Individuals with asymptomatic hallux valgus exhibit altered foot kinematics during gait regardless of their foot posture.

BACKGROUND: A flatfoot has been believed to be closely associated with the development of hallux valgus; however, the association is still controversial. Abnormal foot kinematics has been identified as a possible risk factor for the development of hallux valgus, but it remains unclear whether foot posture contributes to abnormal foot kinematics. This is the first study to investigate the differences in foot kinematics during gait between individuals with and without hallux valgus, while controlling for foot posture. METHODS: Twenty-five females with hallux valgus and 25 healthy females aged 18 to 22 were recruited. Foot posture was measured using normalized navicular height truncated and the leg-heel angle. Foot kinematic and kinetic data during gait were recorded by a three-dimensional motion capture system. To investigate the characteristics of foot kinematics in individuals with hallux valgus while controlling for foot posture, we used a propensity score matching method. The matching was obtained by using the 1:1 nearest-neighbor procedure and a caliper width of 0.2. FINDINGS: Twelve pairs were matched. Individuals with hallux valgus had significantly increased midfoot dorsiflexion from 56% to 80% during stance phase, rearfoot eversion from 53% to 71%, and forefoot abduction from 5% to 29% compared with control. INTERPRETATION: Individuals with hallux valgus have a flexible foot that cannot suppress the dynamic deformation of the rearfoot and midfoot during gait. To suppress the development of hallux valgus, interventions that aim to prevent dynamic deformations of the rearfoot and midfoot during gait may be necessary, regardless of their static foot posture.

Muscle synergy and kinematic synergy analyses during sit-to-stand motions in hallux valgus patients before and after treatment with Kinesio taping.

OBJECTIVES: To explore the impact of hallux valgus (HV) on lower limb neuromuscular control strategies during the sit-to-stand (STS) movement, and to evaluate the effects of Kinesio taping (KT) intervention on these control strategies in HV patients. METHODS: We included 14 young healthy controls (HY), 13 patients in the HV group (HV), and 11 patients in the HV group (HVI) who underwent a Kinesio taping (KT) intervention during sit-to-stand (STS) motions. We extracted muscle and kinematic synergies from EMG and motion capture data using non-negative matrix factorization (NNMF). In addition, we calculated the center of pressure (COP) and ground reaction forces (GRF) to assess balance performance. RESULTS: There were no significant differences in the numbers of muscle and kinematic synergies between groups. In the HV group, knee flexors and ankle plantar flexors were abnormally activated, and muscle synergy D was differentiated. Muscle synergy D was not differentiated in the HVI group. CONCLUSION: Abnormal activation of knee flexors and plantar flexors led to the differentiation of module D in HV patients, which can be used as an indicator of the progress of HV rehabilitation. KT intervention improved motor control mechanisms in HV patients.

Lower limb kinematic changes during gait after hallux valgus surgery: A prospective observational study.

BACKGROUND: Patients with hallux valgus are known to alter lower limb joint kinematics during gait. However, little information is available about gait changes following hallux valgus surgery. We aimed to longitudinally investigate lower limb kinematic changes at the mid and terminal stances of gait after hallux valgus surgery. METHODS: This prospective observational study included 11 female patients (17 feet), who underwent first metatarsal osteotomy. Gait analyses were performed preoperatively and 1- and 2-year postoperatively using a three-dimensional motion capture system. Toe-out angle, ankle, knee, and hip joint angles during gait were calculated from the recorded data. The spatiotemporal parameters and these angles at the mid and terminal stances of gait were statistically compared between preoperative and postoperative periods. FINDINGS: All spatiotemporal parameters remained unchanged postoperatively. The toe-out angle was significantly greater at 1- and 2-year postoperatively. The ankle pronation angle, the knee abduction angle, and the hip adduction angle at the mid and terminal stances of gait were smaller postoperatively compared to the preoperative. These angular changes showed a similar trend at 1 and 2 years postoperatively. However, the postoperative changes of the sagittal joint angles were relatively small. INTERPRETATION: Hallux valgus surgery can affect the toe-out angle and the lower limb coronal kinematics at the mid and terminal stances of gait in patients with hallux valgus. However, surgical correction of hallux valgus deformity did not directly improve the gait characteristics in patients with hallux valgus.

