Do Orthotics with a Metatarsal Pad Decrease Pain and Fear of Falling in Older Adults? A Randomized Control Trial

Abstract Aims This randomized control trial compares the effects of orthotics, with and without metatarsal pads, on pain and fear of falling in older adults (NCT04894396). Methods 206 participants over 60 years old received either an Aetrex L2305 Orthotic with metatarsal pads (intervention) or an Aetrex L2300 Orthotic without metatarsal pads (control). Outcome scores were collected at baseline and at six weeks. Results Both the intervention and control groups reported significant improvements in pain in the back, hips, knees, ankles, and feet, measured on a Numerical Rating Scale (p < 0.001). Foot pain and foot function subscales of the Foot Health Status Questionnaire and the Short Falls Efficacy Scale International also significantly improved in both groups (p < 0.001). Between-group differences were not statistically significant for any outcome (p > 0.05). Conclusions Orthotics, with and without metatarsal pads, decrease pain and fear of falling in older adults.


Introduction
One in four people over the age of 45 experience frequent foot discomfort. 1 In older adults, foot pain can lead to a variety of consequences, such as reduced activity, reduced stability, and poor mental health.In a cross-sectional study containing 1,464 men and 1,857 women, both males and females with moderate foot pain were twice as likely to report depressive symptoms as compared to those with no foot pain. 2 Generalized musculoskeletal (MSK) pain is also highly prevalent in older adults, with rates of persistent MSK pain ranging from 40% to 60%. 3 Persistent general musculoskeletal pain is a threat to healthy aging and is associated with reduced mobility, frailty, risk of falls and even impaired cognitive function. 3nother substantial health concern in older adults is falling.One-third of older adults experience one or more falls each year, resulting in serious injuries, 4 such as hip fractures, of which 95% are caused by falls. 5The outlook for patients following a hip fracture is generally poor, with mortality rates of between 15% and 36% one year from injury. 6 healthy gait involves all four regions of the foot: the rearfoot, midfoot, forefoot, and toes. 7Foot pain can alter biomechanics, resulting in abnormal gait due to compensatory mechanisms.This can affect stability and increase the risk of falls. 8,9Reduced stability is also associated with fear of falling. 10Fear of falling is defined as a worry about falling, which may cause a person to avoid activities even though they remain capable of performing them. 11Where fear of falling results in activity avoidance, frailty, and an increased risk of falling follows. 12In addition, significant correlations have been found between fear of falling and foot impairment, 13 with foot pain more than doubling the risk of falling. 9he foot, by being the only source of contact with the ground during weight-bearing, provides imperative sensory feedback concerning body positioning that is vital for balance and stability. 14The foot also contributes to stability by supporting the body via the ligaments and bones within the arch's architecture. 14Unintentional injuries are the seventh leading cause of death in older adults, and falls are the greatest contributor to this mortality. 15Hence, it is important that modalities which effectively may reduce foot pain and fear of falling in older adults are investigated.
Orthotics are a noninvasive modality that can reduce pain, enhance proprioception, correct weight distribution, and provide support to the arch.Orthotics brace the arch and increase the contact surface area of the foot, which may enhance the sensory output and improve proprioception and stability (Figure 1A).Orthotics may also increase awareness of foot positioning. 16These benefits may reduce fear of falling.In addition, orthotic use may improve weight distribution to alleviate plantar pressure in the foot, a potential benefit for those with foot pain. 17Orthotics that include a metatarsal pad are also used in the management of foot pain and have been associated with reduced foot pain and improved balance. 18ew studies have investigated the effects of orthotics, either with or without a metatarsal pad, on perceived foot pain specifically, rather than plantar pressure.Although plantar pressure is related to foot pain, 17 it may be beneficial for a study to assess the effects of orthotics on perceived foot pain directly.Furthermore, no investigations have directly compared orthotics with and without metatarsal pads.Therefore, the current study will further add to the body of evidence regarding the effects of prefabricated orthotics, with and without a metatarsal pad, on perceived foot pain and fear of falling in older adults.

