LA AUTORIDAD DE LOS POETAS

The current study has some limitations such as small sample size and the subject used having a knee varus deformity without complaining from pain or knee OA or any previous injury. As a result, one of the future plans is to increase the sample size to include medial compartment knee OA participants in a future investigation. Another limitation of this study is that it evaluated the immediate effects of KAFO and knee braces on the primary outcome measures. A longitudinal study could be helpful to examine the long term effects of using KAFO on the knee load and OA progression. Furthermore, because of that reason it is difficult to know if these orthoses would reduce pain and improve activity levels. Also, using a simple ankle joint limits ankle joint movement and a free mechanical ankle joint will be used in future even though it will increase KAFO weight and cost.

Besides that, it is important to examine if using a custom KAFO is acceptable to be used for long periods or not and the associated side effects. Nevertheless, the design of KAFO used in this study is considered as being lightweight compared to other designs, and the absence of straps around knee joint gives it a more comfortable feeling when flexing the knee particularly when using stairs and it is able to provide an intimate fit as it was custom made. Nevertheless, its cost will be more than an OTS knee valgus brace but still it does not cost as much as some types of knee valgus braces which contain air champers. The author's experience found that this design of KAFO is already used and recommended for individuals with very severe knee OA in some countries who wish to avoid undergoing total knee replacement surgery and have not previously found any benefit of using knee valgus braces; however, the long term effect of using a long brace needs to be investigated. In contrast, the limitations of using knee valgus braces have already been reported, such as poor fit (especially the OTS knee valgus brace), skin irritation, discomfort when flexing the knee due to knee strap impingement (Stamenović et al., 2008),

discontinuation of use (Squyer et al., 2013). In addition, some designs are bulky, heavy, and are not acceptable for long term use, and some individuals have complained from swelling and thrombosis after 6 months of use (Giori, 2004).

With regards to the biomechanical testing, markers artifacts due to skin movements could be one of the limitations during walking and stair climbing, but because of the use of dynamic tracking markers (clusters) and a good shoe fit with a tight lace, the artifacts would have been reduced. For static alignment capturing, two static alignments were captured before the participant started walking and the shoe size was the only variable which had changed. The rest of the markers were still in the correct position during the two static alignments and their location was marked and checked. In addition, off-the-shelf knee valgus braces may not offer an intimate fit for some individuals as they are not custom made, but the one which was used in this study was an adequate fit for the participant.

The ten minute washout period between treatments may not have been long enough but it was thought to be acceptable because using braces inflict immediate biomechanical changes in knee angles and load, and it is suggested that the knee biomechanics returns to the original position and alignment immediately once the braces are removed (Draganich et al., (2006). Finally, the staircase which was used in this study contained only three steps; therefore, the contra lateral side was not evaluated. Having a staircase with more than three steps could be helpful to evaluate the both sides and give information about the effects of a KAFO on both the affected and non-affected side.

5.2. Future work

This pilot study evaluated a new modified type of KAFO which could be a possible conservative treatment for medial knee OA in the future. Therefore, the next phase would be to evaluate the device in a sample of medial knee OA subjects and appraising if this design incorporating a free ankle joint could help to reduce EKAM, KAAI, and knee varus angle during walking and negotiating stairs. Also, a free mechanical ankle joint could be added to the KAFO design

instead of a plastic one to add more ankle motion freedom and add more plantarflexion freedom during stair climbing. Further assessments of pain and activity levels, muscles activity, energy consumption, and quality of life enhancement could be examined in the future study after using the device for an extended period such as for between six and twelve months.

5.4. Conclusion

After taking into account the study limitations, this study is the first study to evaluate the effect of a modified KAFO for knee varus individuals during walking and stair climbing. The data from this pilot study supports use of a modified KAFO to reduce EKAM, KAAI, and knee varus angle during walking and stair climbing and also giving improved hip and knee range of motion. However, the limitation of the ankle range of motion is something which needs addressing before embarking on a follow-up study. Therefore, the data supports that wearing a KAFO can significantly reduce EKAM and knee varus deformity and it could be one of the future interventions for individuals with medial compartment knee OA who have a varus aligned knee joint especially if current treatment (knee valgus braces for example) are not restrictive or corrective enough.