How Much Muscle Activity Are We Using In Standing Postures?


December 15, 2020     ankle | muscle | Standing Postures | Yoga Postures | Yoga Research

Yoga postures vary in their demand on leg muscles

Research Study At A Glance

The Research Question Asked

How much are our leg muscles working in standing yoga postures?

Type of Study

Clinical research study

Study Participants (Sample)

Sample size: 10 total participants

  • Female
  • Mean age 23.9
  • At least three months of yoga experience

Methods

Researchers recorded electromyographic (EMG) data for four leg muscles in three standing yoga postures: half moon, tree pose, and warrior three.

Results

  • In warrior three pose, tibialis anterior (a leg muscle), biceps femoris (one of the hamstrings), and gastrocnemius (a calf muscle) demonstrated more muscle activity than rectus femoris (one of the quadriceps).
  • In both half moon pose and tree pose the tibialis anterior and gastrocnemius generated more muscle activity than rectus femoris and biceps femoris.

Conclusion

Among the muscles evaluated, the muscles which stabilize and balance the ankle were more active than those that move the knee and hip. Perhaps surprisingly, single limbed balancing poses required significant activity from muscles that stabilize and balance the ankle.

Background

Yoga is an increasingly popular form of movement with many physical, mental, and emotional benefits. Practitioners and teachers often consider standing postures, such as tree pose and mountain pose, to be fundamental postures in the practice of yoga. These fundamental standing postures are common to many styles of yoga asana practice. Yet, little has actually been done to measure what muscles are working in the body when we hold these poses, or how much those muscles are working. Researchers have investigated other types of exercise to learn more about which muscles are active in the movements required and how much muscular activity is needed. A similar investigation of muscle activity in yoga postures will allow researchers to compare the kind and amount of muscle activity in yoga with the muscle activity of other kinds of exercise.

Research question

How much are our leg muscles working in standing yoga postures?

Research methods

Sample: total participants = 10

  • All female participants
  • Mean age = 23.9
  • All had at least three months of yoga experience, which was defined as doing a home practice for at least 1.5 hours/week

Researchers used electromyographic (EMG) data to assess leg muscle activity. They evaluated the muscle activity of the following four muscles:

  • Tibialis anterior (does inversion and dorsiflexion of the ankle)
  • Gastrocnemius (calf muscle which does plantar flexion of the ankle)
  • Rectus femoris (a quadriceps muscle which extends the knee and flexes the hip)
  • Biceps femoris (the lateral hamstring which flexes the knee and extends the hip)

They evaluated muscle activity in the following four postures:

  • Mountain = tadasana
  • Half moon = ardha chandrasana
  • Tree pose = vrksasana
  • Warrior three = virabhadrasana three

The research team randomized the order of the poses for each participant. But, each person still did each pose three times and then researchers recorded EMG data for at least 20 seconds with a 60 second break in between each repetition. They recorded EMG data for at least 20 seconds, three times.

Results

Warrior three: tibialis anterior, biceps femoris, and gastrocnemius had more muscle activity than rectus femoris.

Half moon pose: tibialis anterior and gastrocnemius had more muscle activity than rectus femoris and biceps femoris. Muscle activity of rectus femoris and biceps femoris were not different from one another.

Tree pose: tibialis anterior and gastrocnemius had more muscle activity than rectus femoris and biceps femoris. Muscle activity of rectus femoris and biceps femoris were not different from one another.

Generally, among the muscles evaluated, the muscles which stabilize and balance the ankle were more active than those that move the knee and hip.

Why is muscle activity relevant to yoga practitioners?

As there are many different populations that gravitate towards yoga movement. Those populations include groups such as older folks or those recovering from sports-related or other types of injuries. So, it’s useful to know how the body is working in yoga and how much. This knowledge can help instructors intelligently sequence and plan classes for different populations. This study highlights the amount of activity that muscles need in order to stabilize and move the ankle joint, particularly in single-limbed balancing poses. While we might consider the need to modify standing balance postures for older yoga participants or those recovering from injuries, we might not think to consider the health and stability of the ankle joint when we suggest those modifications. This study reminds us that the feet and ankles are our foundation in standing postures and are important to consider with respect to any change we make in the postures.

Conclusion

Yoga postures vary in the amount of muscular effort that they require. We wouldn’t necessarily be surprised that standing postures require muscular effort from the leg muscles. But, we might not consider the amount of effort required in the muscles that stabilize the ankle. Especially when doing a standing balance pose, it’s important to consider the contribution of the feet and ankles, as they are our foundation in those poses
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Reference citation

Kelly, K.K., K. Giannico, G. Lesnett, A. Romano. 2019. A comparison of EMG output of four lower extremity muscles during selected yoga postures. Journal of Bodywork and Movement Therapies. 23:329-333.

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