Foot Mobilization and Exercise Program in Combination with Toe Separator Improves

Transcription

1 ORIGINAL ARTICLE Foot Mobilization and Exercise Program in Combination with Toe Separator Improves Outcomes in Women with Moderate Hallux Valgus at the One-Year Follow-Up A Randomized Clinical Trial Sahar Ahmed Abdalbary, PhD* *Faculty of Physical Therapy, Department of Physical Therapy for Musculoskeletal Disorder and its Surgery, Cairo University, 2, street 107, Maadi, Eletehad Square, Cairo, Egypt. ( saharabdalbary@yahoo.com) Background: Few studies have documented the outcome of conservative treatment of hallux valgus deformities on pain and muscle strength. Our objective in this study was to determine the effects of foot mobilization and exercise program, in combination with use of a toe separator, on symptomatic moderate hallux valgus in female patients. Methods: As part of the randomized clinical trial, 56 adult female patients with moderate hallux valgus were randomly assigned to one of two groups: 36 sessions for 3 months or no intervention (waiting list). All patients in the treatment group had been treated with mobilization for all the joints of the foot, strengthening exercises for the plantar flexion and abduction of the hallux, toe grip strength, stretching for ankle dorsiflexion, plus use of a toe 1

2 separator. Outcome measures were pain and American Orthopedic Foot and Ankle Society (AOFAS) scores. Objective measurements included ankle range of motion, plantar flexion and abduction strength, toe grip strength, and radiographic angular measurements. Outcome measures were assessed by comparing pre-treatment, post-treatment, and a one-year followup after the intervention, by an assessor blinded to the treatment allocation of the patient. Mixed-model analyses of variance were used for statistical assessment. Results: Patients who were treated with 3 months of foot mobilization and exercise program combined with the use of a toe separator experienced greater improvement in pain 2.4±1, AOFAS score, ankle range of motion 74.5±2, plantar flexion and abduction of the hallux strength, toe grip strength, and radiographic angular measurements, than those who did not receive an intervention, at both 3 months and one year post-intervention (P < for all comparisons). Conclusions: The effect of these results support the use of a multi-faceted conservative intervention to treat moderate hallux valgus, although more research is needed to study which aspects of intervention were most effective. Trial registration Ethics, Committee Approval for the study was obtained from the institutional review board of the Department of Physical Therapy for Musculoskeletal Disorders and its Surgery of the Faculty of Medicine, Cairo University (Approval number334, approval date, 20 June 2012). 2

3 Hallux valgus is a common structural foot deformity in which the angular deviation of the hallux is greater than 15º toward the lesser toes in relation to the first metatarsal bone; it appears as a medial bony prominence of the first metatarsal head [1]. The hallux valgus angle is the angle between the bisection line of the first metatarsal bone and the proximal phalanx [2]. Normal valgus is a deformity with many etiologies such as familial history, women, occupational foot stress, shoe shape, and style, a long first metatarsal, and an oval or curved metatarsophalangeal joint articulation surface [4]. Hallux valgus has been stated to have a prevalence of 21% to 70% based on epidemiologic studies [5]. Women are significantly more likely to develop hallux valgus than men [6]. Hallux valgus is a major reason for orthopedic foot and ankle surgery each year [7], and is accompanied by functional disability, foot pain, impaired balance, and high fall risk in older adults [8]. Available treatments for hallux valgus are classified into operative and non-operative treatments. Although surgery is considered the most common approach, it is expensive and may cause significant complications [9]. Non-operative treatments aim to decrease the angle of the first metatarsal big toe by stretching the contracted soft tissue around the joints by using night splints, improving muscle strength through foot exercises, or resolving abnormal function with orthosis [10]. The dynamics of hallux valgus deformity are explained by examining the muscles of the first ray. The tendons and muscles that move the big toe are arranged around the 3

