Abstract
Effects of load carriage on postural balance and muscle activity in people with adolescent idiopathic scoliosis
Background: People with adolescent idiopathic scoliosis (AIS) have compromised postural balance and muscle symmetry. Load carriage, either symmetrical or asymmetrical loads, could further challenge these dysfunctions, and impact their musculoskeletal health.
Objectives: This cross-sectional comparative study aims to examine the impacts of load carriage on postural balance and muscle activity in individuals with AIS.
Method: Thirty females, 16 AIS with single right thoracic or thoracolumbar curves and 14 age-matched controls were recruited in this study. Postural balance parameters (centre of pressure, COP) and muscle bioelectrical activity of bilateral thoracic erector spinae (ES), internal oblique or transverse abdominis (IO/TrA) and lateral gastrocnemius (LG) were evaluated in four loading tasks at 5% of the subject's body weight including no load (NL), backpack load (BP), left shoulder load (LL) and right shoulder load (RL) in standing.
Results: AIS showed a significantly higher COP excursion in mediolateral direction under unilateral shoulder loading, however, between-group difference is found only in RL (mean: 7.98±1.22mm vs mean: 2.78±1.31mm; p=0.043). However, AIS showed generally higher right (convex-sided) activity during all tasks in ES, IO/TrA and LG. Higher right ES activity was observed with LL (p=0.002) and higher right LG activity was found with NL, BP and RL (p<0.05).
Conclusion: AIS demonstrates similar postural balance as controls, except when loading is on the convex-side shoulder. A consistent pattern of increased convex-sided paraspinal and calf muscle activity in AIS is revealed regardless of loading direction. This might indicate a stiffening strategy adopted by AIS and a tendency to lean towards the convex side for balance. With convex-sided loading, AIS shows decreased concave-sided muscle activity and inability to weight shift towards the concave side causing increased postural sway. Symmetrical loading, followed by asymmetrical loading on the concave side, is suggested for AIS to avoid postural deviation.
Background: People with adolescent idiopathic scoliosis (AIS) have compromised postural balance and muscle symmetry. Load carriage, either symmetrical or asymmetrical loads, could further challenge these dysfunctions, and impact their musculoskeletal health.
Objectives: This cross-sectional comparative study aims to examine the impacts of load carriage on postural balance and muscle activity in individuals with AIS.
Method: Thirty females, 16 AIS with single right thoracic or thoracolumbar curves and 14 age-matched controls were recruited in this study. Postural balance parameters (centre of pressure, COP) and muscle bioelectrical activity of bilateral thoracic erector spinae (ES), internal oblique or transverse abdominis (IO/TrA) and lateral gastrocnemius (LG) were evaluated in four loading tasks at 5% of the subject's body weight including no load (NL), backpack load (BP), left shoulder load (LL) and right shoulder load (RL) in standing.
Results: AIS showed a significantly higher COP excursion in mediolateral direction under unilateral shoulder loading, however, between-group difference is found only in RL (mean: 7.98±1.22mm vs mean: 2.78±1.31mm; p=0.043). However, AIS showed generally higher right (convex-sided) activity during all tasks in ES, IO/TrA and LG. Higher right ES activity was observed with LL (p=0.002) and higher right LG activity was found with NL, BP and RL (p<0.05).
Conclusion: AIS demonstrates similar postural balance as controls, except when loading is on the convex-side shoulder. A consistent pattern of increased convex-sided paraspinal and calf muscle activity in AIS is revealed regardless of loading direction. This might indicate a stiffening strategy adopted by AIS and a tendency to lean towards the convex side for balance. With convex-sided loading, AIS shows decreased concave-sided muscle activity and inability to weight shift towards the concave side causing increased postural sway. Symmetrical loading, followed by asymmetrical loading on the concave side, is suggested for AIS to avoid postural deviation.
Original language | English |
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Publication status | Published - 12 Nov 2023 |
Event | Pan-Pacific Conference on Rehabilitation - , Thailand Duration: 12 Nov 2023 → … |
Conference
Conference | Pan-Pacific Conference on Rehabilitation |
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Country/Territory | Thailand |
Period | 12/11/23 → … |