Static and dynamic balance of the trunk in adolescent idiopathic scoliosis

Transcription

1 Static and dynamic balance of the trunk in adolescent idiopathic scoliosis I. Aprile 1, S. Marcandelli 2, G. Russo 1, C. Simbolotti 1, C. Garattini 1, F. De Santis 1 e L. Padua 1, 3 1 Don Carlo Gnocchi Foundation, Rome-Italy 2 Tecnobody, Bergamo-Italy 3 Institute of Neurology, Università Cattolica del Sacro Cuore, Rome-Italy iaprile@dongnocchi.it

2 .literature Decreased standing stability at the onset of AIS. (Sahlstrand et al, 1978, Byl and Gray, 1983; Herman 1995) The spinal deformity not only modifies the shape of the trunk, but also changes the relations between body segments (Sawatzky B, 1997; Stokes, 1994) Postural alterations in the orientation of the head, shoulders, scapula, and pelvis in all three planes, but more particularly, rotations of body segments in the horizontal plane (Le Blanc et al. Res Spinal Deform 1997)

3 THE POSTURAL STABILITY CONTROL AND GAIT PATTERN OF IDIOPATHIC SCOLIOSIS ADOLESCENTS. Chen PQ, Wang JL, Tsuang YH, Liao TL, Huang PI, Hang YS. Section of Spinal Surgery, Department of Orthopedic, National Taiwan University Hospital, Taipei, Taiwan, ROC. Clin Biomech 1998;13(1 Suppl 1): S52-S58. Lower postural stability in scoliosis adolescents than control OBJECTIVE: The static postural equilibrium and gait patterns between idiopathic scoliotic (IS) patients and normal subjects were studied to verify the best method to identify the functional disability in IS patients. DESIGN: The static stability in six postures and gait patterns among normal subjects and IS patients were compared. BACKGROUND: Postural stability control and gait analysis are noninvasive methods to identify many diseases. However, the dysfunction of IS patients in postural stability control and gait pattern is not clear. The results of this research may lead to further understanding of the etiology of idiopathic scoliosis in the postural equilibrium influencing aspects. METHODS: Thirty IS patients and fifteen normal subjects were recruited for postural stability control test and gait analysis using the force plate and 3-D motion analysis system. RESULTS: The IS patients generally produced higher sway area, lateral sway, sagittal sway, and sway radius than normal subjects. The cadence is smaller in the IS patients, but the stance phase and stride phase are similar to normal subjects. CONCLUSIONS: The IS patients are poor in postural stability control but their gait pattern is similar to that of normal subjects. Standing with trunk at full flexion is the most effective position to identify the postural stability control of IS patient.

4 Spine ;24(2): Subjects leaned laterally and, in general, anteriorly, in all test postures. The direction of lean from standing to sitting varied depending on whether the spinal curve was single or double, thoracic or lumbar THE SPINAL CURVE IN STANDING AND SITTING POSTURES IN CHILDREN WITH IDIOPATHIC SCOLIOSIS Gram MC, Hasan Z. Department of Physical Therapy, College of Health and Human Development Sciences, University of Illinois at Chicago, USA. STUDY DESIGN: A sample of convenience of children with moderate idiopathic scoliosis without bracing or surgery was studied. The sample consisted of 19 children, aged 9 to 16 years, with mean Cobb angle of 24 degrees. The spinal configurations and paraspinal muscle activity in several commonly assumed postures were examined. OBJECTIVES: To determine how the apex angles, verticality of spine, and muscle activity vary with the assumed posture and whether the location and the number of spinal curves affect these variables. SUMMARY OF BACKGROUND DATA: It has been suggested that the configuration of the spine in commonly assumed postures can affect the spinal curve in scoliosis because of gravitational bending moments. There is, however, a paucity of data obtained in subjects in sitting postures that school-age children assume daily for prolonged periods. Absence of bilateral symmetry in pressure during sitting has been described, but its effect on the spinal apex angle has not been investigated. METHODS: Infrared-emitting markers, whose three-dimensional positions could be tracked by a pair of cameras, were affixed to the spine. The natural postures studied were relaxed standing, relaxed sitting, erect sitting, and writing while seated. Electromyographic activity in muscles close to the spinal apexes was recorded bilaterally for each test posture. RESULTS: Subjects leaned laterally and, in general, anteriorly, in all test postures, rather than placing the C7 vertebra vertically above S1. The direction of lean and the change in the spinal apex angle from standing to sitting varied depending on whether the spinal curve was single or double, thoracic or lumbar. Subjects with single curves, whether thoracic or lumbar, tended to lean laterally toward the convexity of their curve apex--that is, the lean was in a direction that reduced the apex angle. Subjects with double curves (thoracic and lumbar), in all postures except relaxed sitting, tended to lean toward the convexity of the lumbar curve, thereby reducing the lumbar apex angle and exacerbating the thoracic angle. Most subjects' apex angles were smaller in relaxed or erect sitting than in relaxed standing. Electromyographic activity was in general greater on the convex side of the curve, with greatest activity in erect sitting. CONCLUSIONS: The findings indicate that in self-selected postures the gravitational effect of leaning and the muscle activity in paraspinal muscles may serve to reduce the apex angle. Thus, a fully upright, centered posture may not be best for correction of every patient's spinal curve.