4 metatarsophalangeal joint in four groups, the long and short extensors, the short flexors, and the two tendons of the abductor and adductor halluces [6]. The intrinsic muscles of the foot when subjected to unsuitable footwear or because of inherent fragility may chronically malfunction and become an important factor in the pathomechanics of hallux valgus and lesser toe deformity [10]. A toe separator can correct the alignment of the toes and this functional realignment helps the foot to propel better in gait cycles [11]. The purpose of this randomized clinical trial was to determine the effect of the foot mobilization and exercise program combined with the use of a toe separator to treat symptomatic moderate hallux valgus in female patients, after the end of treatment and at the one-year follow-up. In this study, we hypothesized that patients who participated in foot mobilization, exercise program, and additionally used a toe separator, would have greater improvement of symptomatic moderate hallux valgus in terms of pain, functional disability, muscle strength, and radiographic measurements of the big toe, than in patients who did not receive any intervention (natural course of the disease). Methods Design This was a randomized controlled clinical trial. Participants, inclusion and exclusion criteria 4

5 Fifty-six female patients with a diagnosis of symptomatic moderate hallux valgus were included in this study. All patients had been referred by a physician to the outpatient physical therapy clinic between September9, 2012, and August30, Only 21% of eligible patients participate. All the participants had pain and functional disability associated with symptomatic moderate hallux valgus deformity. In addition, all patients reported that they were not undergoing physical therapy, or using orthotics or dynamic splint as treatment for hallux valgus. The inclusion criteria were adult female patients, as there is an increased incidence of symptomatic hallux valgus in women [12]. Patients who met the following criteria were excluded: previous foot surgery, underlying ankle deformity, or pathologic hindfoot or midfoot deformities, or any deformity of the hallux other than valgus deformity. Patients with systemic pathologies such as rheumatoid arthritis or gout were also excluded. Patients who were using anti-inflammatory drugs or analgesics or where manual therapy was contraindicated, were excluded [13]. Pregnant women were excluded because plain-film X-rays are contraindicated during pregnancy. Measurement procedures All measurements were made by an examiner with 20 years of experience, who is not the author. The measurements included: (1) Pain using a visual analog scale, (2) Functional assessment, using the metatarsophalangeal-interphalangeal score of the AOFAS, (3) Radiographic measures of the hallux valgus angle and the first-second intermetatarsal angle, (4) The goniometric measurement for the passive range of motion of dorsiflexion of the ankle, (5) 5

6 The first metatarsophalangeal joint plantar flexion and abduction muscle strength, and (6) Toe grip strength. All measurements were made two days before the first session of treatment, at the end of the last session, and one year after the treatment, for the treatment as well as the control group. Foot pain and functional disability The evaluation was performed on all patients. Pain was quantified with a 10-point visual analog scale (with 0 indicating no pain and 10 indicating severe pain). A score was determined by using the hallux interphalangeal joint scale of the American Orthopedic Foot and Ankle Society (AOFAS) [14]. This 100-point scale assesses subjective and objective factors. The numerical score is composed of a separate section for pain (0 40 points), function (0 45 points), and alignment (0 15 points). These scores were calculated pre-treatment, posttreatment, and at one-year follow-up. Demographic data of patients The patient demographics include women, mean age of 45.7 ± 6.8 years for the treatment group and 45.5 ± 6.2 years for the control group, height, weight, and BMI (25.6 ± 1.9 kg/m 2 for the treatment group and 25 ±2.4 kg/m 2 for the control group) (Table 1). Radiographic examination 6

7 Standardized antero-posterior weight bearing radiographs of all feet were taken. The hallux valgus angle and first-second intermetatarsal angle were measured according to the guidelines set forth by the AOFAS committee on angular measurements [2]. Goniometric measurements of passive ankle dorsiflexion Patients were in the prone position with the knees extended and the feet over the edge of a plinth. The neutral position of the subtalar joint was identified and then the foot was dorsiflexed until a firm end-point was felt. The goniometer, which was marked in 1 increments, was positioned on the lateral side of the ankle with the axis over the lateral malleolus [15]. Hallux plantar flexion and abduction strength measurements Hallux plantar flexion and abduction strength was evaluated using 50 kg load cells (GK , Gedge Systems, Melbourne, Australia) mounted in a custom-built frame. This testing protocol has been previously described [16]. While the patient was seated with the knee in 30 of flexion and the lower leg and foot stabilized, using Velcro straps, the patient performed three isometric maximum voluntary contractions in hallux plantar flexion and abduction, and the maximum force achieved over three trials was used for analysis. Measurement of toe grip strength The dynamometer (T.K.K. 3362, Takei Scientific Instruments, Niigata, Japan), which was used to measure toe grip strength, has been reported to be reliable [17]. The patients sat upright on the chair without leaning on the backrest. Throughout toe-grip strength measurement, the hip and knees were both flexed approximately 90, and the ankles were placed in the neutral position and fixed with a strap. The first proximal phalanx was positioned 7

