Both muscles take origin from the humerus itself but also have an origin on the scapula; both insert on the forearm, namely, the radius and ulna respectively. Distally, both muscles are susceptible to overuse and strain, and may rupture or avulse from their insertions.
Rupture of the biceps and triceps are most commonly due to increased eccentric force through a degenerated tendon. Common proximal biceps conditions include tendonitis, subluxation and rupture of the long head of the biceps tendon, which takes origin from the supraglenoid tubercle of the scapula and is therefore primarily a shoulder muscle.
Proximal triceps disease is rare. As its name implies, the biceps Figure 1 has two proximal divisions. The long head of the biceps brachii originates from the glenoid labrum at the supraglenoid tubercle; the short head from the coracoid process. The biceps inserts at the radial tuberosity. It is supplied by the brachial artery and is innervated by the musculocutaneous nerve. The biceps flexes the elbow, but perhaps contrary to popular belief, it is not the most powerful flexor of the forearm— a role which actually belongs to the deeper brachialis muscle.
Indeed, when the forearm is in pronation the palm faces the ground , there is only a minimal contribution from the biceps brachii to elbow flexion Figure 2. In this position, the main flexor of the elbow is the brachialis, with contributions from the brachioradialis and supinator as well. The biceps brachii functions primarily as a supinator of the forearm turning the palm upwards. This action, which is aided by the supinator muscle, requires the elbow to be at least partially flexed.
If the elbow is fully extended, supination is then primarily carried out by the supinator muscle. These then blend together and insert on the olecranon process of the ulna. The triceps is an extensor muscle of the elbow joint and is an antagonist of the biceps and brachialis muscles. It can also fixate the elbow joint — that is, hold it in a fixed position — when the forearm and hand are used for fine movements.
The triceps is supplied by the deep brachial artery and posterior circumflex humeral artery and is innervated by the radial nerve. Patients with a distal biceps rupture present after experiencing a painful pop in the elbow after an eccentric force is applied — that is, as the elbow is moved from flexion into extension by an external force, with the biceps attempting to resist or slow that motion.
The triceps sit at the back of the arm. They start at the back, lower part of the shoulder and end at the elbow, where the ulna, one of the two bones of the forearm, begins. The biceps flex the arm, such as when you lift a child or box. They also help rotate your forearm, such as when you hit a forehand in tennis or turn a doorknob.
The triceps work with your back muscles, the latissimus dorsi, to extend your shoulder, such as when you do a pushup or push a door closed. Exercising these two muscles together is a common workout. Focus on the upper arm to increase your muscle definition.
This not only improves the appearance of your upper body, but also maintains your ability to lift and push things. A typical exercise for the biceps involves isolation, such a biceps curl with a dumbbell or barbell. The functions of the triceps include 2 , 3 :. The biceps and triceps are each unique in their makeup and function. One consists of two heads and is responsible for arm flexion, and the other consists of three heads and is responsible for arm extension. Like any other muscle, the biceps should be targeted in a variety of rep ranges.
Usually, 6—12 reps per set is a good place to start for most people. Generally, beginners may want to start with 2—3 working sets of biceps training per session, whereas intermediate and advanced trainees may need 4—6 sets to see growth.
The triceps are similar to the biceps in that they should be targeted in a variety of rep ranges. Anything between 6—12 reps per set is common. For beginners, 2—3 sets per session may be sufficient — though as you become more advanced, more sets are required to make progress.
Considering that the triceps are also a relatively small muscle, they can recover quickly , which is why at least 2 sessions per week will maximize muscle gains 4. The biceps and triceps are similar in their training capacity, both requiring 2 or more sessions per week for maximum growth. The triceps are best targeted with pushing or extension movements, whereas the biceps are best worked with curling movements. The triceps, on the other hand, consist of three heads, and hitting them all requires consideration.
Generally, the triceps are well-targeted with variations of the pushdown and overhead extension. Specifically, though, the medial and lateral heads are best targeted with pressing and pushdown movements, whereas the long head is worked well by overhead extension exercises.
That said, considering that the triceps are a larger muscle group, some may be able to lift more weight with these. Due to their structure and relatively small size, the biceps and triceps are prone to injury, either from acute trauma or chronic overuse.
These are the most common bicep injuries 5 , 6 :. Here are the most common tricep injuries 5 , 7 :. The biceps and triceps are somewhat injury prone due to their relatively small size and structure.
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