Damador G. Kamath, Sandy Armitage, Richard D. Beauchamp, Nalini Bhaskaranand, Madhu Manikanta, Radha Prabju

Proximal Stabilzation Centre

Surrey, B.C. Canada

V3S 3C1




Proximal Stabilization Therapy (PST) was developed to support the abdominal muscles dynamically in a program of progressively training children with CP in functional skills. After receiving PST for three to nine weeks, the ten children in this study showed significantly reduced spasticity, measured with ROM scores and indirectly through gait analysis. All subjects exhibited better antigravity security, reduced spacticity, and increased ROM and independence of movement at the end of the study. One child learned to walk independently, and two others learned to walk with assistance. The PST system appears to alter the natural history of the child, including the development of contractures and the need for surgery, seating systems and therapy.




Stabilizing the body proximally is fundamental to developing skilled movements in the distal musculature, postural control, and balance and coordination. Studies of proximally stabilizing children with CP noted that adaptive seating provides advantages for children with CP (2, 3, 4), including faster arm movement (5, 6), greater speech intelligibility and reduced hypertonicity (1).


Most studies have examined stabilizing the child in a static, seated position. Proximal Stabilization Therapy (PST) stabilizes the child using a dynamic support in a program of progressively training in functional skills. Clinical experience suggests that with PST, contractures were reversed or arrested; the children exhibited rapidly reduced spasticity and improved posture and balance; that they learned to walk without help, and to reach and grasp more effectively.


This study sought to determine whether PST effects functioning and spasticity, as indicated by joint range of motion (ROM) and footprint analysis.




Nine quadriplegics and one diaplegic between fifteen months and six years old were diagnosed and referred to therapists at K.M.C. Hospital, Manipal, India. All had received current therapy, none was ambulatory, had received surgery or used bracing. Children were selected by age, parental commitment and retardation level; no child that met the minimum criteria was eliminated. PST is most effective with hemiplegics when introduced between 12 and 24 months of age; for diaplegics and quadriplegics, between 15 and 36 months of age. One severely retarded child was included for comparison.


Randomness was limited by availability and by being referred to a hospital. We believe these limits to randomness are reasonable: parents deliver PST; it’s an educational program; being referred to a hospital is normal to the population who will use PST in the future. We did not create a control group because of finite resources, limited subject availability and variability among CP children.


Eight children were selected. We designed the study with three pretests at two-week intervals. Five subjects were withdrawn by the parents before the PST therapist arrived in India. Thus, we only have pretest scores for subjects 1, 4, and 7; none showed change of status during the pretest period.


During the first week of PST, parents were trained in using the equipment, goal setting and motivating their children to reach these goals. When the children felt at ease with the equipment, the parents provided two-hour sessions, twice daily. Parents then provided PST at home and returned to the hospital weekly for testing and help.


Separate therapists tested the subjects with Bayley’s Scales of Infant Development, with a structured video analysis of functionality, with a paediograph for gait analysis, with range of motion (ROM) measures, with a limb-load monitor to measure weight bearing on each foot, for grasp pressure, and for hand and feet temperature. The traditional paediograph was modified because of the expense of transporting materials from North America. Subjects walked along a specially designed tray, leaving footprints on a transparent plastic graph matrix. Therapists then copied the footprints onto a paediograph form for analysis. The analysis of the paediograph was also modified to specifically address changes in spasticity, as indicated on the graphs below. Heel-toe gait was defined as a complete footprint, even with metatarsal bars.


The first two data points and last two points were each averaged for each child to obtain scores that were less affected by temporary variations in performance. Each first and last average score was converted into a z score, used to measure change that is unaffected by the huge individual differences observed with CP and with young children. The differences between scores at the beginning and end of the study were compared with the Student’s t test.




Subject 1 (boy, 3 ¼ yrs.): Initially, unable to sit or roll onto left side; needed help to raise head; could reach with one hand. After PST, could sit in ambulatory with head up for 20 minutes, reach for toys with both hands, bear weight standing a few seconds with help. Also gained bowel control.


Subject 2 (boy, 5 ½ yrs.): Initially, musculature was flaccid; stayed in a fetal position; could not sit up, crawl, bottom scoot, or reach for toys. After three weeks of PST, toilet trained, could sit on a bench for 15 minutes, could bear weight with help balancing, started reaching for toys and playing.


Subject 3 (girl, 2.1 yrs.): Initially, rigid, exhibited constant involuntary movements; couldn’t sit, hold head up or turn it, use her hands. After three weeks of PST, could sit cross-legged, hold head up, turn it, and grasp. All involuntary movements stopped.


Subject 4 (boy, 2 ¾ yrs.): Initially, could only stand on toes, feet twisted in an inverted position; needed support to sit and stand. After five weeks of PST, could stand independently in the ambulatory, propel it forwards and backwards without tensing or inverting feet. His reach was more accurate.


