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Chapter Outline

Biomechanics of Sitting

  • Common Impairments in Sitting

Treatment Strategies for Improving Postural Control in Sitting

  • Motor Learning Strategies

Interventions to Improve Stability in Sitting

  • Varying UE and LE Support

  • Applying Resistance to Promote Stability

Interventions to Improve Dynamic Stability in Sitting

  • Sitting, Active Weight Shifts

  • Active Weight Shifts Against Resistance

  • Voluntary Movements and Task-Oriented Practice

  • Resisted Limb Movements

Interventions to Improve Transitional Mobility in Sitting

  • Scooting in the Short-Sitting Position

  • Scooting in the Long-Sitting Position

  • Scooting Off a High Table Into Supported Unilateral Standing

Interventions to Improve Balance Control in Sitting

  • Interventions to Promote Reactive Balance Control

  • Promoting Balance Control Using Mobile and Compliant Surfaces

  • Computerized Platform/Feedback Training

  • Ball Activities

  • Promoting Adaptive Balance Control

Seated Integrative Medicine Exercises

  • Seated Tai Chi

  • Seated Yoga

Outcome Measures of Sitting Ability


Student Practice Activities

This chapter focuses on sitting control and interventions that can be used to improve sitting and sitting balance skills. Careful examination of the patient’s overall status in terms of impairments and activity constraints that limit sitting control is necessary. This includes examination of musculoskeletal alignment, range of motion (ROM), and muscle performance (strength, power, and endurance). Examination of motor function (motor control and motor learning) focuses on determining weightbearing status, postural control, and neuromuscular synergies required for static and dynamic control. It also examines use of sensory (somatosensory, visual, and vestibular) cues for sitting balance control and central nervous system (CNS) sensory integration mechanisms. Finally, the patient must be able to safely perform functional movements (activities of daily living [ADL]) in sitting and in varying environments (clinic, home, work [job/school/play], and community).


It is important to understand the foundational requirements of sitting. Sitting is a relatively stable posture with a moderately high center of mass (COM) and a moderate base of support (BOS) that includes contact of the buttocks, thighs, and feet with the support surface. The pelvis is the foundation for sitting and strongly influences postural alignment of the entire axial skeleton. A neutral pelvic position is optimal for sitting. This is characterized by (1) an anterior superior iliac spine (ASIS) that is level or slightly lower than the posterior superior iliac spine (PSIS) (sagittal plane) and (2) a level position of both ASISs (frontal plane). Both ischial tuberosities should be equally weight-bearing. The lumbar spine has a natural lumbar lordosis accompanied by extension throughout other areas of the spine. The head and trunk are vertical, maintained in midline orientation over the pelvis with a “chin-in” position of the head. During active erect sitting, the line of gravity (LoG) passes close to the axes of rotation of the head and spine. During relaxed, erect sitting, the LoG is slightly anterior to these axes of rotation, whereas during slumped or slouched sitting, the LoG is well forward of these axes (Fig. 6.1).1


Normal sagittal plane postural ...

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