8 at the grip bar and the heel stopper was adjusted to fit the heel of each patient. The first toe was used as a benchmark to set up the testing position; the bar was then gripped with maximal effort using all toes. The examiner stabilized the toe grip dynamometer, while two toe gripstrength measurements were made for each foot. Randomization Following the baseline examination, patients were randomly assigned to receive treatment or no intervention (natural history of the disease), using a computer-generated table of randomized numbers created prior to the start of data collection, by an assistant to the author, who was not involved in the recruitment or treatment of patients. The randomized group assignments sequentially numbered index cards were placed in sealed, opaque envelopes. The author was blinded to the baseline examination findings. The envelope was opened and the treatment was carried out according to the assigned groups. Control group Patients in the control group were asked to avoid surgical and foot orthotic therapy during the follow-up period, and did not receive any intervention, so that the natural course of the condition could be determined. These patients were asked to continue their antiinflammatory medications and normal activities without exacerbating their symptoms or seeking additional treatment during the study period. Treatment program 8

9 All patients in the treatment group wore a toe separator made of silicon material (Voberry silicone bunion toe separator pain relief spreader shield gel toe separator). The patients were required to wear the toe separator for > 8 hours per day. The physical therapy program consisted of 3 sessions per week for 12 weeks. The author performed this treatment. The physical therapy program was started with manual therapeutic interventions, which were performed for all metatarsophalangeal joints. These manipulations focused on an improvement of flexion and included caudal sliding of the proximal phalanx to improve extension. In addition, oscillating traction was performed to activate the mechanoreceptors that inhibit the afferent pain sensors. The treatment program also included mobilization of the first metatarsophalangeal Lisfranc, transverse tarsal, subtalar, and ankle joints [7]. Non-weight bearing tendoachilles stretching was performed manually by the therapist. The patients were instructed to lay supine and the therapist did the stretching manually; the stretching was repeated 5 times during each session and held for 15 seconds each time. The patients were advised that the stretching should be pain free, although a small degree of unpleasantness was allowed [18]. Hallux plantar flexion strengthening exercises consisted of 10 isometric contractions, performed with a hold time of 10 seconds each. The physical therapist provided resistance manually to the entire phalanx with the metatarsophalangeal joint in neutral. Patients were instructed not to flex the interphalangeal joint during the exercise. The isometric contraction occurred at the metatarsophalangeal joint. We increased the repetition by one set every week, 9

10 and by the last week, it had increased to 8 sets of 10 repetitions with 12 seconds of rest between each set [19]. For the hallux abduction strengthening exercise, the patients maintained a long sitting position, the heel was held and pressure was exerted on the first metatarsal and proximal phalanx of the medial axis to create an abduction of the big toe [20]. Ten isometric contractions were performed with a hold time of 10 seconds each. We increased the repetition every week by one set, and by the last week, the exercise had increased to eight sets with 10 repetitions allowing 12 seconds of rest between each set. For the towel curls exercise, the patients were instructed to place a towel on the hardwood floor and place their toes on the edge of the towel. They were then instructed to drag the towel under their foot by flexing their toes, generating a strong grip on the fabric for 5 seconds per repetition. The patients were instructed to perform 10 repetitions with 5 seconds of rest between each set [21]. Outcome measures Data was collected pre-treatment and post-treatment (after 24 sessions), and at oneyear follow-up. Therefore, three sets of data were available for analysis for each intervention and for both groups. Patients with hallux valgus consult with musculoskeletal practitioners such as podiatrists and physiotherapists, mainly because of pain and functional disability. Therefore, the outcome measures selected were pain, measured using a visual analog scale, functional disability, measured with the AOFAS scale, radiographic measures (hallux valgus angle and the 10