The vertical mobility of the first tarsometatarsal joint during demi-plié with forced turnout in ballet dancers.

The forced turnout has a perceived risk of development of hallux valgus (HV) in ballet dancers. We determined how the forced turnout affects the sagittal mobility of the first tarsometatarsal (TMT) joint, which is one of the pathogenic factors of HV development. Seventeen female ballet dancers (body mass index: 18.2 ± 1.8 kg/m2) were included and performed demi-plié in control, functional turnout, and forced turnout conditions. Ultrasound imaging synchronized with a three-dimensional motion analysis system was used for measuring the vertical locations of the first metatarsal and medial cuneiform (MC) to evaluate the first TMT joint mobility. Plantar displacement of MC and the first TMT joint mobility in the forced turnout were the greatest among the 3 conditions. Multiple regression analysis indicated that the greater extent of the forcing angle might increase the displacement of MC and the first TMT joint mobility. Evaluating the sagittal mobility of the first TMT joint in the forced turnout can assist in understanding the association between inappropriate techniques including the forced turnout and HV development in ballet dancers. Since the excessive mobility of the first TMT joint is a factor in HV development, the acquirement of adequate active turnout may have the potential to prevent HV development in ballet dancers.

Biomechanical evaluation of 3D-printed joint-type orthosis for hallux valgus.

BACKGROUND: Orthoses play an important role in the conservative treatment of hallux valgus (HV) with different therapeutic effects. In this study, a new HV orthosis was developed using three-dimensional (3D) printing technology. In addition, its kinematic effect was evaluated using motion analysis. METHODS: Seventeen participants with an HV angle of >20° were included in the study. The first metatarsophalangeal abduction angle before and after the orthosis was measured statically. Subsequently, dynamic first metatarsophalangeal abduction, dorsiflexion angle and ground reaction force with and without the orthosis were recorded and calculated during walking using a Vicon motion analysis system and force plates. The patients' comfort scales were determined after the motion analysis. RESULTS: The angular corrections of the orthosis in the first metatarsophalangeal abduction were 14.6° and 6.3° under static and dynamic conditions, respectively. Reduced hallux dorsiflexion was observed with the orthosis in the early stance phase. However, no significant changes in ground reaction forces were observed. CONCLUSION: The results of our study confirm the potential of the 3D-printed HV orthosis in the static and dynamic correction of deformities while ensuring patient comfort with minimal impact on hallux kinematics, suggesting the potential of our design for long-term use.

Effectiveness of footwear and foot orthoses in reducing medial metatarsophalangeal joint pressure in women with hallux valgus.

BACKGROUND: Hallux valgus is a common condition where the subluxation of the first metatarsophalangeal joint and lateral deviation of the hallux at the interphalangeal joint creates difficulty with footwear fit. Footwear and foot orthoses are commonly prescribed nonsurgical treatments for hallux valgus. RESEARCH QUESTION: Do extra-width footwear and foot orthoses influence peak pressure at the medial aspect of the metatarsophalangeal and interphalangeal joints in women with hallux valgus? METHODS: Community-dwelling women with symptomatic hallux valgus underwent gait testing when wearing their own shoes and when wearing extra-width footwear fitted with three-quarter length, arch-contouring prefabricated foot orthoses. Peak pressure (kPa) on the medial aspect of the metatarsophalangeal and medial interphalangeal joints and on the plantar surface of the foot (hallux, lesser toes, metatarsophalangeal joint 1, metatarsophalangeal joints 2-5, midfoot and heel) were measured using the novel pedar®-X system with the pedar® pad and pedar® insole, respectively (Novel, GmbH, Munich, Germany). Paired samples t-tests were used to calculate the differences between the two conditions, and the magnitude of observed differences was calculated using Cohen's d. RESULTS: We tested 28 participants (aged 44-80 years, mean 60.7, standard deviation 10.7). Compared to their own footwear, wearing the intervention footwear and orthoses was associated with a statistically significant decrease in pressure on the medial aspect of the metatarsophalangeal joint (58.3 ± 32.8 versus 42.6 ± 32.8, p=0.026, d=0.49), increased pressure under the midfoot (70.7 ± 25.7 versus 78.7 ± 23.6, p=0.029, d=0.33) and decreased pressure underneath the heel (137.3 ± 39.0 versus 121.3 ± 34.8, p=0.019, d=0.45). SIGNIFICANCE: The intervention footwear and orthoses significantly decreased peak pressure on the medial aspect of the first metatarsophalangeal joint but had no significant effect on the interphalangeal joint. Further studies are required to determine whether these changes are associated with improvements in symptoms associated with hallux valgus.

