Kosuke Morinaga*, Shigekazu Ishihara, Shun Tarumoto, Masako Nakahara, Toshio Tsuji
In recent years, many compression socks have been marketed with the purpose of improving swelling and leg shaping. They either apply uniform pressure to the entire lower leg or apply pressure in stages starting from the foot. Both types attempt to apply pressure to the entire circumference of the leg at the same pressure. These are strongly woven to apply pressure, making them difficult to wear and often causing a feeling of tightness. Therefore, new partly- compression socks were devised to apply pressure selectively to the upper part of the gastrocnemius muscle (the back of the lower leg) rather than uniformly around the entire leg.
In this research, three measurement experiments were conducted using fully-compression socks, partly-compression socks, and normal socks: actual pressure measurement, measurement of circumference and volume change in the morning and afternoon, and subjective Kansei evaluation were applied in this research.
Experiment 1: The pressure exerted by a sock was measured using an air pressure sensor with our originally developed pressure measurement device. A mannequin was fitted with socks, and the actual pressure was measured.
The normal socks had lower pressure below the knee, and the partial and full compression socks had higher pressure below the knee. On the anterior surface of the upper gastrocnemius (58% of the area from the external capsule to the lower patella), the partial and full compression socks had the same pressure, with the normal sock having the lowest pressure. On the posterior surface, the partly-compression sock had the highest pressure. Partly-compression socks have the pressure at the back about 1.4 times higher than that at the front. Compared to the full-compression socks, the ankle pressure of the partial-compression socks was smaller.
Experiment 2: With three types of socks, volume and circumference changes of the lower leg were measured in the morning (8:00-9:00) and in the evening (17:00-18:00) during the working day. Volume difference in the daytime has significantly differed between the socks. There was a significant difference between normal and partly-compression.
The change amount in circumference was measured at 3 locations on the lower leg; maximum circumference of the lower leg measured in the sagittal plane, circumference at the maximum diameter of the lower leg in the sagittal plane (73% of the distance from the lateral malleolus to the lower patella), the height at which the change in swelling was greatest (58% level). At all locations, circumference difference amounts along the time are significantly different between the three socks. Partly-compression has the smallest difference, then full-compression and normal socks. There is a significant difference between normal and partial compression at all height levels.
Experiment 3: Kansei Evaluation on socks. Both Partly-compression socks and Fully-compression socks in the morning are associated with “squeezing”, “slenderize leg”, “feel get into shape”, “fits”, “feeling good for blood circulation,” and “lighter leg”. Full-compression socks are not varied for morning to evening duration.It seems to keep participants aware of compression.
Partly-compression socks in the evening moved close to not “cold” and “warm”. Partly-compression socks tend to make participants unaware of compression and body-worn feeling during the day time.
Conclusion: In conclusion, partly-compression socks have the best performance on both volume and circumference change amount and are also good at Kansei evaluation on comfort.