11 first-second intermetatarsal angle), range of motion of ankle dorsiflexion, plantar flexion and abduction hallux muscle strength, and toe grip strength. Statistical analysis Statistical analysis was performed with use of SPSS version 18.0 for windows (SPSS Inc., Chicago, IL). Data were statistically described in terms of mean, standard deviation, and 95% confidence interval, which were evaluated for each variable. Sample size was based on a prior power calculation using standard deviations obtained from preliminary data analysis (n = 56). We determined that 56 patients in two groups would provide 80% power to detect a difference of 11 mm between patients on the 100 mm pain visual analog scale (alpha 0.05) [22]. The Kolmogorov-Smirnov test showed a normal distribution of quantitative data. As the participants received intervention only for one foot And it was the worse affected limb, we used a 3-by-2 mixed-model of variance (ANOVAs), with time (baseline, 3 months after therapy, and one year after therapy) as the within subject factor and group (treatment, control). We also used the unpaired Student s t-test at the beginning to compare the treatment and control groups before the intervention. Statistical significance was defined as P value < Results Fifty-six female patients (56 feet) with symptomatic moderate hallux valgus screened by eligibility criteria agreed to participate in this study. They were randomized to either the treatment group (program of exercises combined with use of a toe separator) (n = 28) or control (n = 28) group. Baseline features between the two groups were similar for all variables 11

12 (Table 1). The 3-by-2 mixed-model ANOVA revealed significant group by time interaction (P < 0.001) for all variables measured, in which patients were treated with the foot mobilization and exercise program in combination with use of a toe separator (Table 2). Radiographic measurements of treatment group (n=28) The mean hallux valgus angle before the treatment was 32.7 ± 4.2. After the treatment, the angle decreased to 23.8 ± 3.1 (P < 0.001) and the improvement remained stable; at one year follow-up, the angle was 25.8 ± 2.1 (P < 0.001). The first-second intermetatarsal angle before the treatment was 14 ± 1 and after the treatment was 11.8 ± 0.5 (P < 0.001) and the improvement remained stable; at one year, it was 12 ± 0.9 (P < 0.001). Pain measurements using the visual analog scale for treatment group (n=28) The mean pre-treatment pain score was 5.6 ± 1 points (range 0 10 points). The mean score on the 10-point visual analog scale post-treatment was significantly decreased to 2.2 ± 1 points (P < 0.001) and the improvement remained stable; at one year, it was 2.4 ± 1 points (P < 0.001). Functional disability measured by AOFAS for treatment group (n=28) The mean pre-treatment AOFAS score was 46.1 ± 1.4 points and after the treatment improved significantly to 76.2 ± 1.5 points (P < 0.001). The improvement remained stable; at one year, it was 74.5 ± 2 points (P < 0.001). Ankle dorsiflexion passive range of motion for treatment group (n=28) 12

13 The mean ankle dorsiflexion passive range of motion was 9.5 ± 1.2º before the treatment and 15.2 ± 2.1º after the treatment, which was significant (P < 0.001). The improvement remained stable; at one year, it was 13.2 ± 2.1º (P < 0.001). Hallux plantar flexion strength for treatment group (n=28) The measurements of hallux plantar flexion strength before the treatment were 50.4 ± 2.8 N and after the treatment significantly increased to 65.9 ± 5.6 N (P < 0.001). It remained stable; at one year, it was 62.9 ± 2 N (P < 0.001). Hallux abduction strength for treatment group (n=28) Hallux abduction strength before the treatment was 6.4 ± 1 N and after the treatment was 10.5 ± 1.6 N (P < 0.001). The improvement remained stable; at one year, it was 8.8 ±1.3 N (P<0.001). Toe grip strength for treatment group (n=28) The toe grip strength before the treatment was 65.2 ± 10.4 N and after the treatment increased to 98.1 ± 9.2 N (P < 0.001). The improvement remained stable; at one year, it was 93.1 ± 5.2 N (P < 0.001). Control group In the control group, there were no significant differences during the one year of waiting, despite an increase in the pain intensity, hallux valgus angle, and first-second intermetatarsal angle. There were also decreases in the AOFAS, ankle dorsiflexion, hallux plantar flexion and abduction strength, and toe grip strength (Table 3). 13

