The core of your body or trunk is an area that does a lot of work but is often underrepresented. That is changing as more treatments for paralysis are being implemented in general rehabilitation settings. The torso, trunk or core provides the bulk of the work in holding the body up. It is flexible for allowing movement.

Knowing the levels where your trunk functions can help you understand your abilities and cautions. Like the rest of your body, the trunk is divided into dermatomes for sensation and levels for function. The trunk is unique to other body parts like the arms and legs because it functions mostly as one unit. Arms and legs have joints that allows a variety of movement. Flexibility of the arms and legs provides a clear visual of function. The one unit of mass of the trunk does not allow for specific level functions to be discriminated.

To understand your trunk, a medical assessment of movement and sensation is done. More easily, you can assess your level of injury and sensations. This is done by a ‘two finger’ measurement. Using your index and middle finger together, place your fingers at the natural nipple line on the trunk. You need to begin at the natural nipple line for effective measurement. Sometimes individuals have dependent skin, which can be lower than the natural line. The natural nipple line is Thoracic level 4 or T4. T4 is the first spinal cord level that solely serves the trunk. Two fingers above the natural nipple line are T3 that includes part of the underarm.

Going down the trunk, use the two-finger measurement from the bottom of where your measured T4, two fingers down is T5, from the bottom of T5 is T6. Continue down until you reach the natural line of the belly button, which will be T10. Right below the belly button at T10 is T11, followed by T12. Abdomens are of varying sizes, so some belly buttons might be shifted due to extra tissue. Use the width of your own fingers for your body size. A person doing this assessment who is of a smaller or larger frame may not have the same bone structure as your body.

The two-finger measurement is a non-scientific assessment. It is simple and requires no equipment. A lot of information is provided to know about where your injury is, your sensation, and where there is feeling or numbness (better known as the transition zone).

Individuals with spinal cord injury, multiple sclerosis, ALS, or other diseases or injury can have their trunk affected. The trunk serves as the core of the body, containing all the vital organs, except the brain, and with the head, arms and legs branching off from it. The trunk provides muscular support for holding up the body. Most importantly, it provides the sensory function to let the brain know where the body is in space. This means it lets the brain know if you are laying, sitting, or standing. It can let the brain know if you are falling or bending. Without the sensory input of body positioning (proprioception) and balance (equilibrium), your brain does not know if you are in a safe position.

There are some exercises that you can do to help build your trunk muscles. The best thing about these exercises is that not only do they help trunk control but also serve other improvements to the body.

Deep breathing exercises are known to help improve lung function, but as you are expanding your lungs, you are also exercising your chest wall muscles, making them stronger. You can deep breath using your muscles or use the sigh feature if you are ventilatory dependent. If you have use of your stomach muscles, you may be able to access these muscles when deep breathing.

The use of an incentive spirometer helps to control the time and length of your breath. Doing this exercise in three cycles twice a day is a basic start. If you do not have an incentive spirometer, start with a large diameter smoothie straw to draw in air. Over time, move to a fast-food size straw with a large diameter, then to a smaller diameter straw, finally to a coffee stir straw which is really small in diameter. Go slowly over months. Never make yourself self-lightheaded or dizzy. This is a pleasant exercise, not a punishing challenge.

Coughing clears the airway but also stimulates the same muscles as deep breathing. This can be a far more forceful challenge. Cough on your own or with the assist of the cough feature if you are ventilatory dependent. A good time to cough is whenever needed, moving to an upright position or at selected times during the day. This helps to clear the lungs as well as use your chest muscles.

Pressure releases are very effective movements for improving your trunk strength. Many individuals perform wheelchair pushups for pressure release. This builds strength in your arms as well as stretching movement to your abdominal muscles. Others will use the tilt in space feature on a power chair. This also stretches muscles in the trunk. Because you are lifting and shifting your body, your muscles are being moved in your trunk. Rolling or being rolled from side to side in bed is a start.