Radiologic and Clinical Outcomes of the Dovetailed Notch Scarf Osteotomy for Correcting the First Metatarsal Pronation in Moderate to Severe Hallux Valgus Deformity: A Comparative Study.

BACKGROUND: The traditional scarf osteotomy (TSO) has limited ability to correct the first metatarsal pronation. A novel modification that we refer to as a "dovetailed notch scarf osteotomy" (DNSO) has been developed to enhance the ability to correct coronal plane pronation. The study aimed to observe and compare TSO to DNSO in the treatment of moderate to severe hallux valgus deformity. METHODS: This retrospective study included 78 feet that had a TSO and 105 feet that had a DNSO. Minimum follow-up was 24 months. Weightbearing computed tomography (WBCT) and weightbearing anterior-posterior (AP) radiographs were taken preoperatively and at the last follow-up. We measured the intermetatarsal angle (IMA), hallux valgus angle, distal metatarsal articular surface angle on AP radiographs and first metatarsal coronal pronation angle (α angle), tibial sesamoid coronal grading, and first metatarsal length on WBCT. Clinical assessment was done using visual analog scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale, Foot and Ankle Ability Measure (FAAM), and the 36-Item Short Form Health Survey (SF-36). The occurrence of postoperative complications was also documented. RESULTS: The DNSO group exhibited a significantly higher correction amount of α angle and IMA (14.3 ± 9.9 and 10.3 ± 4.6 degrees) than the TSO group (8.6 ± 5.9 and 5.4 ± 5.9 degrees) during the final follow-up assessment (P < .05).The DNSO group (10.1 [8.0-12.0] degrees and 4.8 [3.9-5.6] degrees) demonstrated significantly smaller α angle and IMA compared with the TSO group (4.8 [3.9-5.6] degrees and 9.5 [7.5-11.5] degrees) at 24 months postsurgery (P < .05). The postoperative FAAM activities of daily living and SF-36 physical functioning scores were significantly higher in the DNSO group (97.2 ± 3.3 and 95.7 ± 4.4 points) compared with the TSO group (92.3 ± 3.3 and 87.7 ± 8.7 points) (P < .05). Additionally, hallux varus occurred in 1 case in the DNSO group, whereas 4 cases were observed in the TSO group. CONCLUSION: Two osteotomy methods can effectively correct moderate to severe hallux valgus deformity. Compared with the TSO, the DNSO has stronger correction ability. The most crucial aspect lies in its controllability when correcting first metatarsal pronation and addressing IMA. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Immediate effect of hallux valgus surgery on the biomechanical behavior of the first ray.

BACKGROUND: The surgical treatment of hallux valgus (HV) deformity has been the subject of countless publications but few focus on the altered windlass mechanism or analyze the biomechanical behavior immediately after surgery. METHODS: Patients treated for HV between January and March 2023 were included. The surgery consisted of a L-reverse first metatarsal osteotomy. To analyze the windlass mechanism we record two different measurements; the isolated first metatarsophalangeal joint (MTPJ) dorsiflexion angle (IDA) and dynamic plantarization of the first metatarsal head when performing first MTPJ dorsiflexion imprinting a mark on a modeling foam. RESULTS: A total of 30 patients diagnosed with symptomatic HV were included. In all patients, a change in the IDA angle was evident, being overall statistically significant. About modeling foam imprinted mark, all measurements, in all planes of space, had a clear tendency to increase, which turned out to be statistically significant (p < 0.001). CONCLUSIONS: An altered windlass mechanism may be successfully recovered immediately after hallux valgus deformity surgery. This could be evinced by an indirect measurement analyzing the imprint of the head of the first metatarsal in a modeling foam and the IDA. LEVELS OF EVIDENCE II: None.

First tarsometatarsal joint mobility in hallux valgus during gait: A synchronized ultrasound and three-dimensional motion capture analysis.