14 Comparison between the treatment group and control group after the treatment and oneyear follow-up These comparisons showed significant differences (P < 0.001) (Table 4 ) for hallux valgus angle, first and second intermetatarsal angle, Pain m AOFAS, ankle dorsiflexion, hallux plantar flexion and abduction strength, and toe grip strength. Discussion The findings of the present study support our hypothesis that foot mobilization and exercise program, combined with use of a toe separator, improves pain, functional disability, ankle dorsiflexion range of motion, hallux plantar flexion and abduction strength, toe grip strength, in addition to decreasing the hallux valgus and first-second intermetatarsal angles. Conservative treatment for symptomatic hallux valgus such as manual and manipulative therapy, compared with the outcomes of surgical approaches, provided an approximately 15 mm change in visual analog scale scores at follow-up [23,24]. This supports the development and testing of conservative treatments in the future. The cost savings over surgery and avoidance of post-surgical complications is expected to be significant. Our study tested results of an exercise program, in combination with use of a toe separator. Relief has been reported following manipulative therapy [25], and with the use of an insole accompanied by a toe separator for painful hallux valgus [26]. In the current study, the mean pain scores were significantly reduced from 5.6 ± 1 to 2.2 ± 1 points after treatment and continued to be stable at one-year follow-up. 14

15 There were significant associations between hallux valgus and pain, worsening function, and worsening foot health in subjects with moderate hallux valgus deformity [27]. The reported mean AOFAS scores after treatment increased from 46 ± 1.4 to 76.2 ± 1.5 and remained higher than the baseline measurement at one-year follow-up. Restricted ankle dorsiflexion may be associated with the development of hallux valgus [6]. We acknowledge the limitation of using a goniometer to assess ankle dorsiflexion in this study. Measurements done before the treatment and after the treatment showed that manual tendoachilles stretching was efficient in increasing the range of motion from 9.5 ± 1.2 to 15.2 ± 2.1º. We performed this stretching because the muscles of the leg contribute to supporting the alignment of the hindfoot, midfoot, and first ray [28]. The first ray is an inherently unstable axial array that relies on a fine balance between the static stabilizers (capsule, ligament, and plantar fascia), and dynamic stabilizers (peroneus longus and small muscles of the foot) to maintain its alignment [29]. People with moderate to severe hallux valgus had significantly less hallux flexor strength than those without hallux valgus [30]. We performed exercises to strengthen the plantar flexion of the hallux and they were effective in increasing the strength from 50.4 ± 2.8 to 65.9 ± 5.6 N. The abductor hallucis muscle, in addition to its action in maintaining the alignment of the toe, also has a splitting effect on the first metatarsal head. Acting in a line parallel to this bone and using the head of the first metatarsal as a fulcrum, the abductor hallucis pushes the first metatarsal toward the second metatarsal [6]. In measurements of the hallux abduction strength, there was significant increase after the treatment from 6.4 ± 1.1 to 10.5 ± 1.6 N. Many 15

16 studies used 50 kg load cells (GK Gedge Systems) to evaluate the strength of hallux plantar flexion and abduction [16,26]. Toe grip-strength of individuals with hallux valgus has been reported to be weaker than that in normal individuals [31]. Toe strength grip was measured before the treatment and there were significant increases in toe strength grip from 65.2 ± 10.4 to 98.1 ± 9.2 N after treatment. A toe grip dynamometer, which we used in our study, has been widely used in many studies [17,31,32]. 1 Toe curl exercises were successful in increasing toe grip strength, because they are used to strengthen the flexor digitorum longus and brevis, lumbricales, and flexor hallucis longus [33]. There is an association between the magnitude of the hallux valgus angle and the firstsecond intermetatarsal angle [34], and these findings were confirmed in our study. Before the treatment, the value of the hallux valgus angle was 32.7 ± 4.2º and the first-second intermetatarsal angle was 14 ± 1º, and after the treatment, there were concomitant decreases in both angles; the hallux valgus angle was 23.8 ± 3.1º and the first-second intermetatarsal angle was 11.8 ± 0.5º. In our study, we confirmed that a toe separator can correct the alignment of the toes and this functional realignment can help the foot to propel better in the gait cycles [11]. In this trial, we were able to evaluate the effectiveness of the treatment program. The treatment program showed considerable effectiveness in the outcome measures at one-year 16