Subject 5 (boy, 5 ½ yrs.): Initially, could sit briefly when propped in a corner, could stand or walk with extensive help, could not flex knees or lift legs while walking, supported himself on toes; seldom reached for toys. After five weeks of PST, could bend both knees in walking with minimal support from behind, shift weight and stand independently in the ambulatory, use both hands to reach, pick up toys more accurately and with less spasticity.


 Subject 6 (girl, 6 yrs.): Initially, could only pick up objects with toes, usually sat against a wall for security, could not stand; only moved by bottom scooting. After five weeks of PST, could stand alone, walk six steps without help, pick up objects with right hand, and transfer them to the left hand.


Subject 7 (boy, 2 ¼ yrs.): Initially, could stand alone for a moment, moved by bottom scooting, walk only with a held hand, used two-word phrases to communicate. After seven weeks of PST, could run, kick a ball, pick it up from a standing position, and join full sentences together in conversation.


Subject 8 (girl, 4 yrs., severely retarded): Initially, could sit and not ambulate at all. After PST, could stand and sit alone in the ambulator, and move it forwards and backwards.


Subject 9 (girl, 1 ½ yrs.): Initially, couldn’t stand or bear weight on feet. After five weeks of PST, could stand alone without ambulator for 15 minutes, walk with minimal help from behind, get up from the floor using only one hand, move from chair to chair.


Subject 10 (girl, 1 ½ yrs.): Initially, could sit, but not stand even assisted. After four weeks of PST, could get up from the floor using one hand, stand alone at a table, and take steps with help.


Statistically, the Student’s t test to analyze z scores indicates the significance of these improbable directional trends. Student’s t test to analyze z scores is only meaningful to the degree that other therapies do not achieve the same directional trends.


Figures 1 and 2 graph the increasing percentage of full foot prints over total foot prints on the left and right sides. The Student t test indicates statistical significance for the differences for both the average raw scores and the z score measure of change (p < 0.005 for both scores). Partial footprints are usually caused by spasticity in the heel cords.




Figure 3 graphs a decreased number of foot prints during the study, suggesting improved range of knee extension and decreased hamstring spasticity. Using the Student t test, the change was found to be not significant for the raw scores, but statistically significant for the z score (p < 0.005).



Figures 4 and 5 graph the increasing active hip flexion-extension range for both feet during the study. The Student t test found these changes to be statistically significant for both average raw scores and z scores (p < 0.005 for all four scores).






PST has been provided by our parents’ association for a decade. Our experience suggests that PST provides the benefits of adaptive seating without restricting breathing, walking and other movements. The health and functioning level of the whole body is enhanced. (Additional measures of improvement are show on a video about the Manipal study.)


Our system relies on parents to provide the therapy, since they have the best rapport and most time with their children. The effectiveness of PST appears to be proportional to parental commitment and subject intelligence, and inversely proportional to age.


Our experience suggests that other therapists using PST equipment need training in PST’s unique approach to test the complete PST program.




  1. Nwaobi, O.M. (1983) ‘Effects of Hip Flexion Angle on the Electrical Activity of the Hip Adductors in Cerebral Palsied Children’. Bulletin for Research (UTMB, Galveston) 3(1) 6.
  2. Nwaobi, O.M. (1986) ‘Effects of Body Orientation in Space on Tonic Muscle Activity of Patients with Cerebral Palsy.’ Developmental Medicine and Child Neurology, Vol. 28, pp. 41 – 44.
  3. Nwaobi, O.M., Brubaker, C.E., Cusick, B., Sussman, MD. (1983) ‘Electromyographic Investigation of Extensor Activity in Cerebral Palsied Children in Different Seating Positions.’ Developmental Medicine and Child Neurology 25, 175 – 183.
  4. Nwaobi, O.M., Trefler, E., Hobson, D. (1984) ‘Body Orientation in Space and Tonic Muscle Activity in Patients with Cerebral Palsy.’ Proceedings of the 2nd International Conference on Rehabilitation Engineering, pp. 481 – 483.
  5. Nwaobi, O.M., Hobson, D., Trefler, E. (1985) ‘Hip Angle and Upper Extremity Movement Time in Children with Cerebral Palsy.’ Proceedings of RESNA 8th Annual Conf., pp. 39 – 40.
  6. Seeger, B.R., Falkner, P., Caudrey, D.J. (1982) ‘Seating Position and Hand Function in Cerebral Palsy.’ Australian Occupational Therapy Journal, 29, 147 – 152.


We gratefully acknowledge the assistance provided by K. M. C. Hospital, Manipal, India and the Chris Spencer Foundation, Vancouver, B.C., Canada.