With our recent pieces on the Step-On 100 medial and lateral hinge AFO options, you are probably wondering why the dual hinge? We thought that we would share some clinical scenarios which have been proven to be successful with the dual hinge, and demonstrate its adaptability. We hope it will help you in your decision making when prescribing a device from the Step-On family, and help you problem-solve a future similar scenario with good results.
Firstly, due to the dual hinge, we gain a slightly higher amount of power to dorsiflex the foot for swing, without any potential for transverse plane rotation. Therefore, we can better control the advance in tibial inclination in stance/resist reclination.
The extra control is especially useful for clients who have increased BMI, and/or exceptionally large and heavy feet with complete loss of power in the anterior compartment muscles; if you are struggling with swing clearance adequately with the Step-On 100, then 200 should be the solution. The extra control was especially useful in a client with a posterior distal thigh trauma with excision of large tumour, resulting in decreased hamstring power. The client had a mildly hyperextending knee and stress to the ACL with symptomatic pain. Due to trauma and CRPS a knee brace could not be used/tolerated, but the dual hinge resisted hyperextension adequately to incline the tibia forward, to prevent the problematic strain on the ACL. By dialling in on the hinge, the exact amount of control over the hyperextension moment at loading response was achieved, whilst still allowing the client a functional ankle range. Similarly, any client displaying dorsiflexor weakness and a mildly hyper extending knee, who demonstrates the ability to walk on a flexed knee, would do well with the 200 to help resist the mild hyperextension.
Having the dual hinge creates a much increased M-L stability, and clients who require increased M-L control are well-served. For those who have unstable ankles, or who excessively invert/evert, whereby the single strut would be struggling to hold the ankle position, we suggest the 200. Additional to the dual struts, its design offers an added feature of slotting the ankle straps in the tibial case for better purchase for valgus or varus control.
Another useful feature we have found is the four sizes: when choosing between the ‘Small’ to ‘Extra Large’, although the footplate length increases slightly, the most helpful and noticeable change is the bi-malleolar width, so we find although the shoe sizing is a useful indicator, we would like you to consider the bi-malleolar width first to ensure optimum fit at the ankle.
The Step-On 200, being part of the Step-On family, shares all the same high quality materials, heat mould ability, and ankle ROM and adjustment of the 100 options.