17 follow-up, although we were unable to correct the deformity, and can be considered an option while waiting for surgery. We selected our sample from patients with moderate hallux valgus. The sample did not include patients with mild hallux valgus, because it was reported that there were no significant differences between those with mild hallux valgus and normal halluces in terms of muscle strength [16]. The main limitation of this study is that the AOFAS scoring system is yet to be validated; however, the AOFAS scoring system is being widely used. Reliability of measurement methods must be considered as a potential limitation in any clinical research. The same examiner, who has 20 years of experience, performed all measurements in our study. We need further studies to compare of different combinations of treatment to determine which combination is most effective. No one in our patient complaint from the toe separator and treatment group they continue to wear it after the 3 month of treatment till the last follow up. No patient were lost from the study and this strength of the study. All our patients instructed to wear shoes with a lower heal and broader toe box. Conclusions 17

18 The results of this randomized clinical trial suggest that the foot mobilization and exercise program, combined with use of a toe separator, decreases the pain intensity, functional disability, and radiographic measurements. It also increases the hallux plantar flexion and abduction strength, toe grip strength, and ankle dorsiflexion range of motion after the treatment and at one year of follow-up in female patients with moderate hallux valgus deformity, compared to a control group that did not receive any intervention. Further research is needed to evaluate the program with a longer follow-up. Financial Disclosure: None reported. Conflict of Interest: None reported. References [1] Nugyen US, Hillstrom HJ, Li W, et al. Factors associated with hallux valgus in populationbased study of older women and men: The Mobilize Boston Study. Osteoarthritis Cartilage. 2010;18:41 6. [2] Coughlin MJ, Saltzman CI, Nunley JA, 2 nd. Angular measurements in the evaluation of hallux valgus deformities: A Report of the Ad Hoc Committee of the American Orthopedic Foot & Ankle Society on angular measurements. Foot Ankle Int. 2002;23: [3] Coughlin MJ, Jones CP. Hallux valgus demographics, etiology, and radiographic assessment. Foot Ankle Int. 2007;28:

19 [4] Schneider W, Knahr K. Surgery for hallux valgus. The expectations of patients and surgeons. Int Orthop. 2001;6: [5] Roddy E, Zhang W, Doherty M. Prevalence and associations of hallux valgus in a primary care population. Arthritis Care &Res. 2008;34: [6] Mann R, Coughlin M. Hallux valgus etiology, anatomy, treatment and surgical considerations. Clin Orthop Relat Res. 1981;157: [7] Myer AJ, Adams MI, Sheridan MJ, Ahalt RG. Epidemiological aspects of the surgical correction of structural forefoot pathology. Foot Ankle Surg. 2009;48: [8] Menz HB, Roddy E, Thomas E, Croft PR. Impact of hallux valgus severity on general and footspecific health-related quality of life. Arthritis Care Res. 2011;63: [9] Sammarco GJ, Idusuyi CB. Complications after surgery of the hallux valgus. Clin Orthop Relat Res. 2001;391: [10] Hoffmeyer P, Cox JN, Blanc Y, Meyer JM, Taillard W. Muscles in hallux valgus. Clin Orthop Relat Res. 1988;232: [11] Teheraninasr A, Saeedi H, Forogh B, Bahramizadeh M, Kehyani RM. Effects of insole with toe separator and night splint on patients with painful hallux valgus: A comparative study. Prosthet Orthot Int. 2008;32: [12] Nix S, Smith M, Vicenzino B. Prevalence of hallux valgus in the general population: a systematic review and meta-analysis. J Foot Ankle Res. 2010;27:

