The BK Toddler: Suspension Techniques

Janet G. Marshall, CPO; Tampa Shriners Hospital for Children

Our facility encounters a suspension Strutter Canes problem whenever we are fitting a Below Knee (BK) prosthesis on a toddler. To coincide with normal milestones, the fitting is complete around the first birthday or when the child begins to pull to stand. The challenge is to secure the prosthesis during all of the transitions of floor mobility, cruising, and walking.

One suspension option is the supracondylar cuff, also called suprapatellar strap. Through suspension above the patella, the knee is allowed to bend for crawling and the circumferential strap can be infinitely adjusted with Velcro. This must be custom made for the toddler and works well using flexible nylon web strap, elastic, and a "D" ring. (Figure 1 ). In the case of a challenging fit of a shorter residual limb, the supracondlyar may not work to hold the prosthesis in place. A second option is a custom neoprene knee sleeve with the popliteal region cut away to, allow free knee flexion.

Figure 1

Occasionally, neither of these methods has been successful with "our little Houdini's", which has led to the design of the "BK Holster" (Figure 2 , Figure 3 ).

Figure 2

Figure 3


The following measurements are needed:

  • Waist circumference with overlap allowance,
  • Proximal three inch BK prosthesis circumferences,
  • Distance from the waist (lateral) to the bottom of these circumferences.

The basic design resembles a TES AK suspension belt, with Velcro closure, that extends to below the knee and is typically made out of neoprene. If heat intolerance is an issue, a stretch mesh material can be sub-bead of silicone applied to prevent slipstituted (Figure 4 ).

Figure 4

The sleeve section should ping. The BK holster can be made unilatbe tapered to maintain suspension of the BK (Continued on page 32) and may need to be rubber backed or have a bead of silicone applied to prevent slipping. The BK holster can be made unilateral or bilateral and has been the most successful solution to the toddler who defies more conventional suspension techniques. A pattern that can be cut from one piece of material is shown below (Figure 5 , Figure 6 ).

Figure 5

Figure 6

The feedback received from the therapists and families has been positive for decreasing the need for reapplying the prosthesis through out the day. Another benefit is the proprioceptive input and stabilization provided to the pelvis during initial gait training. The end result facilitates acceptance of the first prosthesis and progression to develop the necessary skills for upright mobility. Eventually, the more traditional method of suspension can be used as the child becomes more proficient and incorporates the prosthesis into his or her daily activities.