Materials and methods
This randomized control trial was conducted over six weeks.The primary objective was to investigate and compare the use of a prefabricated orthotic, with and without a metatarsal pad, in alleviating generalized musculoskeletal pain, foot pain in particular and reducing fear of falling in older adults.The study received ethical approval on the 10th of May 2021 from the Wales Research Ethics Committee 1 (REC reference number: 21/ WA/0106, IRAS project ID: 297189).Guidelines regarding research trials with human participants have been adhered to.This study was registered on clinical trials on May 20th, 2021 (Clinical Trials Number: NCT04894396).

Data monitoring & stopping guidelines
A data monitoring committee consisting of an independent doctor not part of the research team, a medical statistician, and patients met throughout the study duration to check the legitimacy and reliability of the data and to identify any significant adverse outcomes, if any.

Recruitment
A sample size calculation was performed using a target of 1.5 point change in the primary outcome (NRS pain score), which is the minimal clinical difference as recommended in the literature, 19 with a significance level of 5% and a target of 80% power.When allowing for a 20% drop-out rate, a requirement of 103 participants per group was identified, resulting in a total sample size of 206 participants.Participants were voluntarily recruited through online advertisements and leaflet drops distributed to areas surrounding the research site.Respondents were provided with a participant information sheet by post or email.Subsequently, an in-person consultation with the lead investigator was arranged, where participants were assessed for eligibility and had the opportunity to discuss questions before written consent was obtained.
Participants were required to be 60 years old or older, living in a community-based setting, capable of ambulation, and have self-identified foot pain.Participants were excluded if they had any history of previous foot surgery, compromised skin integrity of the lower limbs, peripheral neuropathy, lack of sensation in the feet, the current use of prescription orthotics, or self-reported inability to follow the instructions and procedures of the protocol.

Randomization
Once recruited, participants were randomized into one of two groups using a 1:1 allocation: the intervention group or the control group.The intervention group received the orthotics with a metatarsal pad (Aetrex L2305 Premium Memory Foam Orthotics), and the control group (Group B) received neutral orthotics with no metatarsal pad (Aetrex L2300 Premium Memory Foam Orthotics).The orthotics are depicted in Figure 2. Group allocation was executed via pre-filled, shuffled, sealed and opaque envelopes containing labels stating either 'MP' , denoting metatarsal pad (Intervention group -Group A), or 'No MP' denoting no metatarsal pad (Control group -Group B).The participant selected an envelope from random, the label inside assigning the participant to their group.Blinding of participants and researchers was not possible due to the nature of the study, given that the inclusion/exclusion of a metatarsal pad is obvious.

Data collection
Basic demographic information was collected from participants upon recruitment.All participants provided data for all outcomes at baseline and again at six weeks.

Primary outcome measure
Pain scores in the back, hips, knees, ankles, and feet were collected using 0-10-point Numerical Rating Scales (NRS), with 0 representing 'no pain' and 10 representing 'extremely severe pain' .Participants were required to indicate the level of pain they experienced in these locations over the last seven days.The NRS is a subjective measure of pain, validated in the literature. 20

Secondary outcome measures
Foot pain and foot functionality scores were collected via the Foot Health Status Questionnaire (FHSQ). 21Only the foot pain and foot functionality subscales of the FHSQ were used in the study.Each of these subscales was derived from responses of four 5-point Likert scales, ranging from 'no problems, pain or limitations' to 'severe problems, pain or limitations' .Foot function questions queried participants on whether their foot health limits their functional ability.A dedicated software programme developed by the creators of the FHSQ was then used to calculate an overall score based on the participants' answers.This overall score ranged from 0, representing 'worst foot health' , to 100, representing 'best foot health' .The FHSQ has been shown to have high responsiveness, retest reliability and construct validity. 22,23ear of falling was measured using the Short Falls Efficacy Scale International (Short FES-I), a 7-item version of the FES-I that is used to predict the risk of future falls, muscle weakness, frailty, and overall disability.The Short FES-I is scored from 7 (no concern about falling) to 28 (severe concern about falling).The Short FES-I can effectively predict disability, frailty and falls and has been validated for community-dwelling older adults. 24,25articipants were given the choice of submitting data via either online forms at smartsurvey.co.uk or paper forms provided and returned by post according to their preference.Data collection began in August 2021 and ended in September 2022.

