May 2021

Is Standing on 2 Feet Such a Complex Task?

Figure 1. People waiting for the bus.

By Dalia Zwick, PT, PhD – Images created by the author

The answer is Yes and here is how to tune it. Standing upright: step-by-step instructions.

Whenever I have the chance, I enjoy observing people’s standing posture while waiting for a bus at the NYC Port Authority Bus Terminal in New York City.  Most people are preoccupied with their phones and ignore how they stand. Some stand passively, bearing weight mostly on a single leg in an asymmetrical posture. Some bend one knee and turn in their ankle. It got me wondering: is this way of standing helping them (subconsciously) in energy efficiency or is it doing harm to body posture? Do people need directions for how to stand?

The answer is YES, maybe they do need directions for how to stand.

In yoga, standing posture is a key element and practicing it is a foundation to one’s successful practice of all other yoga poses.

Teaching how to achieve standing posture is a quill in every good yoga teacher’s quiver. And after many years of being a practicing physical therapist and practicing yoga, it’s clear that yoga’s step-by-step directions can help most patients (and for that matter other people as well) stand upright in a manner that will not cause pain or damage now or down the road, and may even provide additional benefits.

Maintaining proper posture during standing is linked to reducing improper stress and strain on body structures. Poor habitual posture that is not attended to is associated with clinical symptoms in chronic pain patients; improvements in postural awareness through body-mind programming are longitudinally associated with reduced pain in patients with spinal/shoulder pain.1

Research shows that abnormal habitual postural patterns are associated with musculoskeletal pain, and posture improvement leads to pain reduction.

Figure 2. Yoga standing posture consists of kinetic alignment from toe upwards to head, feet straight forward, hip width apart.

Scientific Perspective on Posture

In response to evolutionary need, humans stand upright with the chain of balance (kinetic chain) starting at the feet, working upwards through the ankles, knees, hip joints, and pelvis, then through each spinal segment and finally ending at the cranium, thus allowing us to have a horizontal eye view of the world and to achieve balance using minimal energy (muscle activity).2

Some professionals see no value in attending to good standing posture as they report that there is lack of evidence correlating pain with impairment in posture.3 However, most research supports a direct correlation.4 This research suggests that standing for long periods of time creates fatigue. The body, when experiencing fatigue from long duration standing, will start shifting weight to one side or the other, creating asymmetry that affects the spine and thereby the whole body. Some people tend to react by locking (hyperextending) their knees and or “swaying their back,” which increases their lordotic curve.5 In long duration standing, foot posture changes as the foot and ankle complex will pronate more on the engaged weight-bearing foot and supinate on the ipsilateral foot. Poor foot posture is known to be a risk factor for hip and knee injuries.6

When looking at standing posture we need to distinguish between 2 states:

  • Dynamic posture, which is how the body adapts to changing circumstances, or
  • Static posture, which is how the body is held actively standing in one place. This is usually achieved by coordination and interaction of various muscle groups that work statically to counteract gravity and other forces.

In the context of this article, we relate to standing as a static posture; however, the step-by-step instructions can help when attending to a more dynamic posture.

Good Standing Posture How-To

Step 1. Stand with feet closely touching at the big toes or hip-width apart but almost parallel to each other (sagittal plane) with heels slightly turned outward (hips internally rotated). Weight is distributed evenly between the heels and the toes on both feet (Figure 3).

Proper standing posture starts with foot placement: Stand with feet slightly touching at big toes, with heels slightly turned out.

Figure 3. An example of good standing posture: note heels slightly turned out.

While a seemingly simple instruction, the placement and direction of the foot has a significant impact on the proper alignment of the proximal joints such as the knee and hip. In biomechanics, inverse dynamics is used to explain that the distal component, here the foot, influences the alignment of knee and hip position. The position, direction, and movement of the foot in standing is part of a kinematic chain where movement at the distal joint produces or affects movement at the proximal joint in the kinetic link.7 In other words, when you move one end of the kinetic chain, you influence all the proximal components of said chain.

Evolutionary Error?

