Can Reverse Abdominal Breathing Change the Way the Legs Work During Tai Chi/Qigong?
Breathing is often treated as something that happens in the background while we move. We walk, stretch, lift, or practise Tai Chi while the lungs quietly continue their work. Yet breathing is also a physical action. The diaphragm rises and falls, pressure shifts inside the abdomen, and muscles around the trunk respond. The body then makes constant small adjustments to remain balanced.
Change the way someone breathes, and you may also change how the rest of the body organizes movement.
A 2025 study published in Frontiers in Bioengineering and Biotechnology explored this idea by comparing natural breathing with reverse abdominal breathing during a familiar Tai Chi movement. The researchers wanted to know whether changing the breath would affect muscle force, joint stability, or the coordinated patterns through which the leg muscles work together.
Their findings suggest that breathing technique may influence much more than the abdomen. In experienced Tai Chi practitioners, reverse abdominal breathing increased the involvement of several important lower-limb muscles and changed how the body coordinated balance and weight transfer. The results are intriguing, although they need to be interpreted with some care.
What Is Reverse Abdominal Breathing?
During ordinary abdominal breathing, the abdomen generally expands as we inhale. The diaphragm descends, the abdominal contents shift slightly, and the abdominal wall moves outward. As we exhale, the abdomen settles inward again.
Reverse abdominal breathing changes this pattern. The practitioner gently draws the abdomen inward during inhalation, then allows the abdominal wall to release and expand during exhalation. In Tai Chi and related internal practices, this method is often synchronized with specific phases of movement rather than practised as an isolated breathing exercise.
That synchronization was central to the study. Participants inhaled while rotating the torso and lifting the leg, actively drawing the abdomen inward. They exhaled as the foot landed and the body weight shifted forward, allowing the abdomen to release.
The researchers described this relationship as “breathing-posture synchronization.” The breath was not simply added to the movement. It became part of the movement’s timing and organization.
This matters because breathing changes pressure within the trunk and involves the diaphragm, abdominal wall, pelvic floor, spinal muscles, and other structures that help stabilize the torso. Since the pelvis forms the foundation for the legs, changes in trunk control may influence what happens at the hips, knees, and ankles.
How the Study Was Conducted
The study included 15 experienced Tai Chi practitioners, nine men and six women. Their average age was approximately 38, and each had more than five years of Tai Chi experience. None had joint, muscular, or other health problems that would prevent them from completing the movement safely.
The researchers examined part of the movement commonly known as Wild Horse Parts Its Mane. This was a useful choice because the movement combines several physical demands. The practitioner must briefly support the body on one leg, rotate the torso, step forward, transfer weight, and control the landing.
The researchers focused on the phase in which the left leg supported the body while the opposite leg moved forward and the centre of mass shifted. Each participant performed the movement under two conditions. First, they used natural breathing without consciously controlling its depth or timing. They then repeated the same movement using reverse abdominal breathing synchronized with the action.
Before the reverse breathing trials, the participants completed ten minutes of practice. A metronome helped establish a two-second inhalation during torso rotation and leg lifting, followed by a three-second exhalation during landing and forward weight transfer.
Several technologies were used to record what was happening. A high-speed motion-capture system tracked the participants’ movements, while a force platform measured the forces travelling between the foot and the ground. Surface electromyography, usually called EMG, recorded electrical activity from nine muscles in the supporting leg.
These included the gluteus maximus in the buttock, the quadriceps at the front of the thigh, the hamstrings at the back of the thigh, the gastrocnemius muscles in the calf, and the tibialis anterior along the front of the lower leg.
The research team also used a computer modelling program called OpenSim to estimate muscle force, joint movement, and joint stiffness. They compared the model’s estimates with the EMG recordings and found a reasonably strong relationship between them, lending some support to the reliability of the simulation.
The final part of the analysis looked at muscle synergy.
How the Nervous System Organizes Movement
The brain does not necessarily control every muscle as a completely separate unit. Instead, the nervous system appears to organize muscles into functional groups that can be recruited together. Researchers call these groups muscle synergies.
Imagine stepping forward while trying to remain balanced. The brain must coordinate muscles around the hip, thigh, knee, ankle, and foot. If every muscle had to be controlled independently, even a simple step would become enormously complicated. Muscle synergies may simplify this task by allowing the nervous system to activate groups of muscles in coordinated patterns.
The researchers used a mathematical analysis to identify these patterns in the participants’ EMG recordings. They found three main synergy groups under both breathing conditions.
The number of groups did not change. What changed was the contribution and timing of particular muscles within them. Reverse abdominal breathing did not create an entirely new way of moving. It appeared to adjust the emphasis within movement strategies the participants were already using.
Greater Force in Several Important Muscles
The clearest result was an increase in the estimated peak force of several lower-limb muscles. Compared with natural breathing, reverse abdominal breathing produced greater force in the gluteus maximus, rectus femoris, biceps femoris, semitendinosus, and tibialis anterior.
All of these muscles contribute to stepping and weight transfer. The gluteus maximus helps control the hip as the body moves from one leg to the other. The rectus femoris contributes to both hip and knee control. The biceps femoris and semitendinosus are hamstring muscles that help stabilize the hip and knee. The tibialis anterior helps control the ankle and the placement of the foot.
Together, these muscles support the body as the centre of mass moves forward.