Statistical analysis
To compare scores of all outcomes at baseline and follow-up, and the change between groups, along with significance, independent sample t-tests were used.For the results obtained from the NRS, Wilcoxon Sign-Rank tests were used to establish the significance of changes in musculoskeletal pain within groups, and Mann-Whitney U tests for the significance between groups.To determine the significance of changes within groups for foot pain/foot function and fear of falling, as assessed by the FHSQ and Short FES-I, respectively, paired sample t-tests were used.
The statistical methods of this study were reviewed by an independent statistician from the Department of Biostatistics, University of Liverpool.The full trial protocol can be accessed at: https://clinicaltrials.gov/ct2/show/ NCT04894383

Results
Two hundred and six participants were recruited for this randomized control trial, with 103 randomized to the intervention group with the metatarsal pad (MP) and 103 to the control group without the metatarsal pad.Throughout the study, 19 participants withdrew (nine from the intervention group with the metatarsal pad and ten from the control group without the metatarsal pad).Hence, 187 participants were included in the analysis (drop-out rate of 9.2%).Participant flow, including numbers, allocations, withdrawals and reasons, and analysis are detailed in Figure 3.
Basic demographic data for the 187 participants included in the analysis are shown in Table 1.Neither age nor gender was significantly different between groups at baseline (p < 0.05).
Results for each of the NRS pain scores for both groups are outlined in Table 2, along with the range, median change, and significance.The data was not normally distributed, hence the use of medians for this measure.Both the intervention group with the metatarsal pad and the control group without the metatarsal pad experienced significant reductions in pain in the back, hips, knees, ankles, and feet, although between-group differences were not statistically significant.
Results for the pain subscale of the FHSQ, functionality subscale of the FHSQ, and Short FES-I are outlined in Table 3, along with standard deviations, the mean change, and significance.After six weeks, both the intervention group with the metatarsal pad and the control group without the metatarsal pad reported significant improvements in foot pain and foot function, as assessed by the FHSQ.Between-group differences were not statistically significant.Nevertheless, on this measure, the intervention group with the metatarsal pad did report slightly greater reductions in pain and greater improvements in function following six weeks of orthotic use.Both the intervention group with the metatarsal pad and the control group without the metatarsal pad also experienced significant decreases in fear of falling, as assessed by the Short FES-I, with no statistically significant difference between groups.However, participants in the intervention group with the metatarsal pad did report a slightly greater decrease in fear of falling at six-week follow-up.

Discussion
This randomized control trial investigates the effects of Aetrex prefabricated orthotics, with and without a metatarsal pad, on generalized musculoskeletal pain, foot pain, in particular, foot functionality and fear of falling in older adults.

Orthotics for back pain
Analysis of the data shows that both the intervention group with the metatarsal pad and the control group without the metatarsal pad reported significant improvements in back pain.Mulford et al. 26 investigated the effects of arch supports without metatarsal pads on balance and pain in the back and lower extremities of older adults aged between 60 and 87 years old, all of whom were fitted for arch supports.Balance, functional mobility, and self-reported pain in the back and lower extremities were measured three times; without arch supports, immediately following the addition of arch supports inside participants' shoes and at six weeks.Pain in the feet, ankles, knees, hips, and back was reported on the Numeric Pain Distress Scale (NPDS).Like the NRS used in our study, this asked participants to rate their pain on a scale of 0 to 10, with 0 representing 'no pain' and 10 representing 'extremely severe pain' .From preintervention to following six weeks of arch support use, back pain significantly decreased. 26Cambron et al. 27 assessed the effects of custom-made shoe orthotics, with and without chiropractic treatment, on chronic low back pain in 225 adults aged between 18 and 86 years.Participants were randomized into one of three groups, receiving either shoe orthotics, shoe orthotics plus chiropractic manipulation, or no care.Perceived back pain was reported on a Numerical Pain Rating Scale of 0 to 10, and functionality was assessed by the Oswestry Disability Index.Compared to no care, the shoe orthotics significantly improved chronic low back pain and function at six-week follow-up.As compared to shoe orthotics only, the incorporation of chiropractic treatment significantly improved function further.However, the addition of this treatment had no effect on pain. 27

