,17. Anabolic steroids are drugs related to the hormone testosterone. In 262 people who had surgery, the two most common were kidney disease, in 10%, and anabolic steroid use, in 7%¹⁷.

A corticosteroid is a drug that copies a type of hormone the body makes. Among 277 athletes, anabolic steroid use was recorded in 9, and an earlier corticosteroid injection at the back of the elbow in 8⁵. These counts describe who was studied; they do not show cause.

Recovery

What the outcome studies describe

The figures below are outcomes in the people each study followed. Most of them had the tendon repaired by surgery^5,6. They describe those groups and do not predict how any one person will recover.

Some partial tears in these studies healed without an operation¹⁴. Among 10 American football professionals with partial tears, 6 healed without surgery¹⁴.

Return to activity after repair

Reviews that pooled several studies report these rates of return after repair^5,6,17:

Group and outcome	Share who returned
262 people, back to the pre-injury level of activity	89%¹⁷
318 people, back to sport (where recorded)	93.3%⁶
318 people, back to military duty (where recorded)	95.3%⁶
318 people, back to work (where recorded)	92.6%⁶
277 athletes, back to sport (where recorded), after 5.2 months on average	93.0%⁵

Returning is not the same as returning at the same level^5,18. Among athletes where this was recorded, 63.6% went back to their earlier level of competition or higher⁵. Among professional American football players with triceps tendon tears over 14 seasons, however they were managed, 70.8% returned to play¹⁸. Of the players with triceps tears, 41.2% got back to their pre-injury level of performance¹⁸.

Strength after repair

Strength in the repaired arm was measured with isokinetic testing, where a machine holds the arm to a fixed speed¹⁹. Across 37 published cases, the repaired arm had on average 87% of the other arm’s strength¹⁹. In one group of ten, eight were tested an average of 88 months, over seven years, after surgery²⁰. Peak strength averaged 82% of the other arm, while endurance averaged 99%²⁰.

Connections

The muscles it serves

The tendon carries the pull of the three triceps heads to the olecranon⁷. The anconeus, a small muscle, shares the job of straightening the elbow⁸. In the bench press, a review describes the biceps brachii (the biceps) as a steadier and as the triceps’ opposing muscle²¹.

What studies of the bench press show

The traditional model of the bench press names three main movers²¹. They are the pectoralis major (the large chest muscle), the front deltoid (the front of the shoulder muscle) and the triceps²¹. EMG studies show how triceps activity compares and shifts:

Across 14 studies, triceps and pectoralis major activity were similar, and both were higher than front deltoid activity²¹.
A review found lifting intensity was the biggest factor, and the triceps was the muscle whose activity changed most often²¹.
In 28 men, triceps activity was lower with a wide grip than with medium or narrow grips²².
In 14 trained men, the medial head was more active with medium and narrow grips than with a wide grip².
In 12 men holding the bar still, a narrower grip raised triceps activity, though the author judged the change small²³.
In 30 trained adults, medial head activity was similar at five bench angles, from flat to steeply inclined²⁴.

What studies of the overhead press show

One EMG study calls the overhead press suited to working the triceps, because it pairs raising the arm with straightening the elbow²⁵. In 15 men pressing standing at 80% of their maximum, triceps activity was about 39% higher with a barbell than with dumbbells⁴. In 14 trained men lowering a barbell, pressing behind the neck brought higher triceps activity than pressing in front²⁶.

Push-ups and dips

Push-ups and dips also work the triceps^11,27. In 20 young men, triceps activity was higher than chest activity in standard, diamond and wide push-ups²⁷. Diamond push-ups, with the hands close together, gave the highest activity for both muscles²⁷. In 40 people, a narrow hand position also raised triceps activity compared with a wide one²⁸. In trained adults working to failure, triceps activity while rising in the push-up was lower than in a bench press loaded to match²⁹.

In 13 experienced men, 11 of whom did the ring dip, mean peak triceps activity was recorded in three kinds of dip¹¹. These are group averages, and they do not by themselves show that the dips differ:

Mean peak triceps EMG (millivolts). Bars start at zero; the table below gives each value with its source.

Dip variation	Mean peak triceps EMG
Bench dip	0.83 millivolts¹¹
Bar dip	1.04 millivolts¹¹
Ring dip	1.05 millivolts¹¹