Veterans Affairs

Vertical lift walker for sit to stand transition

Improved assistive lift walker helps restore independent sit-to-stand and walking functions for patients with limited leg strength and motor control

Medical & Biotechnology

(a) Walker is locked in the seated position. (b) Upon pressing the release button, the gas springs exert 890 N (200 lbs) of force through the shoulders of the user to lift him from the chair. (c) Walker locked in the fully extended position, capable of supporting loads in excess of 300 pounds.

Rising from a sitting position is a complex muscle maneuver. Most individuals take it for granted and it is the key to independence. But for those with lower extremity weakness, this movement can be impossible. While walkers address a portion of this problem, previous attempts to develop devices which further assist in elevating a person to the walking position have been problematic. Battery driven motors and linear actuators have been used in such attempts which have added weight and bulk thus hindering adoption. Other proposed solutions do not properly mimic the musculoskeletal action of a person and end up pitching the individual off balance.

Scientists at the VA have envisioned and prototyped a lift walker addressing the above issues. The new apparatus is extremely versatile and can assist a person to stand or be transferred to a sitting position in a chair, bed, or bathroom. It is built of a lightweight, low-cost frame that lends itself to rapid and easy assembly and disassembly. Despite this lightweight, portable structure, the lift walker can assist a weak or paralyzed individual to stand for periods of time, even for heavier individuals who may require support at all times, and can do so without the need for gripping of handles, or the use of user retention harnesses.

The lift walker provides essentially constant force output through the entire range of a vertical platform motion, without the disadvantages of rotary motion towards the user, and without the use of powered systems involving motors or batteries. This is done with the use of coordinated gas springs that are implemented in a novel way so as to create an electrical power-free lift assist walker with evenly balanced vertical lift. Such operation is especially advantageous to the spinal cord injury or geriatric populations which lack the hand function needed for gripping handles in order to maintain coupling with a walker platform.

Unlike known systems, the lift force, as well as the size and range of motion of the lift walker, can be customized on an individual basis, depending on the specific weight or size of a user. The device includes anti-tip features which help avoid frontward stoppage that can tip the unit and possibly the user over the front end.

Do you have questions or need more information on a specific technology? Let's talk.

Contact Us