20 [13] Plessis M, Zipfel B, Brantingham JW, Parkin-Smith G, Birdsey P, Globe G, Cassa T. Manual and manipulative therapy compared to night splint for symptomatic hallux abducto valgus: An exploratory randomized clinical trial. The Foot. 2011;21:71 8. [14] Kitaoka HB, Alexander IJ, Adelaar RS, Nunley JA, Myerson MS, Sanders M. Clinical rating systems for the ankle-hindfoot, midfoot, hallux, and lesser toes. Foot Ankle Int. 1994;15: [15] Diamond JE, Muller MJ, Sinacore DR. Reliability of a diabetic foot evaluation, Phys Ther. 1989;69: [16] Nix S, Vicenzino B, Smith M. Foot pain and functional limitation in healthy adults with hallux valgus: a cross-sectional study. BMC Musculoskelet Disord. 2012;13:197, [17] Uritani D, Fukumoto T, Matsumoto D. Intrarater and interrater reliabilities for a toe grip dynamometer. J Phys Ther Scie. 2012; 24: [18] Porter D, Barrill E, Oneacre K, May BD. The effects of duration and frequency of Achilles tendon stretching on dorsiflexion outcome in painful heel syndrome: a randomized, blinded, control study. J Foot Ankle Int. 2002;23: [19] Baechle TR, Erle RW, editors. Essentials of strength training and conditioning. (2 nd edition) Champaign, IL. Human Kinetics; [20] Heo H, Koo Y, Yoo W. Comparison of selective activation of the abductor halluces during various exercises. J Phys Ther Scie. 2011;23: [21] Lyn SK, Padilla RA, Tsang KK. Differences in static- and dynamic- balance task performance after 4 weeks of intrinsic-foot-muscle training: the short-foot exercise versus the towel-curl exercise. J Sport Rehabil. 2012;21:

21 [22] Gallagher EJ, Liebman M, Bijur PE. Prospective validation of clinically important changes in pain severity measured on a visual analog scale. Ann Emerg Med. 2001;38: [23] Torkki M, Malmivaara A, Sietsalo S, Hoikka V, Liappala P, Paavolinen P. Surgery vs orthosis vs watchful waiting for hallux valgus: A randomized controlled trial. JAMA. 2001;285: [24] Torkki M, Malmivaara A, Siesalo S, Paavolainen P. Hallux valgus: Immediate operation versus 1 year of waiting with or without orthoses: A randomized controlled trial of 209 patients. Acta Orthop Scan. 2003;74: [25] Brantingham JW, Guiry S, Kertzmann HH, Kite VJ, Globe G. A pilot study of the efficacy of a conservative chiropractic protocol using graded mobilization, manipulation, and ice in the treatment of symptomatic hallux abductovalgus bunion. Clin Chiropr. 2005;8: [26] Hurn SE, Vicenzino B, Smith MD. Functional impairments characterizing mild, moderate, and severe hallux valgus. Arthritis Care Res. 2015;67:80 8. [27] Cho NH, Kim S, Kwon D-J, Kim HA. The prevalence of hallux valgus and its association with foot pain and function in a rural Korean community. J Bone Joint Surg (Br). 2009;91B: [28] Glasoe WM, Phadke V, Pena VA, Nuckley DJ, Ludewing PM. An image based simulation study of tarsal kinematics in women with hallux valgus. Phys Ther. 2013;93: [29] Perera AM, Mason L, Stephens MM. The pathogenesis of hallux valgus. J Bone Joint Surg (Am). 2011;93: [30] Mickle KJ, Munro BJ, Lord SR, Menz HB, Steel JR. Toe weakness and deformity increase the risk of fall in older people. Clin Biomech. 2009;24:

