Power Tilt, Recline or Both
The evaluation of a client for a tilt or recline system requires
looking at all aspects of medical and environmental needs.
By David Kreutz, PT
he ability to use tilt, recline or sideration of the relative importance of
the user and seating system when com-
both can address a variety of user the following: paring different manufacturers.
needs. For people who are physi- • Medical issues. Tilt systems have also been found to
cally unable to alter their sitting pres- • Medical complications. be effective in reducing sitting pressures,
sures, changing positions for pressure • Desired functional outcomes. but to a slightly lesser extent. Research has
distribution is one of the most effective • Environmental considerations. shown that a minimum of 45 degrees is
methods for prevention of skin sores. Establishing a list for each of the four required for adequate pressure distribution.
Independent position items will help the team and the client set While in tilt, a person actually shifts
changes are also neces- and prioritize goals. It is then important weight from his or her sitting interface
sary for people who to test these goals through simulation of onto the back. Although this is an ade-
The procedure for experience postural the power seating system and evaluate quate pressure shift for most people,
hypotension and dysre- the effectiveness of the functional activi- some may experience only a small reduc-
setting a fixed flexia. ties while using a power seating system. tion in sitting pressure.
Another benefit is that Once this is completed, the team can Interface pressure-mapping systems
degree of tilt and postural alignment can be begin to compare specific technology can provide objective measurement of
its impact on the improved by changing considerations to determine the most interface pressures and can be used to
the orientation of the appropriate seating system. determine the effectiveness of power tilt
total degrees of body and seating system systems in distributing pressure. Concern
relative to the pull of Review of Medical Issues about the degree of pressure reduction
travel varies gravity. This so-called II4 Pressure Distribution with positional changes may become
considerably from gravity-assisted position- One of the major reasons for using a more important if the user requires a
ing can address some of power seating system is for pressure dis- fixed degree of tilt (about 10 degrees) for
one manufacturer the postural support tribution. For clients who lack sensation balance. The seating team needs to evalu-
needs of the user and at and/or who are unable to change posi- ate the impact the total degree of tilt has
to the next. the same time allow for tions, pressure distribution is a key com- on pressure distribution. However, the
improved function. ponent in preventing skin breakdown. procedure for setting a fixed degree of tilt
Most people who use power seating Power recline systems were one of and its impact on the total degrees of
systems are either dependent or have the first mechanical methods that allowed travel varies considerably from one man-
severely impaired sitting balance. Power someone to redistribute pressure for pres- ufacturer to the next. This should be care-
seating systems used with other postural sure sore prevention. By reclining, the fully explained to the client and evaluated
supports can dramatically improve sitting person distributes his or her sitting pres- with simulation.
balance. Increased comfort can lead to sure over a larger area and allows blood In cases in which powered tilt has
increased sitting tolerance, which may not to return to the ischemic areas. been selected for meeting the goals of
be possible without a power seating system. Today, power reclining systems are postural stability or inhibiting spasticity,
Determining the optimal seating sys- still one of the most effective means of but is inadequate for pressure distribu-
tem/user match, however, depends on distributing pressure, but one may find tion, it may be necessary to combine tilt
much more than just these medical considerable differences in the degree of and recline. Using a combination tilt and
issues. The best match evolves from con- recline and the amount of shear between recline requires sequencing the operation
T E A M R E H A B R E P O R T 29
Table 1. Medical Considerations When Evaluating Tilt and Recline Power Seating
Consideration Tilt Recline Comments
Spasticity + - Tilt systems do not elicit spasticity to the extent that a power recline
system will, because they maintain static joint angle and muscle
lengths during positional changes.
** + Water runs downhill. Tilt systems may interfere with this if catheter
management tubing is not carefully routed to prevent the flow of urine from revers-
ing. Access for intermittent catheterization may also be a problem in
a power tilt system and should be assessed.
Hip flexion + - Tilt systems with adjustable seat and back angles that can be adjusted
contracture to less than 90 degrees will accommodate this type of contracture.
greater than 9V
Hip extension + + Tilt systems must have an adjustable seat-to-back angle to accommo-
contracture date such contractures. Recline systems should have adjustable limit
switches to prevent the seat-to-back angle from being closed beyond
the available hip range. Otherwise, the reclining back will push the
person off the seat.
Visual orientation + + Both systems provide a mechanism to compensate for a fotward head
posture and improve their visual orientation and comfort.
