“. . . according to the Yoga Sutra (3.1), the term [Bandha] refers to the ‘binding’ of consciousness to a particular object or locus (desha), which is the very essence of concentration.” Georg Feuerstein
William Blake said you can see the world in a grain of sand. Similarly, fundamental principles you master in one asana are portable to others. With this in mind, let’s look at the key elements for activating your foot arch in the front leg foot in Trikonasana (Triangle Pose). Here’s the cue…
First, press the outer edge of your foot into the mat. This engages the tibialis anterior and posterior muscles of the lower leg (figure 1).
Figure 1
Maintain that action as you press the ball of your foot into the mat. This engages the peroneus longus and brevis muscles on the outside of your lower leg (figure 2).
Figure 2
Co-activating the muscles that invert (supinate) and evert (pronate) your foot creates an opposing force between these two antagonistic actions that stabilizes your ankle.
These same muscles work together (as synergists) to lift your foot arch (figures 3 and 4).
I hope you enjoyed this blog post. Page through the Key Muscles and Key Poses of Yoga and the Yoga Mat Companion Series to learn more about anatomy and biomechanics for yoga. See you next week when I will post another tip on anatomy and biomechanics for yoga.
In this post, we continue our journey through Trikonasana (Triangle Pose) with a cue that connects the forward leg psoas with the back leg glutes, thus stabilizing your pelvis.
First, take a quick look at the cue from my previous post on co-contracting the psoas and quads of your forward leg. Engage the forward leg psoas and quads and then add contraction of the rear leg gluteus maximus (and quadriceps) as shown here in figure 1.
Figure 1: Co-contracting the psoas and glutes in Trikonasana.
The psoas creates a force that tilts the forward leg side of the pelvis (hemipelvis) forward (anteversion) while the gluteus maximus creates a retroversion force on the back leg side hemipelvis. You will feel how combining these opposing forces creates stability. Figures 2 and 3 illustrate this concept.
Figure 2: The opposing forces of the glutes and psoas and the posterior SI ligaments stabilizing the pelvis.
Figure 3: Opposing forces of the psoas and glutes and the anterior SI ligaments stabilizing the pelvis.
Sometimes doing just one pose can set you up for the whole day. Let’s look at Trikonasana or Triangle Pose and a powerful cue for stabilizing your pelvis and lumbar. Understanding tips like this one also sharpens your knowledge of anatomical and biomechanical principles.
The principle at work here is that of muscle co-contraction. This cue co-contracts or activates two separate muscles, namely, the psoas and quadriceps of the forward leg. As a consequence, you will feel a deep stability in your hip joint and a connection from your leg to your lumbar spine.
Here's the cue:
Extend your forward leg knee by contracting the quadriceps. At the same time, press down with your torso through the arm into the hand, and onto your shin. This activates your psoas (and iliacus), tilting the pelvis over the forward leg and, by lumbopelvic rhythm, drawing the lumbar out of hyperflexion. Feel how this connection stabilizes your pelvis and lumbar and awakens the forward leg in the pose.
Figure 1:Co-activating the psoas and quads in Trikonasana
I hope you enjoy this cue. Think about what's happening biomechanically while you work with this. Thanks as well to everyone for your support of the folks in Panama City who were affected by Hurricane Michael. Check back next week to see how to integrate the back leg into this cue for Trikonasana.
Foundational knowledge gives you power that you can translate into applications for your practice and teaching.
In this blog post, I explore some of the essential biomechanics of the shoulder joint, especially the “force couple” between your deltoid muscle and the rotator cuff. Understanding this relationship helps build your fund of knowledge regarding this complex articulation, which can help you later on in developing cues for your practice as well as well as for therapeutics in yoga.
The “force couple” is a biomechanical concept whereby groups of muscles work together around a joint to produce coordinated movement. The force couple between the rotator cuff and the deltoid muscle works in concert with other muscles around the scapula to produce movements such as raising the arm overhead.
The shoulder joint proper is a ball and socket joint comprised of the humeral head which articulates with the shallow glenoid fossa (socket) of the scapula. The bone shapes of the shoulder joint allow for a high degree of motion. Contrast this with the hip joint, where the socket is much deeper and constraining on motion. In addition to the bony stabilizers, there are also soft tissue stabilizers such as ligaments and the labrum and muscular dynamic stabilizers. Figure 1 illustrates the bones of the shoulder. Click here for more on this in relation to your Down Dog.
In the force couple between the deltoid muscle and the rotator cuff, the rotator cuff stabilizes the humeral head against the glenoid fossa. The deltoid muscle then levers the humeral head off the glenoid fossa to raise the arm. At the same time, the scapula and clavicle rotate to aid in producing movement, a process known as scapulohumeral rhythm (click here for more on this subject).
Figure 2 - The Subscapularis / Infraspinatus force couple.
Figure 3 illustrates the force couple between the
rotator cuff and the deltoid muscle. Click here to learn about the supraspinatus muscle of the rotator cuff. As the deltoid contracts to raise the arm, the rotator cuff contracts to stabilize the humeral head in the socket. All of this happens automatically--the brain is hard wired for this force couple.
Figure 3 - The Deltoid / Supraspinatus force couple.
Injury to the rotator cuff, such as a tear or inflammation can lead to less efficient stabilization of the humeral head in the socket. As a consequence, when the deltoid contracts, instead of levering the humeral head off the glenoid, the force of the deltoid contraction causes the head of the humerus to shift upwards into the subacromial space. This can lead to impingement of the rotator cuff on the undersurface of the acromion, thus exacerbating the condition. To compensate, the body uses abnormal movement of the scapula in an attempt to stablize the humeral head in the socket. This abnormal movement of the scapula on the chest wall is known as “scapulothoracic dyskinesia”. I examine for this by comparing the movement of the normal and injured side from the back while having the patient raise the arms overhead.
Figure 4 - Raising the arms over the head in Warrior I and Tadasana.
I hope this post helps you build your fund of knowledge regarding shoulder biomechanics. Stay tuned for my next post where I discuss some of the yoga poses that can be used to stretch and strengthen the rotator cuff. Learn more about anatomy, biomechanics and physiology for your yoga in “The Key Muscles of Yoga”, “The Key Poses of Yoga” and the Yoga Mat Companion series. Click on any
of these books to page through.
