Comfort evaluation techniques are commonplace in medicine. However, measures of lower-limb comfort are infrequently used in the sporting environment. The purpose of this study was to develop an instrument for measuring lower-limb comfort, which will extend previous work in the field of injury awareness.
A lower-limb comfort index (LLCI) was developed for use in the environment of elite sport. Forty professional footballers participated in development of the index. The study had three components. A critical appraisal of the literature established the need for an LLCI. The second phase involved 20 professional footballers establishing and testing the components of the comfort index as an instrument for measuring comfort.
Nonparametric statistics (the McNemar test) in phase 2 indicated that the LLCI demonstrated good responsiveness to suitability (P = .019) and ease of use (P < .01). After a high level of agreement for responses, the third stage required 20 players to pilot test the reliability of the LLCI in a controlled environment. Repeated measures of difference between two periods for sum comfort (intraclass correlation coefficient = 0.99) and individual anatomical segments (κ = 0.72–1) provided confidence that the comfort index was reliable.
The LLCI showed good trait construct to provide confidence to conduct a future study to investigate interrater consistency in a wider cohort of professional footballers under different conditions, such as match-day and training-week environments. (J Am Podiatr Med Assoc 101(5): 371–384, 2011)
Foot pain and lower-limb neuroischemia in diabetes mellitus is common and can be debilitating and difficult to treat. We report a comparison of orthotic materials to manage foot pain in a 59-year-old man with type 1 diabetes mellitus, peripheral neuropathy, peripheral arterial disease, and a history of foot ulceration. We investigated a range of in-shoe foot orthoses for comfort and plantar pressure reduction in a cross-sectional study. The most comfortable and most effective pressure-reducing orthoses were subsequently evaluated for pain relief in a single system alternating-treatment design. After 9 weeks, foot pain was completely resolved with customized multidensity foot orthoses. The outcome of this case study suggests that customized multidensity foot orthoses may be a useful intervention to reduce foot pain and maintain function in the neuroischemic diabetic foot. (J Am Podiatr Med Assoc 98(2): 143–148, 2008)
Background: Subjective comfort of footwear is important for shoe and orthosis design. This study compared shoe preferences between walking and running, using subjective comfort as an outcome tool.
Methods: Forty-one participants walked and ran 20 times each along a runway in three types of footwear (cushioning, lightweight, and stability) and chose the model that they preferred most for walking and running separately based on subjective comfort.
Results: More participants preferred the cushioning model (walking, 34%; running, 41%) or the lightweight model (walking, 44%; running, 41%) over the stability model (walking, 22%; running, 17%). χ2 tests revealed no differences between walking and running, runners and nonrunners, and lighter and heavier individuals. Women were more likely (odds ratio = 4.09) to prefer the lightweight model, whereas men preferred the cushioning (odds ratio = 2.05) and stability (odds ratio = 3.19) models. Most participants (71%) chose the same model for both activities.
Conclusions: Shoe preference varies among individuals and is influenced by sex. Most people feel comfortable walking and running in the same shoe model. (J Am Podiatr Med Assoc 100(6): 456–462, 2010)
The effects of shoes and foot type on balance are unclear. We aimed to investigate the differences between static and dynamic balance among three foot types and the changes in postural balance while wearing typical athletic shoes.
Based on the Foot Posture Index, the feet of 39 participants were classified as pronated, neutral, or supinated by a physiatrist. Static and dynamic balance function were assessed by center of gravity (COG) sway velocity with eyes open and eyes closed and a modified Star Excursion Balance Test in a random order with participants either barefoot or wearing shoes.
The COG sway velocity was significantly higher in the supinated foot group than in the neutral foot group (barefoot: eyes open, P = .004, eyes closed, P = .001). Normalized composite reach distance (NCRD) was significantly lower in the pronated and supinated foot groups (barefoot: P = .039, P = .008; shoes: P = .018, P = .018). In all three foot type groups, COG sway velocity was significantly decreased (P < .05) and NCRD was significantly increased (P < .05) while wearing typical athletic shoes.
The medial longitudinal arch of the foot affects postural balance. Typical athletic shoes improve postural balance regardless of foot type. However, the pronated and supinated foot groups still had lower dynamic postural balance compared with the neutral foot group, even when wearing athletic shoes. People with pronated and supinated feet may need additional interventions, such as foot orthoses or balance training.
Background: A scientific study was conducted to evaluate the effects of non–custom-molded (over-the-counter) foot orthoses.
Methods: Several parameters were examined, including foot, knee, hip, and back pain; balance; and reduction in flexible deformities, such as hammer toes and hallux valgus. Wherever possible, objective measurements were used, including measurements of shifts in center of pressure to assess balance and changes in bone position examined on radiographs. Forty-one individuals were analyzed using one of two types of prefabricated, noncustom insoles. Insoles were fit by an assistant trained to follow the fitting recommendations of the manufacturer under the direct supervision of a podiatric physician.
Results: Use of these arch supports resulted in a significant reduction in some types of foot pain associated with hallux valgus (P = .04) and pain in the arch area (P = .004), knee (P = .002), and back (P = .007) by week 4. We also measured changes in foot position documented by radiography, although some changes may be attributed to parallax associated with measurement techniques. Improvement in balance was not observed to be significant when the orthoses were worn.