Orthotics for foot pain/function and Ankle pain
With regard to foot pain, both the groups with and without metatarsal pads reported significant improvements in NRS scores and the pain subscale of the FHSQ outcome measure.Arch support increases the contact area for the foot, distributing weight more evenly and resulting in decreased plantar pressure, potentially reducing foot pain. 17Bonanno et al. 17 assessed the effects of various shoe inserts on plantar pressure in 36 older adults (aged 65+) with plantar heel pain.The inserts evaluated included a silicon heel cup, a soft foam heel pad, a heel lift and prefabricated foot orthotics.All inserts reduced plantar pressure significantly, with the greatest reduction occurring with prefabricated orthotics. 17In the current study, although between-group differences were non-significant, the intervention group with the metatarsal pad displayed a slightly greater reduction in foot pain on the FHSQ than the control group without the metatarsal pad.Forefoot pain in older adults is associated with higher plantar pressures under the metatarsal heads. 9,31Metatarsal pads act by redistributing plantar pressure from directly under the metatarsal heads to a more proximal and wider area (Figure 1B). 32In addition, metatarsal pads widen the forefoot during gait, creating extra space between the heads of the metatarsals and potentially further contributing to pain reduction. 33Lee et al. 34 compared the effects of various types of forefoot pads on plantar pressure in older adults with forefoot pain.Thirty-seven adults with a mean age of 73.5 years were included.Whilst having their plantar pressure data recorded, each participant walked along an 8 m walkway under five forefoot pad conditions.Compared with a shoe-only condition (control), all variations of forefoot padding reduced forefoot peak pressure and maximum force. 34In a follow-on study, Landorf et al. 35 aimed to assess the effects of various metatarsal pads on forefoot plantar pressure.Participants included 36 adults aged 65 or older with a history of forefoot pain.Again, each participant had their plantar pressure data recorded whilst walking along an 8 m walkway using the different forefoot pads.All metatarsal pad conditions significantly reduced plantar pressure compared to the no-pad condition (control). 35However, both of these studies assessed forefoot pads independently and not as a component of prefabricated orthotics with arch support and a cupped heel.In a study that assessed orthotics more similar to those used in the current study, de Morais Barbosa et al. 18 investigated the effects of insoles with both medial arch support and metatarsal pads on balance, foot pain, and disability in older women with osteoporosis.The effects of the orthotics with metatarsal pads were assessed as compared to a no orthotics condition (control).After four weeks, only the intervention group with the orthotics showed significant improvements in foot pain, as assessed by a Numerical Pain Scale. 18ike the current study, orthotics without metatarsal pads have also been shown to reduce foot pain in the literature.Mulford et al. 26 reported significant improvements in foot pain after 6 wk of arch support use. 26 Foot function, as assessed by the FHSQ, also significantly improved in both groups with and without the metatarsal pad, although no significant between-group difference was observed.Mannikko et al. 36 investigated the effects of custom-made metatarsal pad insoles on functional ability and pain in 25 patients with metatarsalgia (mean age = 56 years).Function, as evaluated by The American Orthopedic Foot & Ankle Society score, was found to significantly improve following the use of metatarsal pads.In addition, pain scores on a Numeric Rating Scale also showed significant improvement. 36Rao et al. 37 investigated the functional outcome following the use of custom-made orthotics without a metatarsal pad in 25 female patients with midfoot arthritis.Functional outcomes were evaluated using the Foot Function Index-Revised scale.The study found that, following four weeks of orthotic use, functionality scores improved significantly by 12%. 37he current results also show that ankle pain was reduced significantly in both groups with and without a metatarsal pad.Mulford et al. 26 identified non-significant improvements in ankle pain. 26