The hip joint is a ball and socket joint that consists of 2 bones: the femur and the acetabulum, which is part of the pelvis (Figure 4). The ball-and-socket joint, also called a spherical joint, is a joint in which the rounded surface of a bone (the ball-head of the femur) moves within a depression or socket (the acetabulum of the hip) on another bone, allowing greater freedom of movement than any other type of joint.

However, when a person stands erect in a relaxed posture, the hips are in a straight position that corresponds to the erect standing posture with feet pointing out, thus the femur’s head is not entirely covered by the acetabulum. The head of the femur is exposed superiorly and anteriorly (in the socket, Figure 4C), creating a “black crescent.”8  This means that the head of the femur and acetabulum (socket) have some areas that are uncovered or incongruous; this incomplete contact positioning contributes to load distribution changes which may cause bone and joint changes.9 Over time, these repeated minor changes can lead to the development of osteoarthritis in some individuals.

How to correct the incongruity? Align feet and legs in standing so that toes are either slightly touching or close to each other, with heels out or feet paralleled as noted above.

In evolutionary terms, this correct physiological position of the hip corresponds to the quadruped position on all fours. Kapandji observed that during evolution, the transition from the quadruped to the biped state led to the loss of coincidence of the articular surface of the hip joint.8 Figure 5 depicts the flexion, abduction, and external rotation at the hip joint akin to a quadruped stance; here, the hip joint has the best coincidence of the articular surface.

To get the same amount of joint coincidence in a bipedal standing positioning stance, the hip is extended, adducted and internally rotated, so foot/toes need to be slightly inward with heels apart as displayed in Figure 6.

Figure 4. A) The hip joint consists of the femur, left, and the acetabulum of the pelvis, right. B) When feet point outward while standing, the femur head does not sit properly in the acetabulum, creating a “black crescent.” C) The ball-head of the femur moves within the socket created by acetabulum.

My Clinical Perspective

My interest in step-by-step instruction for proper standing posture came from my desire to add expertise to my physical therapy background which uses a manual skill biomechanics rationale. Therapists assess standing by viewing posture as static and dynamic body alignment, including symmetry and deviation from midline. As a therapist, I know how to perform evaluation and manual correction of standing posture; however, I felt I lacked the knowledge in how to give step-by-step verbal instruction of a good standing posture. That’s where my Iyengar Yoga practice and training comes in.

“I will teach you how to stand on your own 2 feet,” B.K.S. Iyengar, the Indian yoga guru, told Mary Palmer when she asked to train with him decades ago. Ms. Palmer, who would become mother to Mary Dunn who would become a well-known Iyengar Yoga teacher, ended up spending years studying with Guru Iyengar during her stays in India and in other places he taught. In turn, Ms. Dunn opened the first Iyengar Yoga Institute in America in 1976; today, she is credited as the person who introduced Iyengar Yoga to the United States, where at present, it has millions of dedicated practitioners. I was lucky enough to have her as a teacher and a friend.

Iyengar Yoga is a style or method of Hatha Yoga that follows a specific sequence of poses. These pose sequences are to be practiced with great attention given to the precision of postural/physiological alignment. Iyengar’s attention to alignment is evident when he said, “People do not pay attention to the correct method of standing. …It is therefore essential to master the art of standing correctly.”10

Figure 5. This position depicts the flexion, abduction, and external rotation at the human hip joint that is akin to a quadruped hip joint stance; here, the hip joint has the best coincidence of the articular surfaces between the femur and the acetabulum.

Standing correctly is essential in Iyengar Yoga practice and teaching how to do so is an artform in itself. I respect how yoga teachers can instruct a large group of people in correct standing posture with words and demonstration only. I am still in an awe at how everyone in a group of hundreds at times can correctly follow the verbal instructions.

The yoga pose of Tadasana or Mountain pose, the basis for all other poses, is considered the easiest and yet most complicated yoga pose. Tadasana is a static standing posture where a practitioner is following instructions to correctly align bones and joints and isometrically activate supportive muscles. These key muscles allow bones at different regions of the body to stay in proper alignment. Physical therapists often resort to the use of their hands to instruct, direct, guide, or support regions of the body of a person they work with. This manual hands-on approach allows therapists to accurately guide the person according to their unique needs. This leaves room to an interpretation by the therapist who might assume what their patient’s needs are, and to dependency in the patient for a therapist’s sensory feedback. Outcome assessment is difficult as different therapists rarely approach a patient in the same way.

