# Hand Neuropathies and Musculoskeletal Disorders: Complementary Diagnosis Using IR Thermography
## 3 Results and Discussion  
All thermal images of the hands, acquired for both the injury group and the control group, from dorsal and palmar perspectives, underwent processing to standardise the temperature scale and segmentation to eliminate the background. The selection of ROIs was based on the sensory territories controlled by the nerves on each surface of the hand, specifically the median, ulnar, and radial branches. The regions most commonly affected in orthopaedic lesions, which include the finger joints (metacarpophalangeal joint, proximal  
Figure 4: Thermal image with the regions of interest of the dorsal area (**a**) and palmar area (**b**). A—Arm; TM—Thumb metacarpophalangeal; TP—Thumb proximal; FM—Forefinger metacarpophalangeal; FP—Forefinger proximal; FD—Forefinger distal; MM—Middle metacarpophalangeal; MP—Middle proximal; MD—Middle distal; RM—Ring metacarpophalangeal; RP—Ring proximal; RD—Ring distal; LM—Little metacarpophalangeal; LP—Little proximal; LD—Little distal; RB—Radial branch; MB—Median branch; UB—Unar branch. Figure 3: Setup of thermal data acquisition in two hand regions: dorsal and palmar. interphalangeal joint, and distal interphalangeal joint), as well as the region constituted by the radius (named as arm ROI), which is the larger bone situated on the thumb side of the arm, were also considered. After extracting the mean temperature values from all the hands of the injury and control groups, for each ROI, the data were subsequently separated into two variables, each represented in a column, one for the control and the other for injured, to be further used in the SPSS analysis. To evaluate the data distribution, the descriptive statistics by group was obtained by running the Compare Means test. This allowed to create a comparative box plot illustrating the mean temperature values in degrees Celsius (\"C\"), for each hand perspective. The graph relative to the dorsal view is presented in Figure 5. The control group exhibits a distribution with a negative skew, indicating that the majority of data points are concentrated in the lower region of the distribution, corresponding to lower temperatures, as would be expected in healthy people. The injured group presents a normal distribution, with the data evenly distributed around the mean. None of the distributions display outliers. Considering the compact size of the boxes, it suggests that there is a high level of agreement between all the participants in both the control and the injured groups. The first group displays a maximum mean temperature of 34 \"C\", while the second group registers a notably higher temperature of 35.8 \"C\", reflecting a difference of 1.8 \"C\" between the two. The control group demonstrates a significantly lower minimum mean temperature (27 \"C\") in comparison to the injured group (29 \"C\"), signifying a substantial difference of 2 \"C\". The mean temperature in \"C\" for the control group is 31.39, with a corresponding standard deviation of 1.65, which indicates a degree of consistency in the recorded temperatures. In the injured group, these values are 32.41 \"C\" and 1.35 \"C\", respectively, which implies that the temperatures tend to be clustered around the mean temperature. This highlights a thermal difference of 1.02 \"C\", indicating the mean temperature of the control group is significantly higher than that of the injured group. Therefore, the maximum and mean values within the dataset are higher in the injured group, whereas the minimum is lower in the control. This conclusion is validated by the level of significance between the two groups \"\"\(p<0.01\), which indicates that the mean dorsum temperature were significantly different between the two groups. The box plot correspondent to the palmar perspective is depicted in Figure 6. Similarly to the previous plots, the control group shows a negatively skewed distribution, although more accentuated, with few data points on the upper side and more concentrated in the area of lower temperatures.