5 Spine ;27(17): The scoliotic group was characterized by a decrease in standing stability RELATIONS BETWEEN STANDING STABILITY AND BODY POSTURE PARAMETERS IN ADOLESCENT IDIOPATHIC SCOLIOSIS. Nault ML, Allard P, Hinse S, Le Blanc R, Caron O, Labelle H, Sadeghi H. Department of Kinesiology, University of Montreal, Quebec, Canada. STUDY DESIGN: A retrospective study of standing imbalance and body posture in 71 able-bodied girls and subjects with adolescent idiopathic scoliosis was conducted. OBJECTIVE: To test the hypothesis that postural parameters are related to standing stability parameters. SUMMARY OF BACKGROUND DATA: Spinal deformity not only modifies the shape of the trunk, but also changes the relations between body segments affecting posture in scoliotic children. These postural adaptations to the scoliotic curve progression could be linked in part to increased body sway in upright standing. This has not yet been related to specific postural parameters involving the head, trunk, and pelvis in nontreated idiopathic scoliosis. METHODS: The head, trunk, and pelvis orientations of each subject were measured by a Flock of Bird system. An AMTI force platform was used to assess quiet standing stability and to monitor the position and displacement of the center of pressure (COP). The center of mass (COM) excursion was estimated from a biomechanical model using force plate information only. Analyses of variance (ANOVAS) were performed to determine the statistical differences between the scoliotic and nonscoliotic subjects, and backward stepwise multiple regression analyses were performed to identify any correlation between measures of quiet standing stability and body postural parameters RESULTS: The scoliotic group was characterized by a decrease in standing stability. There was an increase in the sway areas measured by the variations of the COP and COM. From the backward stepwise multiple regression analysis, it appears that for the able-bodied girls, the body posture parameters were correlated only with the mean anteroposterior center of pressure (COP(AP)) position. For the scoliotic group, the sway areas and the mean position of the centers of pressure and the COP(AP)-COM(AP) were correlated significantly with body posture parameters. The higher COP-COM differences for the scoliotic group were attributed to a greater neuromuscular demand to maintain standing balance. The coefficients of correlation of the multiple regression analyses ranged from 0.64 to 0.85 for the nonscoliotic group and from 0.55 to 0.72 for the scoliotic group. CONCLUSIONS: The use of backward stepwise multiple correlations highlighted the interaction between several body parameters and their relation to standing stability in both able-bodied girls and scoliotic subjects. The scoliotic group displayed a much larger number of correlations between standing stability and body posture parameters than the nonscoliotic group. Standing imbalance was related to altered body posture parameters measured in the frontal and horizontal planes only. Although the correlation coefficients were relatively high, factors other than body posture parameters appeared related to standing imbalance in adolescent idiopathic scoliosis. These findings support the concept of either a primary or a secondary dysfunction in the postural regulation system of scoliotic subjects.

6 Spine ;29(20):E This was the first study to explore a sitting posture in adolescents with scoliosis SEATED POSTURAL CONTROL IN ADOLESCENTS WITH IDIOPATHIC SCOLIOSIS Bennett BC, Abel MF, Granata KP University of Virginia, Charlottesville, VA, USA. bcb3a@virginia.edu STUDY DESIGN: The center of pressure (COP) path in 14 adolescents with idiopathic scoliosis and 12 age-matched able-bodied adolescents was compared using traditional measures and a two-level decomposition. OBJECTIVES: To investigate whether asymmetries in the spines of children with idiopathic scoliosis are reflected in altered sway patterns in quiet sitting. SUMMARY To eliminate OF BACKGROUND any contributions DATA: Previous from ankle studies muscles have studied and the gain sway of greater children insight with scoliosis into while how standing. the use However, of trunk the muscles standing posture would is affect typically the control controlled of posture, at the ankle we joint. studied To date, the there movement are no studies of with the this center population of sitting sway, where the movement is controlled by the trunk of pressure (COP) of the upper body of children while seated muscles. METHODS: Traditional measures of the COP of the trunk were analyzed. The COP was also decomposed into an approximation of the center of mass path and deviations around this path. RESULTS: COP movement in sitting, reflecting the postural control of the spine, was decreased in adolescents with idiopathic scoliosis. Children with scoliosis had symmetric sitting COP trajectories and most measures were similar between the two groups. CONCLUSIONS: The results suggest a control strategy for maintaining a sitting posture that does not change with the development of scoliosis but does adapt by decreasing movement to maintain the trunk in a region where the it can remain "passively" stable. Balans style chair mounted on a 6 degree of freedom force plate

7 First hypothesis: a greater asymmetry in the sway trajectory of children with scoliosis Second hypothesis: False a smaller amplitude of sway of children with scoliosis True the reduced COP movement is a reflection of reduced mobility of the torso, it could be associated with larger motions of the COP while standing Need to study sway in situations where the stability of the trunk is challenged. Bennett BC, 2004