PURPOSE: To quantify the vertical translation between the first metatarsal and medial cuneiform during the stance phase of gait in young individuals with and without hallux valgus. DESIGN: This cross-sectional observational study included 34 young adults (male, n = 4; female, n = 30) who were divided into three groups according to the hallux valgus angle: control (< 20°, n = 13), mild hallux valgus (≥ 20° to < 30°, n = 12), and moderate hallux valgus (≥ 30°, n = 9). The mobility of the first tarsometatarsal joint was evaluated during the stance phase using B-mode ultrasound synchronized with a motion analysis system. RESULTS: The medial cuneiform shifted more plantar during the early phase in mild hallux valgus and during the middle and terminal phases in moderate hallux valgus than in control. The severity of the hallux valgus was correlated with a trend toward plantar shift of the medial cuneiform. The first metatarsal was located more dorsal than the medial cuneiform; however, there was no significant variation. No significant differences in the peak ankle plantarflexion angle and moment were noted between the groups. CONCLUSION: The hypermobility of the first tarsometatarsal joint, especially plantar displacement of the medial cuneiform in the sagittal plane, was found in young individuals with hallux valgus during the stance phase of gait, and the mobility increased with the severity of hallux valgus. Our findings suggest the significance of preventing hallux valgus deformity early in life.

Improvement of Valgus Deviation of the Lesser Toes of Moderate to Severe Hallux Valgus After Proximal Chevron Metatarsal Osteotomy and Akin Osteotomy.

BACKGROUND: This study examines the correction of lesser toe valgus deviation following proximal chevron metatarsal osteotomy (PCMO) and Akin osteotomy in moderate to severe hallux valgus patients, while identifying influencing factors. METHOD: Among 89 patients (116 feet), those with moderate to severe hallux valgus underwent PCMO and Akin osteotomy. Radiologic assessments included preoperative metatarsus adductus angle (MAA), hallux valgus angle (HVA), intermetatarsal angle (IMA), valgus angles of the second to fourth metatarsophalangeal joints, and hallux valgus recurrence. Assessments included visual analog scale (VAS) pain scores, American Orthopaedic Foot & Ankle Society (AOFAS) scores, and patient satisfaction over an average follow-up of 30.6 ± 21.2 (range, 12-99) months. RESULTS: The mean preoperative HVA of 34.4 degrees decreased to 8.7 degrees at final follow-up. The valgus angles of the second, third, and fourth toes improved by 37.1%, 27%, and 44.5%, respectively. In metatarsus adductus patients, lesser toe valgus angles were significantly higher both preoperatively and at final follow-up. Hallux valgus recurrence patients had higher preoperative and final follow-up IMA and valgus angles in the second and third toes. Nonrecurrence patients showed greater decreases in these angles. A larger HVA correction corresponded to a greater decrease in lesser toe valgus deviation. VAS and AOFAS scores improved significantly at the last follow-up. CONCLUSION: The study found a significant reduction in the valgus angle of the second, third, and fourth toes after PCMO and Akin osteotomy in moderate to severe hallux valgus cases, without additional surgeries on lesser toes. The lesser toe angular reductions were less pronounced in patients with metatarsus adductus or with hallux valgus recurrence. LEVEL OF EVIDENCE: Level IV, case series.

Protocol: a randomized parallel-group study of women after hallux valgus correction surgery to compare the effects of "core foot system" training vs. traditional rehabilitation methods.

Purpose: The aim of this study is to compare the effects of Core Foot System muscle training vs. traditional rehabilitation methods in female patients after a hallux valgus correction surgery. Methods: The project will involve 60 women who have undergone a Scarf osteotomy to correct the deformity. Participants will be divided into a control and experimental group. The experimental group will follow the Core Foot System protocol, whereas the control group will perform standard lower-limb exercises. Outcome measures will be collected twice: before the intervention and after eight weeks. Gait will be assessed using the Zebris FDM-2 platform, measuring ground reaction forces during walking. Results: The effects of the exercises on the cross-sectional area of the abductor hallucis muscle and the flexor digitorum brevis muscle will be measured. Foot architecture and arch height will be measured using a podoscope. In addition, the participants will complete the Short Form Health Survey and the American Orthopaedic Foot and Ankle Society questionnaires. Conclusions: The study is expected to provide evidence of the effectiveness of foot muscle training using the protocol. The findings may lead to an improved protocol of rehabilitation in patients after a correction surgery that may result in improved gait parameters and quality of daily life. In the future, an improved therapeutic method should make it possible to boost the effectiveness of physiotherapy in patients after a corrective surgery in the forefoot area. The study has been registered with clinicaltrials.org (NCT05210127; 13 January 2022).

