Summer may be coming to an end here in glorious Blighty, although some may contest that we actually get a proper ‘summer’, but that’s no reason to put the guns into hibernation for the winter. Direct arm work may be frowned upon by the functional training brigade but, if it’s done the right way, it can help prevent against injury and give you an important psychological boost.
Bicep Anatomy 1.01
Elbow flexion work isn’t all biceps; there are three main muscles we need to know about before we start training. Here’s a quick overview of each of them in turn:
This is the daddy I guess; the biceps brachii is the muscle the gives the upper arm that ‘peak’ when flexed. Whilst it may have a reputation as a simple elbow flexor, the bicep is actually a tri-articulate muscle – meaning it works over three joints. In addition to flexing the elbow it also acts to flex the shoulder, albeit rather weakly, and to supinate the forearm (think turning the palms up). It has two different heads, a long head (originating from the supraglenoid tubercle) and a short head (originating from the coracoid process of the scapula).
- Its best line of pull is in supination.
- The biceps brachii is at a mechanical disadvantage in pronation (palms down).
- Because it originates from the glenoid, as the shoulder goes into extension the long head of the biceps is put under stretch. Any exercise performed in, or moving towards, shoulder extension emphasises the long head.
- Now think the opposite. Shoulder flexion takes the emphasis off the long head and therefore more towards the short head.
- As speed of movement increases, so too does relative biceps brachii recruitment.
It may be in the forearm but it’s most definitely an elbow flexor. The muscle originates on the lateral ridge of the humerus and inserts on the distal aspect of the radius. Because of this insertion, in addition to flexing the elbow, the brachioradialis can both pronate and supinate the forearm.
- Its best line of pull is in neutral (palms facing each other).
- Because the biceps brachii is disadvantaged in pronation, the relative activation of the brachioradialis is increased.
- From a pronated position it will tend to supinate as it flexes; the opposite is true starting from a supinated position.
The brachialis lies just underneath the biceps brachii and serves only to flex the elbow. It originates on the humerus and inserts on the ulna – because it doesn’t insert on the radius, it can’t pronate or supinate the forearm.
- Its best line of pull is in pronation.
- It becomes more active during slower movement speeds and isometric pauses.
As the name may suggest, the primary function of this little muscle is to pronate the forearm. It is, however, also a weak elbow flexor. To target this we’re looking to pronate, so we’ll throw it in with brachialis for the meantime.
Imbalances aren’t good. Not only will they increase the risk of injury, but they will halt any improvements in strength or power. If your arm training hasn’t progressed since the days when reality TV was a ‘new and exciting concept’ then I’ll wager that you’ve got some issues here. There are three types of relationship we need to consider:
Between the respective Elbow Flexors
Although to varying degrees, all of the elbow flexors are involved in each curl variation; you’re only ever as strong as your weakest link. Renowned strength coach Charles Poliquin has outlined an optimal ratio of elbow flexor strength. Reverse curl (pronated grip) strength should be around 80% of your standard supinated strength whilst neutral curl strength should be 15% greater than supinated. How do your reverse curls compare?
Between the Flexors and Extensors
Muscles like to work in pairs; when one is working, the other is braking. Strong triceps (and anconei) reduce inhibition of the elbow flexors and allow them to work harder and more efficiently. Think of in terms of driving a car, you can’t really exploit the true potential of the engine (flexors) if the brakes (extensors) aren’t able to deal with it. Not as much of an issue as the other two in my experience, but an important consideration nevertheless.
Between the Upper Arm and Forearm
To return to the car analogy, the forearms act a bit like the gear box. A second rate gear box won’t allow you to transmit the force from the engine (flexors) to the wheels (joint). If the body thinks that muscles of the forearm – and we’re not just talking about the ones that flex the elbow – simply aren’t strong enough, then it will limit activation of elbow flexors in effort to protect them. In the long term, if such imbalances are not addressed, we’re also risking problems occurring at the elbow.
Hopefully this little summary has given you a bit of a background to arm work. If you stay tuned for the next part we’ll put the theory into practice and go through some of my favourite exercises.