Postural Control In Sitting

FUNCTIONAL ANATOMY OF THE TRUNK:

• MUSCLES OF THE ABDOMINAL WALL & LATERAL TRUNK

• Purpose:

  • 1. Support Vital Organs

  • 2. Respiratory assist

  • 3. Trunk control

FUNCTIONAL ANATOMY OF THE TRUNK

• Posterior Trunk Muscles

• Purpose:

  • 1. Balance of the vertebral column

  • 2. Trunk control (extension, lateral flexion, rotation)

  • 3. Approximates head to sacrum and pulls pelvis to anterior tilt

  • 4. Accentuates lumbar lordosis

MOTOR CONTROL CONSIDERATION

• Types of muscle actions

  • ***concentric contraction

  • ***isometric contraction

  • ***eccentric contraction

1. Movements in directions opposite the pull of gravity (concentric contraction)

2. Prevention of movement that would take place as a result of the pull of gravity (isometric contraction)

3. Controlling the speed of movement taking place in the direction of the pull of gravity (eccentric contraction)

MOTOR CONTROL CONSIDERATION

• Motor Control:

Motor Control: how our neuromuscular system functions to activate and coordinate the muscles to perform a skill

1. Reciprocal innervation

2. Postural malalignment & normal muscle length

3. Dissociation

4. Voluntary vs. automatic

GENERAL CONSIDERATIONS FOR EVALUATION

1. Ask client to wear a gown

2. Subtle postural shifts will completely change muscle activity

   1. everyone tends to sit in a posterior pelvic tilt

3. Evaluate at a variety of functional postures

   1. Supine

      1. eliminates gravity (e.g., are muscles misaligned, even when the person doesn’t have to work against gravity?; problematic, possibly tightness somewhere)

   2. Sitting

      1. have gravity now; see what kind of control they have against it, and if that impacts their asymmetries

   3. Internal Perturbations

      1. Caused when a person fails to control the base of support during voluntary movement (e.g., sitting and dressing)

      2. nothing is externally forcing them; they just don’t have the internal strength to stay upright —> e.g., fall

4. External Perturbations

   1. When the surface moves (e.g., sitting on a therapy ball) or something outside makes us move (e.g., being pushed by OT to test sitting balance, windy day)

EVALUATION PROCEDURES

• observations

  • static

  • dynamic (task)

• Observed postures may be the result of a variety of problems:

  • Posterior pelvic tilt

  • Lateral flexion

  • Rotation

• Control of selective movement patterns

  • Trunk flexors

  • Trunk extensors

  • Lateral flexion

  • Rotation

• Assistance level for (1) static sitting balance/(2) dynamic sitting balance

  • Independent static/dynamic sitting balance: requires no physical or verbal cues

  • Supervision: requires supervision (verbal cues) with no physical assist

  • Contact guard (CG): touching assist

  • Minimal (min) assist: 25% assist

  • Moderate (mod) assist: 50% assist

  • Maximal (max) assist: 75% assist

  • Total assist: 100% assist

EVALUATION PROCEDURES

• Control of selective movement patterns

  • Trunk flexors

  • Trunk extensors

EVALUATION PROCEDURES

• Control of selective movement patterns

  • Lateral flexion

1. leading with the shoulder to the right

• weight-shift to the right

• eccentric contraction of the left (so you don’t fall over)

• left side is elongating

• right side is shortening

2. going to sit back up

• concentric activation of the left (to actively come back up)

3. hip hike of the right

• concentric activation of the right side to lift it up

• weight shift to the left

• right side is shortening

• left side is lengthening

EVALUATION PROCEDURES

• Control of selective movement patterns

  • Rotation

rotating to left

• left side: internal obliques

• right side: external obliques

rotating to right

• left side: external obliques

• right side: internal obliques

EVALUATION PROCEDURES

• static sitting balance

patient is not doing anything besides sitting (try to have their feet on the ground if they are lower level/need more help)

• Assistance level for (1) static sitting balance/(2) dynamic sitting balance

  • Independent static/dynamic sitting balance: requires no physical or verbal cues

  • Supervision: requires supervision (verbal cues) with no physical assist

  • Contact guard (CG): touching assist

  • Minimal (min) assist: 25% assist

  • Moderate (mod) assist: 50% assist

  • Maximal (max) assist: 75% assist

  • Total assist: 100% assist

EVALUATION PROCEDURES

• dynamic sitting balance

patient is doing something while sitting (e.g., dressing)

• Assistance level for (1) static sitting balance/(2) dynamic sitting balance

  • Independent static/dynamic sitting balance: requires no physical or verbal cues

  • Supervision: requires supervision (verbal cues) with no physical assist

  • Contact guard (CG): touching assist

  • Minimal (min) assist: 25% assist

  • Moderate (mod) assist: 50% assist

  • Maximal (max) assist: 75% assist

  • Total assist: 100% assist

STANDARDIZED EVALUATIONS

• Trunk Control Test

can be used to assess the motor impairment in a patient who has had a stroke; it correlates with eventual walking ability

• testing done by patient lying in bed:

1. roll to weak side

2. roll to strong side

3. balance in sitting position on the edge of the bed with the feet off the ground for at least 30 seconds

4. sit up from lying down

STANDARDIZED EVALUATIONS

• Trunk Impairment Scale (TIS)

scores

• static sitting balance

• dynamic sitting balance

• coordination

TRUNK CONTROL AND ADL

• Clear relationship between loss of trunk control and loss of functional independence

• Prior evaluations focused on select movements of the trunk; however, the impact of impaired trunk control on functional tasks is more relevant to OT

• Therefore, the evaluation of trunk control can take place during skilled observations

• While there are infinite variations of observed movement patterns during task performance, the focus of evaluation and treatment should be observing, evaluating and treating patients with a variety of tasks and environments

• e.g., Lower extremity dressing

  1. Trunk flexion to reach down toward feet

  2. Trunk flexion and rotation to reach to one side of body (ex., Right)

  3. Trunk extension to realign to sitting position

  4. Lateral flexion required when using a cross-leg method (ex,. Right leg over left leg)