The short-term effectiveness of Kinesiology Taping on foot biomechanics in patients with hallux valgus.

BACKGROUND: Hallux valgus, one of the most common foot disorders, contributes to the formation of pain and changes foot biomechanics. OBJECTIVE: To assess the impact of Kinesiology Taping (KT) on foot loading during gait in patients with hallux valgus. METHODS: Forty feet with hallux valgus were examined. Patients wore the KT for a month and the parameters of the foot during gait on a baropodometric platform were measured three times: before taping, immediately after application of taping and after one month's use. RESULTS: The taping had a statistically significant effect on dynamic foot measurements. The maximum and mean foot load (p< 0.001), foot surface (p< 0.001), ratio of forefoot to hindfoot load (p< 0.01) and the proportions of the lateral and medial foot loading (p< 0.05) all changed. During gait cycle, taping significantly increased the load and surface at the first metatarsal head (p< 0.001) while there was a decrease around the second to fifth (p< 0.001) metatarsal heads. CONCLUSIONS: Using KT to correct a hallux valgus is a procedure that has an impact on the dynamic parameters of the foot during gait. The use of this method could become an alternative to surgical treatment for those patients, who have any contraindication for surgery.

Differences in toe flexor strength and foot morphology between wheelchair dependent and ambulant older people in long-term care: a cross-sectional study.

BACKGROUND: Hallux valgus, lesser toe deformity, and muscle weakness of the toe flexors contribute to falls in older people. This study aimed to examine the differences in toe flexor strength and foot morphology in older people requiring long-term care due to changes in the way they mobilize in everyday life. METHODS: This study included 84 people aged ≥70 years without motor paralysis who underwent rehabilitation. They were divided into those who could mobilize without a wheelchair (walking group, n = 54) and those who used a wheelchair to mobilize (wheelchair group, n = 30). The presence or absence of diseases was confirmed, and hand grip strength, toe flexor strength, and foot morphology using the foot printer were measured. The presence of diseases, hand grip strength, toe flexor strength, and foot morphology were compared between the two groups. Multiple logistic analysis was performed with wheelchair dependence as the dichotomous outcome variable, and the percentages of each strength measure observed in the wheelchair group to the average hand grip and toe flexor strength measures in the walking group were compared. RESULTS: No significant between-group difference in foot morphology was found. The factors related to the differences in ways of ambulating in daily life were history of fracture, heart disease, and toe flexor strength. After comparing the muscle strength of the wheelchair group with the mean values of the walking group, we found that the toe flexor strength was significantly lower than the hand grip strength. CONCLUSIONS: Older people who used a wheelchair to mobilize have significantly less toe flexor strength than those who do not despite no significant difference in foot morphology. Use of a wheelchair is associated with a reduction in toe flexor strength.

The effect of hallux valgus open and percutaneous surgery on AOFAS scale: a systematic review and meta-analysis.

PURPOSE: To estimate the comparative effect of open and percutaneous hallux valgus (HV) surgery on patients' quality of life (QoL) using the American Orthopedic Foot and Ankle Society (AOFAS) scale including total score and individual domains (pain, function, and alignment). METHODS: MEDLINE, EMBASE, Cochrane Library, and Web of Science databases were systematically searched from inception to March 2020 for studies on the effect of HV surgery on patients' QoL using the AOFAS score. A standardized mean difference score was calculated on the total AOFAS score and on each AOFAS domain (pain, function, and alignment) using Cohen's d index. RESULTS: Considering the 53 published studies included, the pooled effect size (ES) estimates for the AOFAS total score were 3.69 (95% CI 3.37-4.01; I2 = 95.5%) for open surgery and 3.40 (95% CI 2.99-3.80, I2 = 88.2%) for percutaneous surgery. The total pooled ES estimate was 3.61 (95% CI 3.35-3.87, I2 = 94.5%). Considering the pain domain, the pooled ES estimates were 2.21 (95% CI 1.98-2.43, I2 = 64%) for open surgery and 2.52 (95% CI 1.83-3.20, I2 = 92.6%) for percutaneous surgery. For the function domain, the pooled ES estimates were 1.37 (95% CI 0.93-1.81, I2 = 91%) for open surgery and 2.28 (95% CI 1.10-3.47, I2 = 96.8%) for percutaneous surgery. Finally, the pooled ES estimates for the alignment domain were 3.99 (95% CI 3.51-4.47, I2 = 85.7%) for open surgery and 2.66 (95% CI 2.23-3.09, I2 = 78.5%) for percutaneous surgery. CONCLUSION: Our data support that HV surgery increases the total AOFAS score as well as the AOFAS scores by domain (pain, function, and alignment). Furthermore, our data show that HV surgery increases patients' QoL, after both open and percutaneous surgery, without differences between them.