This does not necessarily mean that the participants were simply working harder. Reverse breathing may have changed how effort was distributed throughout the movement. Greater recruitment of the hips and thighs could help the body manage weight transfer more effectively, rather than relying mainly on small corrections around the ankle.
The authors suggested that drawing the abdomen inward during inhalation may have increased trunk engagement and pressure within the abdomen. This could provide a more stable central base from which the leg muscles operate.
That explanation is reasonable, but it was not directly tested. The study did not measure abdominal pressure, pelvic-floor activity, or diaphragm movement. These remain possible mechanisms rather than confirmed findings.
A Firmer Knee and Ankle
Reverse abdominal breathing also increased stiffness at the knee and ankle. In biomechanics, stiffness does not necessarily mean that someone is tense, rigid, or inflexible. It refers to how strongly a joint resists movement when force is applied.
A moderate amount of stiffness can be useful because it helps stabilize the body during stepping, landing, and unexpected changes in balance. Muscles on opposite sides of a joint often contract together to create this stability.
At the knee, coordinated activity between the quadriceps and hamstrings can help control the joint as the body moves forward. At the ankle, muscles at the front and back of the lower leg work together to manage sway and foot placement.
The study found that reverse abdominal breathing changed the activation relationship between the tibialis anterior and lateral gastrocnemius. The balance shifted toward greater involvement of the tibialis anterior, which may have contributed to the increase in ankle stiffness.
The participants did not become excessively rigid. The authors noted that the changes were small to moderate and well below the levels normally associated with high-intensity exercise. A reasonable interpretation is that reverse abdominal breathing helped create a firmer but still adaptable lower-limb structure during weight transfer.
Breathing and Balance Strategy
Human beings use several overlapping strategies to remain upright. For small balance adjustments, we often rely on an ankle strategy. The body moves somewhat like an inverted pendulum, with muscles around the lower leg and ankle making subtle corrections.
When movement becomes larger or more demanding, the hips become more involved. This is known as a hip strategy. The knees also contribute during stepping, lowering, and forward weight transfer.
The muscle synergy analysis suggested that reverse abdominal breathing changed the contribution of muscles associated with all three regions. One synergy emphasized the hamstrings and calf muscles, reflecting a combined ankle and hip strategy. Another emphasized the quadriceps and tibialis anterior, resembling a knee-focused strategy. A third was dominated by the gluteus maximus and rectus femoris, suggesting greater hip involvement.
During reverse abdominal breathing, several of these muscles contributed more strongly. The synergy dominated by the gluteus maximus and rectus femoris also appeared to activate earlier.
That timing may matter. Postural control is not only about producing enough force. The force must arrive at the right moment. Earlier recruitment of the hip and thigh muscles may help prepare the body for the approaching weight shift and foot contact.
Breathing may therefore act partly as a timing signal. A deliberate inhalation during lifting and rotation, followed by exhalation during landing and weight transfer, creates a predictable rhythm. The nervous system may use that rhythm to organize muscular activity more effectively.
How Could the Breath Influence the Legs?
The study offers several possible explanations. Reverse abdominal breathing requires deliberate muscular control, and the abdominal wall, diaphragm, and possibly the pelvic floor must coordinate with the rhythm of the movement. This may improve stability around the trunk and pelvis, giving the legs a stronger base.
Voluntary breathing also involves parts of the brain that participate in movement. Purposeful control of inhalation and exhalation may therefore influence motor pathways connected with the limbs.
There is also the question of anticipation. When the breath is consistently linked to a particular phase of movement, it may help prepare the body for what comes next. Inhaling during leg lifting and torso rotation is followed by exhaling during landing and weight transfer. With repetition, this pattern may help organize the sequence of muscular recruitment.
The study cannot tell us which of these mechanisms is most important. It does, however, support the broader idea that breathing, posture, and limb control are closely connected.
What This May Mean for Tai Chi Practice
For experienced practitioners, the research offers a possible biomechanical explanation for something often felt during practice: changing the breath can change the movement.
Reverse abdominal breathing may encourage greater participation of the hips and thighs. It may slightly increase stability at the knee and ankle while altering the timing of muscular coordination during stepping and weight transfer. This could be relevant when Tai Chi is used to develop balance, controlled movement, body awareness, and coordinated stepping.
The findings may also have future relevance for rehabilitation, particularly in programs concerned with posture and balance. At this stage, however, reverse abdominal breathing should not be presented as a proven treatment for weakness or instability. The participants were healthy, experienced practitioners. This was not a clinical trial involving people with balance disorders.
Future research could examine beginners, older adults, and rehabilitation patients. Researchers could also measure the diaphragm, abdominal pressure, pelvic floor, and trunk muscles directly. Longer studies would help determine whether the immediate changes observed in the laboratory eventually produce meaningful improvements in daily movement.
For now, the most useful conclusion is a modest one. Breathing is not simply a background process during Tai Chi. When intentionally coordinated with movement, it may become part of the body’s strategy for producing force, preparing the joints, and maintaining balance.
The breath does not merely accompany the movement. It may help organize it.
Reference
Yin, Y., Zhang, Y., Wang, M., Zhu, Y., Bi, G., & Zhang, S. (2025). The impact of reverse abdominal breathing on lower limb muscle strength and muscle synergy characteristics in Tai Chi Chuan. Frontiers in Bioengineering and Biotechnology, 13, 1579139
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