andyroberts1234
06-03-2011, 06:51 AM
Apologies for the cross posting (the below has already been posted on the ISS forum set up by Claudia Giacomozzi) I was not sure how many Biomech-L members were also on that forum.
We have been using RSScan for a year now in a clinical setting although are due to start some research soon. We have a 2m plate in the middle of a 10m runway. We have been using the automatic zoning to help guide clinical decisions for rehabilitation.
Over the last year we anecdotally noticed a trend towards higher pressures/summed forces for right feet. We have been in contact with RSScan support and their suggestions haven't really helped the problem. For ease of use, we have been using the automatic foot zoning although understanding that it probably wasn't perfect, we assumed that the algorithm to calculate each zone was the same for each foot- we have had some info from the company on how these are calculated. Last week we took a closer look at the manual zoning division screen and noticed a trend of there being more pixels on left feet that weren't assigned to any zone. This could potentially explain the differences that we were seeing between left and right as I believe (this is implied in the manual) only those pixels that are assigned to a zone are used when forces are combined by the software.
To make sure that this wasn't just due to problematic feet, we carried out a trial using 5 different people. Each person had ten trials. Five were walking in one direction, the remaining 5 in the other. Each direction had at least 2 Left and 2 Right feet as the first step on the plate. The number of unassigned pixels for each of the first 2 steps from each trial were then counted. The data was captured using the Windows Vista Footscan 7 2nd Gen (v7.97)
The results are in the table below. The mean number of unassigned pixels for left feet was 20.12, and 6.58 for right feet. The majority of unassigned pixels seem to be on the border between the metatarsal heads (M1-5) and the toes (T1-5).
I have contacted the company but am still awaiting a reply (after 2 weeks). I am sure some of the published research has also just used the automatic zoning so if this is an issue with their software then it could have further ramifications other than leading to erroneous clinical information (although they do state in the manual that zoning should be verified, systematic problems should not be expected with automatic zoning). Hopefully it is just a problem with our system.
Does anyone else have the same systematic issues with automatic zoning?
Kind regards
Andy
Trial 1st foot No. of unassigned pixels Left foot No. of unassigned pixels Right foot
f1 L 14 2
f2 L 20 0
f3 L 18 3
f4 R 17 1
f5 R 7 2
r1 L 23 0
r2 L 18 8
r3 R 35 6
r4 R 28 9
r5 R 24 15
f1 L 17 45
f2 L 22 0
f3 R 18 0
f4 R 0 0
f5 R 50 39
r1 R 38 39
r2 L 23 0
r3 L 13 0
r4 L 62 0
r5 R 12 0
f1 L 0 0
f2 L 35 1
f3 L 0 0
f4 R 10 1
f5 R 0 0
r1 R 0 0
r2 R 61 0
r3 R 17 0
r4 L 16 3
r5 L 1 0
f1 L 0 2
f2 R 33 27
f3 L 1 0
f4 L 53 1
f5 R 3 0
r1 L 0 0
r2 L 8 0
r3 R 49 0
r4 R 0 0
r5 L 13 0
f1 L 22 4
f2 L 25 10
f3 R 6 4
f4 L 27 6
f5 R 15 3
r1 L 25 16
r2 L 39 39
r3 L 26 5
r4 R 44 18
r5 R 18 20
We have been using RSScan for a year now in a clinical setting although are due to start some research soon. We have a 2m plate in the middle of a 10m runway. We have been using the automatic zoning to help guide clinical decisions for rehabilitation.
Over the last year we anecdotally noticed a trend towards higher pressures/summed forces for right feet. We have been in contact with RSScan support and their suggestions haven't really helped the problem. For ease of use, we have been using the automatic foot zoning although understanding that it probably wasn't perfect, we assumed that the algorithm to calculate each zone was the same for each foot- we have had some info from the company on how these are calculated. Last week we took a closer look at the manual zoning division screen and noticed a trend of there being more pixels on left feet that weren't assigned to any zone. This could potentially explain the differences that we were seeing between left and right as I believe (this is implied in the manual) only those pixels that are assigned to a zone are used when forces are combined by the software.
To make sure that this wasn't just due to problematic feet, we carried out a trial using 5 different people. Each person had ten trials. Five were walking in one direction, the remaining 5 in the other. Each direction had at least 2 Left and 2 Right feet as the first step on the plate. The number of unassigned pixels for each of the first 2 steps from each trial were then counted. The data was captured using the Windows Vista Footscan 7 2nd Gen (v7.97)
The results are in the table below. The mean number of unassigned pixels for left feet was 20.12, and 6.58 for right feet. The majority of unassigned pixels seem to be on the border between the metatarsal heads (M1-5) and the toes (T1-5).
I have contacted the company but am still awaiting a reply (after 2 weeks). I am sure some of the published research has also just used the automatic zoning so if this is an issue with their software then it could have further ramifications other than leading to erroneous clinical information (although they do state in the manual that zoning should be verified, systematic problems should not be expected with automatic zoning). Hopefully it is just a problem with our system.
Does anyone else have the same systematic issues with automatic zoning?
Kind regards
Andy
Trial 1st foot No. of unassigned pixels Left foot No. of unassigned pixels Right foot
f1 L 14 2
f2 L 20 0
f3 L 18 3
f4 R 17 1
f5 R 7 2
r1 L 23 0
r2 L 18 8
r3 R 35 6
r4 R 28 9
r5 R 24 15
f1 L 17 45
f2 L 22 0
f3 R 18 0
f4 R 0 0
f5 R 50 39
r1 R 38 39
r2 L 23 0
r3 L 13 0
r4 L 62 0
r5 R 12 0
f1 L 0 0
f2 L 35 1
f3 L 0 0
f4 R 10 1
f5 R 0 0
r1 R 0 0
r2 R 61 0
r3 R 17 0
r4 L 16 3
r5 L 1 0
f1 L 0 2
f2 R 33 27
f3 L 1 0
f4 L 53 1
f5 R 3 0
r1 L 0 0
r2 L 8 0
r3 R 49 0
r4 R 0 0
r5 L 13 0
f1 L 22 4
f2 L 25 10
f3 R 6 4
f4 L 27 6
f5 R 15 3
r1 L 25 16
r2 L 39 39
r3 L 26 5
r4 R 44 18
r5 R 18 20