Postural stability impairment in patients with bilateral hallux valgus: A case-control study using a stabilometer.

BACKGROUND: Hallux valgus (HV) is an important risk factor for falls (in older people); however, the detailed relationship is less understood. We aimed to evaluate postural stability in bilateral HV patients. METHODS: Two groups of 20 female patients-an HV group and a C (i.e., non-HV) group-participated in this study. Evaluations were made using the Timed Up and Go (TUG) test, the Berg Balance Scale (BBS), the Falls Efficacy Scale (FES), track length (LNG), velocity (VEL), enveloped area (ENV), and root mean square area (RMS). RESULTS: TUG and FES scores were significantly higher and BBS scores were lower in the HV group than in the C group. LNG was significantly longer, VEL was higher, and ENV and RMS were wider in the HV group than in the C group. CONCLUSIONS: The HV group exhibited impaired walking mobility, balance, and postural stability.

Scarf osteotomy for hallux valgus deformity: Radiological outcome, metatarsal length and early complications in 118 feet.

BACKGROUND: Scarf osteotomy has been widely used to restore axial orientation of the first ray in the treatment of hallux valgus deformity. The aim of the study was to present our radiological outcomes of bunion reconstruction, identify surgical complications in early follow-up, and assess to what extent a shortening of the first metatarsal is present after surgery as a possible cause of postoperative metatarsalgia. METHODS: We enrolled 106 patients (118 feet) and assessed patients' pre- and postoperative measurements of hallux valgus and intermetatarsal angles on weightbearing X-ray images. Three different methods of measuring metatarsal length were compared and early postoperative complications noted. RESULTS: Hallux valgus angle decreased significantly by an average of 18.7 degrees and the intermetatarsal angle by 7.8 degrees. Using three methods of measuring metatarsal length, all showed significant shortening of the first metatarsal. Mean relative lengthening of the second metatarsal averaged 0.45mm. The Coughlin method showed the highest interrater reliability (ICC=0.96). CONCLUSIONS: Significant reduction of the hallux valgus angle and intermetatarsal angle was demonstrated with a low complication rate. There was significant shortening of the first metatarsal. The Coughlin method clearly demonstrated an excellent interrater reliability. LEVEL OF EVIDENCE: Level IV.

Ground reaction force complexity in hallux valgus.

BACKGROUND: Investigating the complexity of movement systems can be insightful in clinical decision making. The study conducted to evaluate whether complexity of ground reaction force is affected by hallux valgus grades and footwear or foot side conditions. METHODS: A sample of 120 females including 30 participants in each group of healthy and mild, moderate, and severe hallux valgus were recruited in this case-control study. Hallux valgus grades were assessed using Manchester scale. Ground reaction force were measured in bare foot and shod conditions for both feet and weighted permutation entropy was used to calculate the complexity. Nonparametric tests were employed for statistical inference. FINDINGS: The first important result was that hallux valgus caused loss of complexity of ground reaction force with a medium to large effect size. However, we did not find any difference between three grades of hallux valgus entropy. The second finding was that entropy of healthy group decreased from barefoot to shod condition with a large effect size and the third finding was that ground reaction force entropy were similar in both feet. INTERPRETATION: The findings are aligned with the theory that loss of complexity appears when the biological systems become functionally impaired. As soon as hallux valgus initiates, all potential risks related to the reduction of complexity appear. So, we suggest to administer conservative treatments in the early stages of hallux valgus. The study outcomes can be used for evaluation of foot function, classification of the foot types, or footwear selection.

