Somatic shaking is a body-based practice that uses intentional tremoring to release physical tension linked to stress and trauma. The idea is simple: when your body gets stuck in a stress response, guided shaking can help discharge that trapped energy the way animals naturally do after a threat passes. It draws from two main therapeutic frameworks, Somatic Experiencing and Trauma Releasing Exercises, both rooted in the observation that the body holds onto stress long after the mind has moved on.
The Theory Behind It
The concept traces back to psychologist Peter Levine, who noticed something striking about wild animals. Despite facing constant life-threatening situations, animals rarely show lasting signs of trauma. His explanation centers on the freeze response, the third survival reaction after fight and flight. When an animal (or a person) can’t fight or run, the nervous system hits a kind of emergency brake, flooding the body with energy while simultaneously locking it in place. Think of a deer going rigid in headlights.
In animals, this freeze state resolves naturally. Once the threat passes, they shake, tremble, and move until the pent-up energy discharges. Then they go back to normal. Levine’s insight was that humans often don’t complete this cycle. Social conditioning, embarrassment, or simply being told to “calm down” can interrupt the discharge process. When that happens, the massive energy prepared for survival stays trapped in the body. From the nervous system’s perspective, the threat never ended.
Somatic shaking aims to complete that interrupted cycle, sometimes years or decades after the original event.
Trauma Releasing Exercises (TRE)
David Berceli, a conflict-zone therapist, developed the most structured approach to somatic shaking after working in war zones across the Middle East and Africa. While sheltering in a bomb shelter, he held two children on his lap and felt their bodies trembling with terror. He began wondering whether that involuntary trembling might actually be the body’s attempt to process overwhelming stress rather than just a symptom of fear.
TRE uses a series of simple exercises designed to fatigue specific muscle groups, particularly the psoas, a deep hip flexor that connects the spine to the legs. The psoas is sometimes called the “muscle of the soul” in bodywork circles because of its connection to the fight-or-flight response. When these muscles tire, the body begins to tremor on its own. The shaking typically starts in the legs, moves through the pelvis and psoas, and can travel up through the spine and into the torso. People don’t force the shaking. They trigger it through specific positions and then let their body do the rest.
What It Feels Like
If you’ve never experienced neurogenic tremoring, it can feel unusual at first. Most people report involuntary vibrations or shaking that starts in the thighs or hips. The movement can be subtle, like a gentle buzzing, or more pronounced, with visible shaking of the legs or torso. It’s not painful, though it can feel strange to let your body move without conscious control.
During a session, people commonly report warmth spreading through the body, tingling sensations, and a gradual feeling of heaviness or deep relaxation as the tremoring continues. Emotional releases are also common. Some people laugh, cry, or feel sudden waves of sadness or relief without a clear reason. Afterward, the most frequently described sensation is a deep calm, similar to the feeling after a long run or a good massage. Some people feel tired, others feel energized.
What the Research Shows
The evidence base for somatic approaches is still growing, but early results are promising. A scoping review published in the European Journal of Psychotraumatology found large positive effects for Somatic Experiencing on PTSD symptoms, depression, and overall psychological well-being across multiple studies. In one study of tsunami survivors, 90% showed partial or full reduction in reported symptoms at follow-up assessments.
A broader systematic review of somatic interventions for PTSD found improvements ranging from about 44% to 90% across different studies, with Somatic Experiencing and related bodywork approaches often performing at the higher end. One study with veterans showed roughly a 50% reduction in PTSD symptoms over nine weekly sessions. Another found a 53% improvement in PTSD severity based on self-reports. At longer follow-ups of four weeks to eight months, improvement rates climbed to 75% and 85% respectively.
One thing worth noting: studies on vibration-based interventions have not found measurable changes in cortisol (the body’s primary stress hormone) in healthy young women, even after 12 weeks of regular sessions. This suggests the benefits may work through nervous system regulation and muscular release rather than directly lowering stress hormones in the bloodstream. The mechanism isn’t fully understood yet.
How a Typical Session Works
A TRE session usually takes 15 to 30 minutes. You start with a series of exercises that tire out the legs and hips: wall sits, forward bends, wide-legged squats, and similar movements. These aren’t intense workouts. They’re designed to create just enough muscle fatigue to activate the tremor reflex. Once you lie down with your knees bent and feet together (a butterfly position), the shaking usually starts on its own within a few minutes.
Beginners are generally advised to keep tremoring sessions short, around 10 to 15 minutes, and practice two to three times per week rather than daily. The reasoning is that releasing too much too quickly can feel overwhelming, especially for people with a significant trauma history. Over time, many practitioners extend their sessions or find the tremoring activates more easily without the warm-up exercises.
Somatic Experiencing sessions are different. They’re typically guided by a trained practitioner who helps you track physical sensations in your body, notice where tension lives, and allow small releases (including shaking and tremoring) to happen gradually. This approach emphasizes “titration,” meaning you process small amounts of stored stress at a time rather than opening the floodgates all at once.
Risks and Limitations
Somatic shaking is generally low-risk for most people, but it’s not without caution. The biggest concern is what trauma therapists call “flooding,” where too much stored emotion or sensation surfaces at once, leaving you feeling overwhelmed, dissociated, or more anxious than when you started. This is more likely if you have a history of complex trauma, PTSD, or dissociative episodes.
For people with significant trauma histories, working with a trained practitioner, at least initially, is a safer approach than trying to guide yourself through intense tremoring alone. The practitioner’s role is essentially to help you stay within a manageable window of sensation, slowing things down when the release gets too intense and helping you stay grounded in the present moment.
People with certain physical conditions, including recent surgeries, hernias, or spinal injuries, should also be cautious with the exercises that trigger tremoring, since they involve deep core and hip muscles. Pregnancy is another situation where the deep psoas engagement warrants extra care.
Somatic Shaking vs. Other Body-Based Practices
Somatic shaking occupies a specific niche in the broader landscape of body-based stress relief. Yoga has shown roughly 60% reduction in PTSD symptoms across several reviews, working through a combination of movement, breathwork, and mindfulness. Somatic Experiencing and related approaches tend to show slightly higher improvement rates in the studies that exist, between 80% and 90% in some cases. A combination of mindfulness and meditation practices showed about 84% improvement in one study.
The key difference is that somatic shaking focuses specifically on involuntary movement. You’re not stretching, posing, or consciously directing your body. You’re triggering a reflexive process and then getting out of the way. For people who find it hard to sit still in meditation or who feel disconnected during yoga, this can feel more accessible because the body essentially does the work.