Orthotics for fear of falling, balance, and falls
Full-length contoured orthotics increase the surface area of the foot in contact with the ground.The increased contact area can enhance the afferent somatosensory feedback, potentially contributing to improved balance control. 16In the current study, both groups reported significant reductions in fear of falling via the Short FES-I.Fear of falling has been associated with greater sway during gait, which may suggest decreased stability and increased risk of falls. 10Hence, perceived improvements in balance may translate to reduced fear of falling.Therefore, the improvements in fear of falling observed in the current study may be a result of the participants perceiving improved stability on using orthotics.The study by de Morais Barbosa et al. 18 found that the use of orthotics with metatarsal pads for four weeks significantly improved balance in osteoporotic older women aged 60 and over. 18However, a 2016 systematic review by Aboutorabi et al. 16 found that previous research into orthotics and balance in older adults is of low quality, containing limitations including a lack of randomization, poor internal validity, and a lack of parity between groups. 16A more recent systematic review, conducted in 2020 by Ma et al. 38 , investigated the effects of various insoles on static and dynamic balance in community-dwelling older adults.The review identified that variations of insoles which incorporated heel cups and arch supports improved postural balance.Whilst the authors were able to draw these conclusions, they stated that further clinical trials were required to substantiate the evidence. 38In the current study, participants in the intervention group with the metatarsal pad reported slightly greater reductions in fear of falling after six weeks.This may be linked to the large concentration of mechanoreceptors in the metatarsophalangeal joints of the foot.A metatarsal pad that increases the contact area of the forefoot under these joints may increase the volume of proprioceptive and afferent information, thus improving balance and, potentially, reducing fear of falling. 18lder adults may have a non-neuropathic loss of cutaneous sensation in the feet, which can result in decreased balance and increased falls. 39Perry et al. 39 investigated the effect of insoles with a raised ridge around the perimeter on stability in older adults.The edge provided a contrasting contour and helped in improving stability and decreasing falls. 39We propose that the metatarsal pad, placed in an area with the greatest concentration of sensory endings in the feet, acts as a 'central post' , providing increased skin indentation and enhanced stimulation to the local mechanoreceptors.This may have elicited greater neuron activity, contributing to the greater reductions in fear of falling observed in the intervention group with the metatarsal pads.

Strengths and limitations
The non-significant differences in age and gender between the two groups at baseline add to the generalizability of the study results, and the current study's use of a randomization process ensures parity between the two groups.Though many studies have assessed the effects of orthotics on plantar pressure, few studies have investigated their effects on perceived foot pain.Although increased plantar pressure is associated with foot pain in older adults, 9 the results of this study further the previous findings concerning the effects of orthotics on perceived foot pain specifically.A search of published scientific literature also shows that, unlike the current study, previously, no research has directly compared orthotics with metatarsal pads to orthotics without, and their potential effects on fear of falling.
A limitation in this analysis is the potential for bias due to the lack of blinding of participants and researchers following group assignment.Participants in the intervention group may have been influenced by the placebo effect, believing that the inclusion of the pad would produce the observed benefits.Another limitation is that the study did not include a control group without orthotics.In addition, the current study does not consider the number of falls that occurred.Therefore, the results can only be interpreted regarding fear of falling and not falling itself.Hence, including a fall chart as a measure, or objective balance tests, is a consideration for future research.Furthermore, due to the adverse effects foot pain can have on mental health, 2 the provision of a questionnaire to assess mental well-being before and after the intervention could be considered in further studies.It may have also been beneficial to collect data on body mass index (BMI) to ascertain the influence this may have on the efficacy of orthotics during weight-bearing.Moreover, a lack of objective data concerning the effects of orthotics on balance in older adults has been highlighted as a limitation of the preexisting literature. 16Hence, in the present study, the collection of objective motor-control data, for example via force plate or electromyography, could improve the validity of the results.

Conclusion
The results of this study indicate that prefabricated orthotics, both with and without a metatarsal pad, significantly reduce pain in the back, hips, knees, ankles, and feet of older adults.In addition, findings reveal that foot-health-related functionality and fear of falling also significantly improve with the use of these orthotics.Although no between-group differences reached statistical significance, reductions in foot pain, improvements in function, as assessed by the FHSQ, and decreases in fear of falling, as assessed by the Short FES-I, were slightly greater in the intervention group, suggesting that orthotics with a metatarsal pad may be superior.In conclusion, prefabricated orthotics may be a cost-effective and readily available modality to improve pain, function, and fear of falling in older adults.

Figure 1 .
Figure 1.Orthotics reduce pressure by increasing the contact area of the foot through the arch and heel (green areas), distributing weight across a wider area (a).Orthotics with a metatarsal pad may reduce pressure from directly under the metatarsal heads to a more proximal and wider area (B).

Figure 2 .
Figure 2. aetrex l2305 Premium Memory Foam Orthotics with the metatarsal pad, provided to the intervention group (a), and aetrex l2300 Premium Memory Foam Orthotics without the metatarsal pad, provided to the control group (B).

Table 1 .
table of participant demographics.

Table 2 .
table of nrs pain scores analysis.