Conclusions: Using both subjective and objective measures, we found that these over-the-counter foot orthoses were effective in bringing about changes in foot shape and concomitant relief of certain specific painful conditions. This study indicates that there is a scientific basis for attempting to relieve pain with orthoses. (J Am Podiatr Med Assoc 99(3): 206–215, 2009)
Playing soccer on artificial turf can provoke pain in young players. Using shock-absorbing insoles (SAIs) can result in decreased pain perception. We sought to investigate the pain and comfort intensity experienced during the switch from natural grass to third-generation artificial turf and with the use of SAIs on artificial turf during training in young soccer players.
In a prospective randomized controlled study, 75 players were included from the youth teams of U15, U17, and U19. Pain intensity and comfort were assessed after training on only grass turf for 3 months. Randomization stratified by team level and age was performed; the intervention group received SAIs, and the control group used their own insoles. Assessments were repeated after 3 weeks on artificial turf (baseline) and 3 more weeks (follow-up) on artificial turf with SAIs/usual insoles.
Pain intensity increased and comfort decreased significantly after 3 weeks of training on artificial grass compared with natural grass (P < .05). The addition of SAIs resulted in significantly reduced pain intensity compared with the usual insoles (P < .05).
The switch to artificial turf is associated with less comfort and more pain during training in young soccer players. The use of SAIs led to lower pain intensity, highlighting a protective role of the insoles after 6 weeks of training on artificial turf.
Background: The use of cushioned or shock-absorbing insoles has been suggested as a mechanism to reduce the impact forces associated with running, thereby protecting against overuse injuries. The purpose of this study was to determine whether the use of cushioned insoles reduced impact forces during running in healthy subjects.
Methods: Sixteen recreational runners (9 females and 7 males) ran at a self-selected pace for five trials with and without the use of cushioned insoles. During each trial, ground reaction forces, tibial accelerations, lower-extremity kinematics, and subject-perceived comfort were recorded. All variables were tested with the level of statistical significance set at α = .05.
Results: The use of cushioned insoles resulted in significant reductions in mean vertical ground reaction force peak impact (6.8%) and ground reaction force loading rate (8.3%), as well as peak tibial acceleration (15.8%). Spectral analysis of the tibial acceleration data in the frequency range associated with impact accelerations (12–25 Hz) revealed no change in the predominant frequency or the power of the predominant frequency. The knee flexion angle at initial contact and perceived comfort were similar for the two conditions.
Conclusions: This study demonstrates the effectiveness of one type of cushioned insole in reducing peak impact force and tibial acceleration at initial foot-ground contact during running. The impact reduction observed was independent of knee kinematic adjustments or changes in perceived comfort. Further study is required to determine whether the reduction in loading that accompanied the use of the cushioned insoles can affect the incidence of running-related injuries. (J Am Podiatr Med Assoc 98(1): 36–41, 2008)
Background: The medial longitudinal arch of the foot is important because it helps protect the foot from injury. Researchers have developed many measures to quantify the characteristics of the arch, and there is ongoing debate about the suitability of these different metrics. This article compares the various measures related to the foot arch, including a new metric, the midfoot dorsal angle, and then investigates the differences in the dimensional measures among various foot types.
Methods: The right feet of 48 healthy individuals (24 men and 24 women) were measured, and various metrics, including the arch height index, the navicular height to arch length ratio, the arch index, the footprint index, the subjective ranking, the modified arch index, the malleolar valgus index, and the midfoot dorsal angle, were determined.
Results: Correlation analyses showed that the arch index obtained from the inked footprint has a moderate to high correlation (Pearson correlation coefficients >0.50) with all measured foot-type metrics except for the malleolar valgus index. There were no differences in participant age, stature, weight, body mass index, foot length, foot width, and midfoot height among high, normal, and low foot arches. However, the high-arched group had significantly shorter arch lengths but larger navicular heights and higher midfoot dorsal angles compared with the low-arched group. There were differences in force distributions and peak pressures as well. The rearfoot had more loading and greater peak pressure whereas the midfoot had less load in the high-arched group compared with the low-arched group.
Conclusions: The midfoot dorsal angle may be an appropriate metric for characterizing the foot arch because it is quick and easy to measure, without the tedious procedures associated with area calculations and dimension measurements. (J Am Podiatr Med Assoc 100(1): 14–24, 2010)
Background: Foot orthoses have been described as a possible intervention for individuals with patellofemoral joint pain. No study has attempted to quantify the perceived comfort and support of foot orthoses when used as an intervention for patellofemoral joint pain.
Methods: A randomized case-control trial with crossover between contoured and flat orthoses was conducted on ten individuals with patellofemoral pain and ten healthy participants. All of the participants completed a comfort-support assessment and had in-shoe plantar pressure data collected before and after 3 weeks of wear. A 1-week washout period was used to minimize any continued treatment effect between orthotics testing. The patellofemoral pain group also completed a numeric rating scale to assess pain reduction after using each orthosis.
Results: All of the participants perceived that greater support was provided by the contoured orthoses in the heel and arch regions. Even with a 30% difference in material hardness between the two orthoses, all of the participants rated cushioning as equivalent. Six individuals in the patellofemoral pain group reported a clinically significant reduction in knee pain as a result of wearing foot orthoses.
Conclusions: A key factor in the selection of contoured foot orthoses versus flat inserts is the amount of support that an individual perceives in the arch and heel regions. In addition, clinicians using foot orthoses as an intervention for patellofemoral pain should expect an individualistic, nonsystematic response. (J Am Podiatr Med Assoc 101(1): 7–16, 2011)