Studies have shown that 2.3 to 3.6 of 1,000 children born in the United States have cerebral palsy. Moderate to severe cerebral palsy is defined as Gross Motor Function Classification System (GMFCS) levels III to V. Level III is defined as being able to walk with assistive devices and requiring a wheelchair outdoors and in the community, level IV is defined as self-mobile in a wheelchair with limitations, and level V as very limited in self-mobility even with assistive technology.1 These children are susceptible to many illnesses and medical complications throughout their lives, which may lead to a shortened life expectancy.
Many therapists are aware of the impact of standing programs on range of motion and bone density, but a consistent standing program also supports respiratory development, positively affecting respiratory health throughout the lifespan.
Forty-two percent of children who were classified as level IV and used a feeding tube had respiratory problems; 23 percent in level V who did not have a feeding tube had respiratory problems. Nine percent of children in level IV and 15 percent in level III had respiratory problems.2
Maudsley, Hutton and Pharoah in 1999 reported that in the United Kingdom from 1966 to 1991, 37 percent of children with cerebral palsy died as a result of viral or bacterial pneumonia, and 27 percent died as a result of acute upper respiratory illnesses such as bronchitis, bronchiolitis or as a result of pneumonia due to aspiration of foods, liquids or secretions.3
Typical Chest Development
In a typically developing child, significant changes in chest wall shape and respiratory efficiency occur between the ages of 6 months and 12 months when the child begins to assume upright positions. In a vertical position, the child effectively strengthens the abdominal musculature.
The increase in muscle strength, combined with the effects of gravity, exert a downward pull on the ribs, opening the intercostal spaces and effectively optimizing the length-tension relationship of the diaphragm and intercostals. The newfound length in these muscles enables them to contract more easily and with greater force, resulting in increased chest excursion in anterior-posterior, superior-inferior and transverse planes.
The development of the diaphragm, abdominal muscles and intercostals provides stability to the viscera and chest wall as intra-abdominal and intrathoracic pressures inversely oscillate between phases of respiration.
Total lung volume increases fourfold, and the size of the conducting airways increase threefold.4 Increases in inspiratory and expiratory reserves and increased tidal volume support the child as activity levels rise.
Atypical Chest Development
Children with moderate to severe cerebral palsy have significant trunk muscle weakness and muscle tone imbalance. Their functional antigravity muscle strength and motor control are compromised, frequently resulting in increased time spent in supported supine positions. The floor acts as a stabilizing force on the ribcage, prohibiting it from a typical pattern of expansion, most notably in the anterior-posterior plane.
Further exacerbating the problem is the effect of abdominal muscle weakness on the position of the ribs. The abdominals lack the strength to effectively rotate the ribs downward, leaving the intercostals and diaphragm in shortened positions and resulting in a reduced rib cage size relative to the size of the trunk.
These children are typically restricted in both anterior-posterior and superior-inferior rib cage expansion, allowing predominant lateral rib movement during respiration. This decreases tidal volume and respiratory reserves, resulting in poor secretion clearance and requiring an increase in respiratory rate.
The aforementioned deficits in respiratory muscle strength in children with moderate to severe cerebral palsy significantly increase their susceptibility to respiratory disease. Shallow, irregular respiration combined with decreased efficiency and poor coordination of the breathing mechanisms jeopardize ventilatory capacity. A compounding risk factor for respiratory disease is the reduced level of physical activity present in this population as a result of impaired neuromotor control.5
Decreased range of motion in the thorax and shoulder girdle results in increased work to maintain adequate ventilation. Many of these deficits can be addressed with the aid of positioning devices to develop an upright positioning routine.
Standing for Respiratory Health
A positioning and strengthening program is important for children with compromised respiratory status. Children with limited movement are at risk for chest complication because of chest wall biomechanics, feeding difficulties, immobility and poor coughing abilities. Regular placement in an upright position can contribute to pulmonary health.6 A strengthening program may include progressive resistive exercise, isometric exercise and use of isokinetic devices.7
Supported standing for children with moderate to severe cerebral palsy is a form of exercise and has been shown to improve strength and endurance and these in turn will result in improved respiratory health.
