The regular use and changing of socks to increase comfort or manage residual limb volume is common among persons with transtibial amputation, but many amputees do not use sock changes at an optimal level to reap health and comfort benefits, according to recently published data.
According to the study conducted by the University of Washington’s Department of Rehabilitative Medicine, researchers hoped “to quantify frequency and timing of sock changes and thicknesses of socks worn by persons with transtibial amputation. Of interest was how sock use differs between those who report use of socks for volume management … and those who report use of socks for comfort.”
Researchers created and distributed a custom “sock log” that allowed patients to report the socks they wore each day for a 2-week period, Brian J. Hafner, PhD, a co-author of the study, told O&P Business News. Hafner and colleagues were looking to identify the ways socks can be used to achieve and maintain good socket fit, such as sock changes throughout the day and the variation of sock thicknesses to prevent or manage socket issues. The study focused on patients who wore a prosthesis for a minimum of 4 hours daily.
“A good socket fit is important to ensure users’ residual limb and overall health. If the socket is too tight or too loose, users can experience pain, abrasions, wounds or other detrimental health issues,” Hafner said.
Patients were divided into two groups based on the information they provided to researchers: those who use socks to manage daily residual limb volume — and thus change socks regularly — and those who use socks primarily for socket comfort, and therefore do not typically change socks. The patients wore a prosthesis for an average of 15 hours per day. Of the 23 patients included in the study, 12 patients added socks throughout the day, 7 patients did not change socks and 4 patients removed their socks throughout the day.
The results showed a negligible difference between the two groups in terms of the frequency of sock changes.
“On average, our subjects started the day with about 5-ply socks and ended the day around 6-ply. The results also showed that, on average, people in the study changed socks less than once a day,” Hafner said. “We were surprised that users who initially self-reported as people who regularly changed socks to manage their socket fit didn’t change socks any more than those who just used socks for comfort. This tells us that changing socks may not be a strategy that is applied by patients as often as we think.”
Additionally, the authors stated, “These data suggest that socket fit may be suboptimal, and improved methods of volume management may be required to achieve an optimal fit.”
Brief period of action
Hafner said the discrepancy between the subjects’ initial reports of their own sock use and the sock logs could suggest that a brief period of action, such as an occasional sock change, is more easily remembered and affects the patients’ perception of frequency.
“For example, a user who changes socks once every few days may consider themselves someone who regularly uses socks to manage volume. However, their typical day-to-day behavior may be more representative of someone who does not add or remove socks,” he said.
The study also noted that if patients have an inaccurate perception of their own sock changing habits, the habits likely are being reported to physicians inaccurately.
“I believe this potential for misreporting clinical information speaks to a need to better understand practitioner instructions, patient behaviors and patient outcomes,” Hafner said.
The authors noted in the study that sock logs have practical use for diagnosis and treatment of socket fit issues.
“I believe a sock log could be useful for patients and practitioners who are trying to diagnose socket fit problems,” Hafner said. “For example, if a patient regularly experiences edema or skin breakdown, a practitioner could provide them with a sock log to assess their current volume management strategies. Then the patient and practitioner could work together to come up with a revised solution to address the volume management issues.”
The study offers a few recommendations to improve sock logs in the future. Modifications could include spaces on the form to allow room for patients to comment on their reasons for changing socks and the addition of complimentary, standardized measures of residual limb health. The authors also note future studies could assess different patient populations, post-amputation periods, climates or health care systems — any of which could provide different results.
Hafner said a number of important areas related to measuring socket comfort have yet to be well explored, including real-time measurement of socket fit and communication with patients about the optimal timing of sock changes. Hafner also would like to see a future study focus on the difference between practitioners’ instructions regarding sock change and patients’ behavior.
“If we find that there is good agreement between instructions and use, then tools like sock logs could be useful for troubleshoot problems,” he said. “If users do not well adhere to instructions, then there may be good opportunities to improve patient education materials or develop methods to help them better comply with practitioner instructions.” — by Amanda Alexander
D’Silva, Krittika. Self-reported prosthetic sock use among persons with transtibial amputation. Prosthetics and Orthotics International. 2014; doi:10.1177/0309364613499064.
Disclosure: Hafner has no relevant financial disclosures.