Switch access The ability of the user to access a switch for operation of the power
seating system should be tested throughout the available range. If the
method interferes with switch access or limits the range of operation,
it may be necessary to look at different sites for switch placement or a
different method of position change.
Need for custom- + - The use of an aggressively contoured back in combination with power
moldedseating recline systems presents a problem. The offset of the axis of rotation
of the seating system is not the same as the person’s, Therefore,
when the person reclines, the backrest shears or moves relative to the
person. This causes the back to no longer fit appropriately.
Transfers The ease or difficulty of the transfer depends on the type of transfer
more than the type of seating system. Numerous transfer methods
and wheelchair options are available, which should restrict the use of
+ recommended - not recommended ** with careful consideration
of the system to ensure postural stability. ty to improve his or her vertical sitting tol- Conversely, a power reclining system
The person should be instructed to tilt erance. By tilting or reclining, the person opens the seat-to-back angle, taking away
to the maximum degree first to provide can get the center of gravity of the upper the posterior pelvic support. This results in
postural stability. Subsequent activation of torso and head behind a more proximal a loss of pelvic and spinal support and
the power recliner then improves the stabilized body part, thereby gaining bal- may contribute to a more kyphotic sitting
amount of pressure distribution without ance and stability. The degree of recline posture.
loss of posture. Care must be taken to close and tilt necessary to achieve this will vary
the recline angle and then use the tilt sys- from person to person. l OrthostaticHypotension
tem to return to a vertical position without Tilt systems actually do a better job of This is a condition that results in a signifi-
losing postural stability. this by changing the orientation of the entire cant drop in blood pressure when the per-
seating system while maintaining the con- son is brought into a vertical sitting posi-
l Gravity-AssistedPositioning tour and angle of the seat and back. This tion. This condition is common among
Another medical issue for using a pow- means that the person should have nearly people with low blood pressure or people
ered seating system is to use gravity to the same posture in a vertical position as he who have been on extended bed rest. If
assist in positioning and function. A per- or she does when fully tilted. This posture is not monitored or addressed with therapeu-
son who is dependent in sitting balance less likely to change as the person performs tic interventions, the person could be
must rely on the seating system and gravi- this activity over time. Continued on page 32
3 0 M A R C H 1 9 9 7
l Weight limit of the system
tion to these issues, medical complications or
lWhat is the weight limit? Is this the weight
considerations must be taken into account when
of the user or the combined weight of the
determining to use a tilt, recline, or a combina-
seating system and user?
Continued from page 30 tion tilt-and-recline system (See Table 1).
H Stability of the system in a full tilted
brought to a vertical sitting position and lose Once the medical and functional considera-
consciousness. Both power tilt and power tions have been outlined and prioritized, it is
H Stability of the system in a full reclined
recline systems are effective in allowing the time to compare different manufacturers’ position
person to change position to compensate for power seating systems. The following is a list
this drop in blood pressure. Interventions such of some of the technology considerations and
What is the minimum and maximum seat
as abdominal binders and compression stock- related thought-provoking questions.
ings should also be considered to reduce the
What is the overall length and width?
hypotension. l Degrees of Tilt
l Ability to add additional postural
l Is this adequate for pressure distribution? supports
l Sitting Tolerance and Comfort Can a fixed degree of tilt be set into the
l Optional components (head supports,
Sitting tolerance may be compromised in a system for postural stability? If so, does this arm supports, leg supports)
person with poor endurance and/or dependent limit the total degree of tilt or have any
l Ability to add other power features such
sitting balance. From a functional standpoint, impact on the tilt mechanism?
as seat elevator, standing, power elevating
some people may be able to function for 8 to l Degrees of Recline
10 hours alone once given the ability to change What is the maximum degree? Can it be
l Ability to customize
positions for comfort and function, which limited?
H Growth capability in seat and back width
translates into increased independence. l Degrees of each when used in combina- as well as seat depth
Preference for tilt vs. recline as it pertains to tion of tilt and recline
What mechanisms are available for tie-
comfort depends entirely on the person sitting Does combining tilt and recline limit the
down in a van?
in the wheelchair. degree of recline?
l Warranty and cost
. Can the drive mechanism of the wheel-
Other Medical Considerations chair be locked out through limit switches? David Kreutz, PT, is a seating specialist at
The issues identified above are the key medical At what degree of tilt and recline? How is Shepherd Center, 2020 Peachtree Road N.W.,
reasons for justifying this equipment. In addi- this adjusted? Atlanta, GA 30309; 404/352-2020.