Another way to release pressure when sitting is by leaning forward or having someone lean your body forward in your chair. This can be a safety issue due to challenges with proprioception; therefore, always have someone help or be in front of you, so you do not topple out of the chair. Draping your upper body over each side of the chair does the same. Practice with a person monitoring for safety until you have this mastered. Not only does pressure releases help your skin and trunk muscles, but it is also good to help stimulate the abdominal muscles for bowel function and stir up urine in the bladder.

Range of motion or stretching is movement provided to every part of the body. If your spine is stable, gently and slightly stretching your trunk forward and back when side lying in bed or side to side is trunk exercise. This stimulates the muscles that are being moved, but when you move your legs and arms, those muscles are connected to the muscles in your trunk. The movement of one set of muscles stimulates some movement in the adjoining trunk muscles. You get the benefit of movement of your extremities with the bonus of trunk muscle stretching. Exercise of pelvis floor muscles can improve continence but also stimulate abdominal muscle for trunk control.

Some individuals use braces or other assistive devices for walking, which is great trunk exercise. However, some individuals find these can be cumbersome for everyday use. If you choose not to use them for everyday walking, be sure to use them as an exercise on a daily basis.

In therapy, you may be provided with more movement to the trunk. Depending on safety, you can continue these exercises at home with someone assisting you or on your own. Reaching for items and ball tosses are ways to engage arm movement and trunk movement in unison. Rotation exercises of the trunk can be done if the spine is stable. Sitting exercises and challenges can also be beneficial to the trunk if safely performed. Increasing intensity is added with therapeutic bands, weights, and balance balls. Isometric exercise also has benefits.

Electrical stimulation on the skin is direct stimulation of the muscles and nerves below the skin surface. This is becoming more common in traditional therapy. If you have not tried this treatment, you can obtain access in your two weeks per year of mobility training that is offered by most payors. During the two weeks, which can be spread out into a treatment per week, you will learn how to use the device and the process so you can continue with stimulation at home.

Adding biofeedback improves your exercise routine. The use of skin surface receptors can help you visualize muscles that are contracting and relaxing if you cannot feel them doing so. You can then relate your actions to know that you are stimulating different muscles in your body.

Transcranial magnetic stimulation is a newer but established technique where areas of the brain and now spinal cord, are stimulated to create muscle responses in the body. This technology is new, so finding a provider can be a challenge. More of this type of treatment will be forthcoming.

Opportunities for improving trunk control are abundant regardless of your level of injury. Do not overlook this part of your body. It is the core of all movement. Nurse Linda

Pediatric Consideration:

If you use the two-finger assessment for the location of spinal levels and sensation on a small child, remember the two-finger width should be equivalent to the child’s fingers, not yours as an adult.

Trunk control is essential for mobility at all ages. However, the exercises should be age-appropriate. For example, sitting is not a developmental step for an infant, so age-appropriate activities should be used. Progressing the child within the developmental levels for cognition and physical status with adaptions as necessary is a good guide. Also, within the progressive plan for mobility and trunk control, musculoskeletal development should be included to ensure the body is growing and forming. Exercises that push the developing body too far can lead to complications. Not exercising also has complications as muscles can develop at different rates on each side of the body.

Follow the directions of your child’s healthcare professional to ensure a plan is in place for your child’s specific needs. This should be carried out at home as well as at school. Use the Individual Education Plan (IEP) process to be sure your child’s physical needs are addressed and appropriate. Nurse Linda

Linda Schultz is a leader, teacher, and provider of rehabilitation nursing for over 30 years. In fact, Nurse Linda worked closely with Christopher Reeve on his recovery and has been advocating for the Reeve Foundation ever since.

In our community, Nurse Linda is a blogger where she focuses on contributing functional advice, providing the "how-to" on integrating various healthcare improvements into daily life, and answering your specific questions. Read her blogs here.

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