22 [31] Uritani D, Fukumoto T, Matsumoto D, Shima M. Associations between toe grip strength and hallux valgus, toe curl ability, and foot arch height in Japanese adults aged 20 to 79 years: a cross sectional study. J Foot Ankle Res. 2015;8:18, 1 6. [32] Uritani D, Fukumoto T, Matsumoto D, Shima M. Reference values for toe grip strength among Japanese adults aged years: a cross sectional study. J Foot Ankle Res. 2014;7:28, 1 6. [33] Jung DY, Kim MH, Koh EK, Kwon OY, Cynn SH, Lee HW. A comparison in the muscle activity of the abductor hallucis and the medial longitudinal arch angle during toe curl and short foot exercises. Phys Ther Sport. 2011;12:30-5. [34] Hardy RH, Clapham JC R. Observations on hallux valgus. J Bone Joint Surg (Br). 1951;33:

23 Table 1: Baseline characteristics of participants (mean ± SD) Variables Treatment group Control P Value (n = 28) group(n = 28) Sex Female Female - Age (y) 45.7 ± ± Body mass index (in 25.6 ± ± kg/m 2 ) Hallux valgus angle 32.7 ± ± (º) First and second 14 ± 1 14 ± intermetatarsal angle (º) Visual analog scale 5.6 ± ± Hallux 46.1 ± ± interphalangeal joint scale (AOFAS) Ankle dorsiflexion 9.5 ± ± (º) Strength of hallux 50.4 ± ± plantar flexion (N) Strength of hallux 6.4 ± ± abduction (N) Toe grip strength (N) 65.2 ± ± SD = standard deviation; N = newton; AOFAS = American Orthopedic Foot and Ankle Society 23

24 Table 2: Comparison within the treatment group before treatment, after treatment, and at one-year follow-up (n=28) Variables Hallux valgus angle (º) First and second intermetatarsal angle (º) Visual analog scale Hallux interphalangeal joint scale (AOFAS) Ankle dorsiflexion (º) Strength of hallux plantar flexion (N) Strength of hallux abduction (N) Toe grip strength (N) Pre-study (mean ± SD) Post-study (mean ± SD) One year follow up (mean ± SD) P value 32.7 ± ± ± 2.1 < 0.001* 14 ± ± ± 0.9 < 0.001* 5.6 ± ± ± 1 < 0.001* 46.1 ± ± ± 2 < 0.001* 9.5 ± ± ± 2.1 < 0.001* 50.4 ± ± ± 2 < 0.001* 6.4 ± ± ± 1.3 < 0.001* 65.2 ± ± ± 5.2 < 0.001* SD = standard deviation; N = newton; AOFAS = American Orthopedic Foot and Ankle Society; * Statistically significant results. 24

25 Table 3: Control group comparison at beginning of the study, after 3 months, and after one-year follow-up (n=28) Variables Beginning of study (mean ± SD) After 3 months (mean ± SD) At one year (mean ± SD) P value Hallux valgus angle 31.9 ± ± ± (º) First and second 14 ± ± ± intermetatarsal angle (º) Visual analog scale 5.2 ± ± ± Hallux interphalangeal joint scale (AOFAS) 45 ± ± ± Ankle dorsiflexion 9 ± 1 9 ± 1 8 ± (º) Strength of hallux 49 ± 2 49 ± 2 47 ± plantar flexion (N) Strength of hallux 7 ± ± ± abduction (N) Toe grip strength (N) 66 ± 9 66 ± 9 64 ± SD = standard deviation; N = newton; AOFAS = American Orthopedic Foot and Ankle Society 25

26 Table 4. Comparison between both groups at one-year follow-up Variables Treatment group Control group P value (mean ± SD) (mean ± SD) Hallux valgus angle 25.8 ± ± 3.2 < 0.001* (º) First and second 12 ± ± 0.9 < 0.001* intermetatarsal angle (º) Visual analog scale 2.4 ± ± 1.3 < 0.001* Hallux 74.5 ± 2 43 ± 1.7 < 0.001* interphalangeal joint scale (AOFAS) Ankle dorsiflexion 13.2 ± ± 1 < 0.001* (º) Strength of hallux 62.9 ± 2 47 ± 2 < 0.001* plantar flexion (N) Strength of hallux 8.8 ± ± 0.8 < 0.001* abduction (N) Toe grip strength (N) 93.1 ± ± 9 < 0.001* SD = standard deviation; N = newton; AOFAS = American Orthopedic Foot and Ankle Society; * Statistically significant results. 26