Being an Iyengar Yoga practitioner, I find it helpful to follow the same set of instructions when taking yoga classes from different teachers even at different locations. These instructions can be helpful in different scenarios such as when a patient needs manual assistance, or is placing a young child in a stander, or a patient with foot, knee, and hip pain is visiting a podiatrist.  Medical providers or caregivers can follow these step-by-step instructions even as a home exercise program.

Iyengar Yoga Standing Instruction

In yoga, standing is considered the basis of all poses. It is called Smasthiti, which means a balance pose where both sides of the body are symmetrical, balanced in stillness. In Hindu, attentive standing or standing with awareness is called Samasthiti. The posture assumed in Tadasana or Mountain pose invokes Samasthiti

Figure 6. To achieve hip joint coincidence comparable to a quadruped, when standing bipedal, the hip is extended, adducted, and internally rotated so foot/toes point slightly inward and heels are apart.

To stand with awareness:

  1. Stand with feet together. Feet should stay either parallel to each other or joined at the big toes with heels turned outward. Thighs (femur) should be actively engaging muscles in adduction, extension, and internal rotation. This is the most important point; one can benefit from following this point alone.
  2. Do not clench the toes. Instead, extend them from the mounds to the tips and spread them wide. Stretch the sole of the foot from the tips and spread the middle to the sides, as if ironing out any creases.
  3. “Grip” the kneecaps and lift them upwards, engaging the knee extensors.
  4. Contract the buttock muscles and lift the quadriceps (frontal thigh muscles) up toward the pelvis.
  5. Roll the frontal thighs from outside in and the back of the thighs from inside out.
  6. Lift the lower abdomen vertically up: do not allow it to protrude. (This might also be thought of as engaging the core.)

Dalia Zwick, PT, PhD, is a Senior Rehab Supervisor in NYC Health Care clinics that support healthcare needs of people with intellectual and developmental disabilities.

REFERENCES
  1. Cramer H, Mehling WE, Saha FJ, Dobos G, Lauche R. (2018). Postural awareness and its relation to pain: validation of an innovative instrument measuring awareness of body posture in patients with chronic pain. BMC Musculoskelet Disord. 2018;19(1):109.
  2. Hasegawa K, Okamoto M, Hatsushikano S, et al. Standing sagittal alignment of the whole axial skeleton with reference to the gravity line in humans. J Anat. 2017 May;230(5):619-630. 
  3. Slater D, Korakais V, O’Sullivan P, Nolan, D, O’Sullivan K. “Sit up straight”: time to re-evaluate. J Orthop Sports Phys Ther. 22019;49(8):562-62.
  4. Hunter DJ, Rivett DA, McKeirnan S, Smith L, Snodgrass SJ. Relationship between shoulder impingement syndrome and thoracic posture. Phys Ther. 2020;100(4):677–686.
  5. Harris L. Sit Stand Stations. OH&S. Feb. 1, 2012.  Available at https://ohsonline.com/articles/2012/02/01/sit-stand-stations.aspx. Accessed May 10, 2021.
  6. Buldt AK, Allan JJ, Landorf KB, Menz HB. The relationship between foot posture and plantar pressure during walking in adults: a systematic review. Gait Posture. 2018;62:56-67.
  7. Ellenbecker TS, Davies GJ. Closed kinetic chain exercise: a comprehensive guide to multiple joint exercises. New York, NY: Human Kinetics; 2001.
  8. Kapandji IA. The Physiology of the Joints. Vol. 2: the lower limb. Edinburgh, New York; Churchill Livinstone.Elsevier; 2011.
  9. Li AE, Jawetz ST, Greditzer HG IV, et al. MRI for the preoperative evaluation of femoroacetabular impingement. Insights Imaging. 2016;7(2):187-98.
  10. Iyengar BKS. Light on Yoga. Revised ed. New York, New York; Harper Collins Publishers; 2001.

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