Standing has been shown to improve lung capacity. In addition, studies have shown that those who stand frequently have lesser or delayed occurrence of respiratory complications and improved respiratory volume. Standing can also help to reduce chest congestion and coughing.8
The increased extension of the upper trunk that occurs when positioned in a stander reduces pressure on internal organs, thus enhancing respiratory capacity and the ability to function. A standing program can prevent many of the complications often seen in children who use wheelchairs for mobility.
Respiratory problems can cause numerous hospitalizations for children with moderate to severe cerebral palsy. Maintaining a healthy respiratory status should be a top priority for this population.9 Physical therapy is an important component in assisting children with moderate to severe cerebral palsy to maintain their respiratory health.
Physical therapists can provide evaluation and recommendations for home standing programs using an appropriate assistive device. A standing program should be considered an essential preventive strategy. It is less expensive than a more passive or reactive approach to dealing with respiratory complications and should lead to greater health for children with cerebral palsy.9
There have been few studies done that look at improving cardio-respiratory fitness in children with cerebral palsy, but preliminary results indicate that gains are possible with the use of a strengthening program such as one that includes standing.
Respiratory health is essential for functional abilities and quality of life for children with moderate to severe cerebral palsy. The leading cause of death for these children is respiratory-related. It has been scientifically demonstrated that children with cerebral palsy have the potential to improve their respiratory function through exercise, but options for exercise through movement are limited for these children.
A regular standing program has been proven to improve measures of respiratory function, leading to decreased incidence of illness and should be a daily part of life for children with moderate to severe cerebral palsy. Further research must be performed that will allow us to improve our ability to intervene and to decrease disease, prevent secondary health complications and enhance the quality of life in children with cerebral palsy.
1. Liptak, G., O'Donnell, M., et al. (2001). Health status of children with moderate to severe cerebral palsy. Developmental Medicine & Child Neurology, 43, 364-370.
2. Maudsley, G., Hutton, J., & Pharoah, P. (1999). Cause of death in cerebral palsy: A descriptive study. Archives of Disease in Children, 81, 390-394.
3. Massery, M. (1991). Chest development as a component of normal motor development: Implications for pediatric physical therapists. Pediatric Physical Therapy, 3(1), 3-8.
4. Shaffer, T., Wolfson, M., & Bhutani, V. (1981). Respiratory muscle function, assessment and training. Physical Therapy, 61, 1711-1723.
5. Campbell, S., Vander Linden, D., & Palisano, R. (2006). Physical Therapy for Children, Third Edition. Lyme, CT: Greenwich Publishing Group.
6. Tecklin, J. (1981). Physical therapy for children with chronic lung disease. Physical Therapy, 61, 1774-1782.
7. Arva, J., Paleg, G., et al. (2009). RESNA Position on the Application of Wheelchair Standing Devices. Assistive Technology, 21, 161-168.
8. Massery, M. (1994). What's Positioning Got to Do With It? Neurology Report, 18(3), 11-14.
9. Fowler, E., Kolobe, T., et al. (2007). Promotion of physical fitness and prevention of secondary conditions for children with cerebral palsy: Section of Pediatrics Research Summit Proceedings. Physical Therapy, 87, 1495-1510.
Carol Gilligan, Lindsey Hulit-Harrigan and Jenny Sargent are all physical therapists at Kids Abilities, established in January 2000 in Shoreview, MN, and Hugo, MN, with a third location opening in Indianapolis. Kids Abilities offers physical, occupational and speech therapies, serving clients from birth to young adulthood with diagnoses including cerebral palsy, spina bifida, brain injury, Down syndrome and autism disorders. Together the authors have more than 40 years of experience.