8 Bennett BC, 2004

9 Aims of our study Static balance of the trunk in sitting Dynamic balance of the trunk in sitting

10 Prokin B line- Tecnobody

11 In all subjects the evaluation of the trunk in sitting position was performed in two conditions: static and dynamic condition Static balance of the trunk Dynamic balance of the trunk Prokin B + Trunk Seat / Prokin M line - Tecnobody

12 Dynamic parameters: ATE%: movement precision VFM: force-costancy applied Dynamic balance evaluation of the trunk was performed following a cycling path Propriocective stool Prokin M line- Tecnobody

13 Sample Scoliosis patients (15-50 Cobb) Controls n 15 cases with a single curve n 12 cases with a double curve n 10 controls

14 Sample Patients and controls are comparable Patients Controls p-level N M/F 2/27 1/10 - Age 14.1 (1.7) 17.7 (6.1) NS Weight 52.1 (8.7) 49.6 (12.7) NS Height (7.2) (10.2) NS

15 Open eyes COMPARAZIONE perimetro ed area (OA) PERIM. (mm) p<0.05 AREA (mm2) CONTROLLI SCOLIOSI In standing position patients have higher CoP area than controls

16 scoliosis normal

17 Open eyes COMPARAZIONE perimetro ed area (OA) 100,0 80,0 60,0 40,0 CONTROLLI SCOLIOSI 20,0 0,0 PERIM. (mm) AREA (mm2) Static evaluation Closed eyes COMPARAZIONE perimetro ed area (OC) In sitting position no significant differences between scoliosis patients and controls are observed in CoP area and in CoP sway 80,0 60,0 40,0 20,0 0,0 PERIM. (mm) AREA (mm2) CONTROLLI SCOLIOSI

18 scoliosis normal

19 Dinamic evaluation ATE % Comparazione ATE tra controlli e pazienti p<0.05 A.T.E. in % significant increase of the ATE % (p<0.05) in scoliosis subjects with respect to healthy subjects scoliosis adolescents had a reduced movement precision following the cycling path controls Controlli Scoliosi patients campione Media ±ES ±DS Outlier

20 Dinamic evaluation 1,8 1,7 VFM Comparazione V.F.M tra controlli e pazienti p=0.02 1,6 1,5 V.F.M. 1,4 1,3 1,2 1,1 1,0 significant increase of the VFM (p<0.05) in scoliosis subjects with respect to healthy subjects 0,9 0,8 scoliosis adolescents had a reduced force-constancy applied following the cycling path controlli controls campione scoliosi patients Media ±ES ±DS Outlier

21 normal scoliosis

22

23 Dynamic evaluation of the trunk showed a significant increase of the ATE% (p<0.05) in subjects with scoliosis with respect to healthy subjects. When we compared the results obtained from patients with a single curve and from those with a double curve the ATE% was higher in the scoliosis with a single curve (p<0.05) A.T.E. in % normal single curve double curve Media ±ES ±DS Outlier

24 Movement precision during dynamic test is significantly relate to the CoP of the trunk proiection on Y axis Scatterplot (paz e controll comparabili.sta 64v*37c) A.T.E. in % = 39,822+0,2695*x p<0.05; r: 0.5 A.T.E. in % Y C.o.P. medio OE TRUNK

25 CoP of the trunk distribution on the X and Y axis (normal, single, double curve) X C.o.P. medio OE TRUNK X Axis Open eyes 8 Distribuzione del CoP TRONCO asse delle X controlli scoliosi doppia scoliosi normal single double campione - Media ±ES ±DS Outlier + X C.o.P. medio CE TRUNK Box Plot (campione ridotto solo scoliosi.sta 68v*153c) normal single double classificazione Closed eyes Media ±ES ±DS Outlier 40 Distribuzione del CoP TRONCO asse delle Y 40 Box Plot (campione ridotto solo scoliosi.sta 68v*153c) Y C.o.P. medio OE TRUNK Y Axis Y C.o.P. medio CE TRUNK controlli scoliosi doppia scoliosi normal single double campione Media ±ES ±DS Outlier normal single double classificazione Media ±ES ±DS Outlier

26 Conclusions Static balance of the trunk is not different in healthy adolescents and in patients with scoliosis (and in adolescents with a single and with a double curve) Dynamic balance of the trunk is lower in adolescents with scoliosis with respect to healthy subjects. If we consider only adolescents with scoliosis, the dynamic balance is more involved in patients with a single curve. Significantly CoP of the Trunk displacement on the Y axis in scoliosis adolescents

27 Conclusions In other words, adolescents with scoliosis, and mainly adolescents with a single curve, covered the cycling path on the propriocective stool, with lower precision and force-costancy than that of the healthy subjects The rehabilitation program should be focused on dynamic training of the trunk in scoliosis adolescents

28 acknowledgements Prof. Fabio De Santis Prof. Luca Padua Dott. Fabio Savi Physiotherapists Maria Teresa Vincenzi Patrizia Silvestri Neurophysiological Technicians Giusy Russo Chiara Simbolo8 Claudia Gara8ni Dott. Stefano Marcandelli (Technobody) Vittorio Chini (Endomedica)