Speaker #0Hi, and welcome to BioPilates Deep Dive. Today I'm offering you a very practical, very precise episode about an exercise that looks simple at first glance but becomes a true biomechanical gem the moment you truly respect it. Back rowing, biceps curls on the reformer. You might think it's just bending the elbows. In reality, it's an exercise that reveals everything. It reveals your scapular stability, your ability to keep the humorous still in space, your postural organization, the quality of your pronation supination, and above all, your control on the return. I love it because it doesn't allow cheating. The reformer becomes a mirror. If your strategy is clean, the carriage glides as if it were obvious. If you compensate, the carriage tells you immediately. Before we talk about the movement itself, I need to lay down an essential foundation. The elbow is not an isolated joint, it's a complex. When you do a biceps curl, you involve several joints that work together within a shared capsule. You have the humeralner joint, the primary hinge for flexion and extension. You have the humeral radial joint between the capitulum of the humerus and the head of the radius, which is crucial for stability and force transmission. And you have the proximal radial joint, a pivot that allows pronation and supination. So even before we talk about muscles, we have to understand that this simple gesture is supported by an intelligent architecture. That architecture is first and foremost bony. The distal humerus carries the trochlea, a pulley-shaped surface that fits into the trochlear notch of the ulna. This is what precision. It also carries the capitulum, more lateral, which receives the radial head. The ulna forms a kind of clamp around the trochlea, with the olecranon acting as a bony stop and extension and the coronoid process playing an important role in flexion. The radius is the bone that pivots, its head rotates inside a stabilized ring, and its radial tuberosity is a key landmark because it is the insertion site of the distal tendon of the biceps brachii. And that detail changes everything. Depending on whether your forearm is in pronation or supination, the radial tuberosity is oriented differently and the biceps mechanical advantage changes. That's why hand position is never just a detail. Then we have the ligaments, the silent guardians of movement. They should never become the main actors, but they ensure the joint remains congruent and stable. The medial collateral ligament is a major stabilizer against valgus forces, forces that would open the elbow on the medial side. The lateral collateral complex protects against virus forces and helps prevent posterolateral instability. And the annular ligament of the radius is absolutely central. It holds the radial head against the ulna while allowing rotation. Without it, pronation supination would be unstable. So in an exercise like the biceps curl on the reformer, our priority is not to test these ligaments but to respect them. We don't want parasitic twisting, lateral deviation or harsh traction. We want muscular force to travel through cleanly And that brings us to the muscles, because that's often where attention gets stuck. The two protagonists today are the biceps brachii and the brachioradialis. The biceps brachii has two heads. The long head originates from the supraglenoid tubercle of the scapula and crosses the shoulder. The short head originates from the coracoid process of the scapula. They join and end in a distal tendon. that inserts onto the radial tuberosity. The biceps also has a fascial expansion, the bicipital aponeurosis, which fans out into the forearm. It is innervated by the musculocutaneous nerve, mainly through C5 and C6, sometimes with C7 involvement. Its key actions are elbow flexion and forearm supination. Its supination is especially effective when the elbow is flexed So this muscle is not only a powerful elbow flexor, it's also a major supinator. The brachioradialis is a forearm muscle on the lateral side. It originates from the lateral supracondylar ridge of the humerus and inserts on the distal radius near the radial styloid process. It is innervated by the radial nerve, mainly via C5 and C6. Its primary action is elbow flexion, but it is particularly effective in a neutral forearm position, the handshake position with the thumb pointing up. And it has an interesting capacity to bring the forearm back toward neutral when coming from extreme pronation or supination. What I want you to remember is that pronation and supination don't just change the shape of the movement. They change the mechanics of the radius, the biceps lever arm, and therefore neuromuscular recruitment. In supination, palms up, the biceps is mechanically favored. In pronation, palms down, the biceps loses part of its advantage, and the brachioradialis becomes more prominent. In a neutral grip, palms facing in, The brachioradialis is often highly efficient and the sensation is often more comfortable for many bodies. Now, let's return to the exercise itself. I'll give you the classic version, the way I teach it. Set the foot bar to position 1. Choose one or two springs depending on the level, stability, and shoulder comfort. The headrest is flat. Sit tall. Pelvis and spine neutral. Legs are straight, adducted. Thank you. Keep the scapulae stable and the humerae still in space, and flex the elbows to bring the hands toward the ears and push the carriage. Then inhale. Keep the scapulae stable and extend the elbows to control the carriage back. Do 5 to 10 repetitions, slowly, with a steady rhythm, without rushing. And now the most important point in the entire exercise, the one that changes everything. Keep the upper arm at a constant height and do not overuse the upper trapezius. This is where most compensations appear. When it gets difficult, many people lift the shoulders, shorten the neck, and turn a curl into a shoulder pull. But if the shoulder moves, you change the length of the biceps because the biceps crosses the shoulder. You change the line of pull and you create parasitic stress at the elbow. So the first discipline is, do not negotiate with the shoulder. Mobility is at the elbow. Stability is at the scapulae. I also want to emphasize the return of the carriage. In my mind, the return is a matter of movement ethics. Many people know how to produce effort. Few know how to give it back. Yet the eccentric phase is the zone of control and protection. If you let the carriage pull you, you create a harsh traction. You overload the tissues. you lose the quality of the gesture. So we slow down the return, we keep the organization, we breathe and we remain in charge of the movement. The variations are very interesting. You can do the exercise with palms down. There you recruit more brachioradialis and explore a different mechanics. You can do it palms facing in in a neutral grip which is very functional and often very comfortable. You can also add a dynamic rotation: start palms up, move into palms down during the flexion, then return during the extension or the reverse: start palms down, move into palms up during the flexion and reverse again during the extension. These variations are beautiful because they train pronation-supination coordination while demanding impeccable scapular stability and they immediately reveal whether you break the wrist, Grip with the hand or lose your axis. If I had to summarize the essence, I would say this: This is not an exercise to work your arms. It's an exercise to learn how strength and precision can coexist. It's an exercise to understand that the elbow is a complex, that forearm position changes biomechanics, that ligaments are there to protect, not to compensate, and that scapular stability is the condition for true freedom at the elbow. And above all, it teaches you something rare, strength that remains civilized, power that doesn't turn into brutality, control that protects. Thank you for listening to Biopolites Deep Dive. See you in the next episode of Biopolites Deep Dive.
