Sitting balance, defined as the ability to maintain the body’s center of mass over the base of support while seated, is a foundational skill for individuals with a spinal cord injury (SCI). The loss of muscle control in the trunk, hips, and pelvis following an SCI makes maintaining a stable seated position challenging, especially for those with cervical or high thoracic injuries. Developing this control is fundamental for regaining independence, as many daily activities are performed from a seated posture. A strong, stable trunk provides the platform necessary for the arms and hands to move freely and effectively, which is key to functional mobility.
Why Sitting Balance is Crucial After Spinal Cord Injury
Developing robust sitting balance directly translates into greater functional independence in daily life activities (ADLs). Without this stability, simple tasks like reaching for a cup or adjusting clothing can cause a person’s center of gravity to shift outside their base of support, leading to a loss of balance. The ability to control the trunk significantly improves the safety and ease of transfers, such as moving from a bed to a wheelchair or in and out of a car.
A stable core is also important for performing self-care tasks like dressing and grooming, allowing the person to manipulate clothing or reach their feet without falling. Furthermore, a strong trunk contributes to better respiratory function by promoting upright posture, which allows the diaphragm and chest wall muscles to work more efficiently. Improved sitting balance also reduces the risk of falls from the wheelchair.
Foundational Principles and Safety Considerations
Before beginning any sitting balance program, consult with a physical therapist to ensure the exercises are appropriate for the specific level of injury and current physical capabilities. The initial setup must focus on establishing a secure base of support, which means sitting on a firm, non-slip surface, such as a mat table or a stable wheelchair. Practicing on a soft surface like a bed is generally not recommended for initial training, as it creates too much instability.
Proper starting posture involves aligning the spine neutrally and pulling the shoulders back to establish an upright position. Feet should be flat and positioned to help stabilize the lower body, though this may not be possible for all injury levels. A spotter must be present, especially when first attempting unsupported sitting, to prevent falls and provide immediate assistance if balance is lost.
Several contraindications and precautions must be observed during training. Any new or increasing pain or dizziness requires an immediate stop to the exercise session. Skin integrity must be checked before and after each session due to the risk of pressure injuries from prolonged sitting, paying close attention to areas like the sacrum and ischium. Individuals with high-level SCI should also be aware of the signs of autonomic dysreflexia, which can be triggered by discomfort or pressure during exercise.
Static Trunk Control Exercises
Static trunk control exercises focus on building the endurance and stiffness required to hold a steady, upright position without external support or movement. The first step is unsupported sitting, which involves gradually reducing reliance on the hands for support (moving from hands-behind the hips, to hands-by-the-sides, and finally to hands-in-lap). The goal is to progressively increase the duration of hands-free sitting, starting with short bursts and building up to 30 seconds or longer.
Integrating breathing techniques is important for static control, as the diaphragm and deep abdominal muscles play a role in core stability. Practicing diaphragmatic breathing—deep inhales that expand the belly, followed by controlled exhales—helps to engage the deep core musculature. Once unsupported sitting is achieved, the next progression is adding a small change to the center of gravity, such as performing a Trunk Hold with Arm Elevation.
For this exercise, the person maintains a stable trunk while slowly lifting one or both arms straight out in front or overhead, which immediately shifts the body’s weight and challenges stability. A more advanced static hold is the Side Leaning Hold, where the person intentionally sustains a lean to one side or the other, often using a spotter or a wall for initial safety. This movement strengthens the lateral trunk muscles and simulates the stability needed to reach to the side without falling.
Dynamic Weight Shifting and Reaching Drills
Dynamic weight shifting and reaching drills advance the training by requiring controlled movement outside the base of support, mimicking real-life tasks. These exercises require the trunk muscles to react and adjust to changes in the body’s center of mass, rather than just holding a static position. Controlled Reaching is a foundational dynamic drill that involves reaching forward, diagonally, and to the side, gradually increasing the distance of the reach.
The key to controlled reaching is initiating the movement from the trunk, allowing the body to lean in a controlled arc, and then smoothly returning to the center position. Weight Shifts are performed by deliberately shifting the weight from one buttock to the other, or from the back of the seat to the front, which is necessary for pressure relief and transfers. This movement should be performed slowly to ensure the trunk muscles are actively controlling the shift.
Trunk Rotation is introduced by twisting the upper body to look or reach behind the chair, integrating rotational stability into the core control program. A functional way to practice both reaching and rotation is through Ball Catching or Tossing, where the unpredictable nature of catching a ball forces the trunk to rapidly adjust and stabilize. For all dynamic drills, start with small, slow movements and only increase the range of motion or speed once the movement can be performed with consistent stability and control.