Foot structural factors and ground reaction force in hallux valgus grades.

BACKGROUND: Little attention has been paid to foot structural factors and ground reaction force in hallux valgus. Investigating the structural factors in detail and determining their biomechanical effects can help to better manage hallux valgus. METHODS: In this case-control study, 120 females, 90 hallux valgus and 30 healthy, were recruited. Hallux valgus grades (mild, moderate, severe), first metatarsal mobility, foot pronation, hallux rotation, and pain were assessed by clinical tests. Ground reaction forces were measured in barefoot and shod conditions for both feet and analyzed using mixed within-between MANOVA. The association between structural factors and pain with force was analyzed using Spearman correlation coefficient. RESULTS: The frequency of foot structural factors and pain severity were reported in hallux valgus grades. A significant difference was seen in the force values between groups (P<0.001). Bonferroni post hoc test indicated that the mean of the first peak for the severe group was significantly higher than the mild group (P=0.013) and the mean of second peak for the moderate group was higher than that of the healthy group (P=0.009). The force values were affected by wearing shoe (P<0.001) but not by foot side (P=0.086). There was a medium, positive correlation between the hallux rotation and force in the moderate group (r=0.39, P=0.03) and also between the pronation and force in the severe group (r=0.36, P=0.04). CONCLUSION: Foot structural factors, pain, and force were different in each hallux valgus grads. Similar force in both feet, and increased force by wearing shoe were seen. The relationship between the pronation and hallux rotation with force revealed the importance of these factors from the biomechanical viewpoint.

The functional capacity and morphological characteristics of the intrinsic foot muscles in subjects with Hallux Valgus deformity: A systematic review.

BACKGROUND: The intrinsic foot muscles are vital for maintaining normal foot function. This study was conducted to systematically review the literature on the functional capacity and morphological characteristics of the intrinsic foot muscles in subjects with Hallux Valgus (HV) deformity. METHODS: A search was carried out in all available electronic databases, including Pub Med, Scopus, Embase and Web of Science, for identifying any relevant studies published from 1990 to October 2018. RESULTS: Three studies had investigated intrinsic foot muscle size using ultrasound imaging; two had reported electromyography parameters and four had measured the muscle force capacity. The results of the present review suggested that the functional capacity and morphological characteristics of intrinsic foot muscles are different in subjects with HV compared to those without this deformity. CONCLUSION: This review found scientific evidence on muscle performance impairment in the abductor hallucis and flexor hallucis brevis in subjects with HV deformity.

First ray alignment in Lapidus arthrodesis - Effect on plantar pressure distribution and the occurrence of metatarsalgia.

BACKGROUND: Lapidus arthrodesis is an established treatment option for severe hallux valgus deformity especially in patients suffering from instability of the first tarsometatarsal joint. Surgery related metatarsalgia is known to be associated with persistent elevation of the first ray after realignment surgery. Nevertheless, detailed information on ideal positioning of the first ray in Lapidus surgery is missing so far. This study was designed to determine any correlations between radiographic and pedobarographic outcome following the Lapidus procedure with regard to clinical outcome and the occurrence of metatarsalgia. METHODS: Thirty feet (28 patients) after Lapidus surgery were available for follow-up at 42.5±21.0 months. All subjects had radiographic and pedobarographic evaluation of the operated foot and patient satisfaction was recorded using questionnaires. RESULTS: Metatarsalgia was associated with a poorer outcome in FADI and AOFAS scores (p<0.005). A lateral shift of plantar pressure distribution to the third metatarsal head in these cases could be observed. Although Lapidus surgery resulted in significant shortening of the first metatarsal, no correlation to the occurrence of metatarsalgia was detectable. Likewise, axial plane malalignment showed no influence, whereas elevation of the first ray was highly correlated to surgery related metatarsalgia (p=0.007). Subjects suffering from metatarsalgia had a higher BMI (body mass index), but its effect on metatarsalgia turned out not to be significant (p=0.090). CONCLUSION: In Lapidus surgery realignment of the first metatarsal in the sagittal plane seems to be decisive for good clinical outcome. Failing to plantarflex the arthrodesis resulted in a lateral shift of plantar loading with overload of the lesser metatarsals and the occurrence of metatarsalgia.