Potential for foot dysfunction and plantar fasciitis according to the shape of the foot arch in young adults

Flatfoot arch correction with generic 3D-printed orthoses at different body weight percentages

BACKGROUND

Flatfoot can be associated with foot pathologies and treated conservatively with foot orthoses to correct arch collapse and alleviate painful symptoms. Recently, 3D printing has become more popular and is widely used for medical device manufacturing, such as orthoses. This study aims at quantifying the effect of generic 3D-printed foot orthoses on flatfoot arch correction under different static loading conditions.

METHODS

Participants with normal and flatfeet were recruited for this cross-sectional study. Clinical evaluation included arch height, foot posture index, and Beighton flexibility score. Surface imaging was performed in different loading conditions: 1) 0% when sitting, 2) 50% when standing on both feet, and 3) 125% when standing on one foot with a weighted vest. For flatfoot participants, three configurations were tested: without an orthosis, with a soft generic 3D printed orthosis, and with a rigid 3D printed orthosis. Arch heights and medial arch angles were calculated and compared for the different loading conditions and with or without orthoses. The differences between groups, with and without orthoses, were analyzed with Kruskal-Wallis tests, and a p < 0.05 was considered significant.

RESULTS

A total of 10 normal feet and 10 flatfeet were analyzed. The 3D printed orthosis significantly increased arch height in all loading conditions, compared to flatfeet without orthosis. Wearing an orthosis reduced the medial arch angle, although not significantly. Our technique was found to have good to excellent intra and interclass correlation coefficients.

CONCLUSIONS

Generic 3D printed orthoses corrected arch collapse in static loading conditions, including 125% body weight to simulate functional tasks like walking. Our protocol was found to be reliable and easier to implement in a clinical setting compared to previously reported methods.

LEVEL OF EVIDENCE

II.

Impact of plantar fasciitis on postural control and walking in young middle-aged adults

PURPOSE

To assess if plantar fasciitis has an impact on postural control and walking pattern from gait analysis across different experimental conditions.

METHODS

Thirty participants (n = 15 with plantar fasciitis) performed 5 different balance tasks on a force platform, and the center of pressure (COP) was computed for postural control analysis. Participants were also asked to walk at 3 different speeds on a gait analysis system to compute the spatial-temporal parameters. Clinical foot measurements (pain, mobility) were also collected through all participants.

RESULTS

Clinical foot measurements showed no significant difference between the two groups; except for pain palpation in plantar fasciitis group. Significant differences were observed between the two groups for COP area displacement sway (p < 0.01; d = 0.08) and velocity (p = 0.022; d = 0.04), where the fasciitis group reported poorer postural control than control mainly during more challenging balance tasks (semi-tandem, unipodal). Plantar fasciitis group reported a decrease of gait velocity (p < 0.01; d = 0.12), step length (p < 0.01; d = 0.16) and step width (p < 0.01; d = 0.18) when compared to the healthy group across walking speed tests.

CONCLUSIONS

Individuals with plantar fasciitis report poor postural control and changes in walking pattern across three speeds performance.

Determining the knee joint laxity between the pronated foot and normal arched foot in adult participants

AIM OF THE STUDY

Foot pronation is often associated with increased internal rotation of the lower limb, predisposing the knee joint to greater stress. However, the impact of the pronated foot on knee joint laxity has not been well understood. The study aims to find out the effect of the pronated foot on knee joint laxity.

METHODS

Forty adult participants were recruited for the study: 20 with asymptomatic pronated foot and 20 control subjects with the normal arched foot. Foot assessments were performed by navicular drop test and rearfoot angle measurements. Knee joint laxity was measured by a KT 1000 arthrometer of the dominant leg. An independent t-test was performed to detect the differences between both groups.

RESULTS

Both groups were similar in age, BMI and physical activity level. The findings showed no significant differences between the pronated foot and control group in the knee joint laxity (P = 0.645).

CONCLUSIONS

There were no significant differences in anterior knee displacement between the pronated foot and normal arch foot. The study showed that pronated foot might not be responsible for ACL injuries during the age of twenties and cofounding factors. Further research is needed to investigate older subjects with the pronated foot.

Age, Body Mass Index, and Spur Size Associated with Patients’ Symptoms in Plantar Fasciitis

Background

Plantar fasciitis is a common cause of heel pain affecting 10% of the general population. This study aimed to investigate the specific symptoms in patients with plantar fasciitis using the Foot and Ankle Outcome Score (FAOS) questionnaire and their relationship with demographic and radiographic factors.

Methods

We retrospectively analyzed 73 consecutive patients (mean age, 53.8 ± 10.0 years; 20 men and 53 women) with plantar fasciitis who had visited our foot and ankle clinic and undergone weight-bearing foot X-ray examinations. Their demographic data, anteroposterior and lateral talo-first metatarsal angles, intermetatarsal and hallux valgus angles, and responses to the FAOS questionnaire were recorded.

Results

The quality-of-life subscale showed the lowest score of all FAOS subscales. Age was significantly correlated with quality of life (r = 0.297, p = 0.011), and body mass index was correlated with the function in sports and recreational activities (r = –0.251, p = 0.032). Age and body mass index were statistically significantly correlated with calcaneal spur size (r = 0.274, p = 0.027 and r = 0.324, p = 0.008, respectively). The calcaneal spur size was significantly correlated with pain (r = –0.348, p = 0.004), function in daily living (r = –0.410, p = 0.001), and function in sports and recreational activities (r = –0.439, p < 0.001).

Conclusions

Demographic factors were associated with specific symptoms in patients with plantar fasciitis. Calcaneal spur size was the only radiographic parameter correlated with symptoms. These findings help communicate with patients, set appropriate treatment goals, and evaluate treatment effectiveness.

A three-week intervention emphasized diagonal eccentric contraction on balance and joint position sense and ankle strength in subjects with ankle instability: A randomized controlled trial

BACKGROUND

Problems related to ankle instability, decreased proprioceptive sensation, altered static and dynamic balance abilities are suggested as major representative factors that contribute to the recurrence of ankle sprains.

OBJECTIVE

To assess the effect of a three-week intervention (intervention emphasizing diagonal eccentric contraction (IEDEC) and intervention of general exercise (IGE)) on static and dynamic balance abilities, ankle strength and joint position sense at pre- and post-intervention, and at two- and three-week post-intervention.

METHODS

Twenty-five participants with ankle instability, including a history of ankle sprain and recurrent episodes of giving way, were enrolled in the study. They were randomly classified into the IEDEC group (n= 12) and the IGE group (n= 13). Dynamic balance was examined using the Y Balance Test, four-way ankle strength was measured, and the static balance was evaluated using the total displacement of the center of pressure (COP). To identify the joint position error, eversion and inversion of the ankle angle were measured.

RESULTS

The results revealed significant increases in ankle dynamic stability and strength at two and three weeks post-intervention (p< 0.05). Similarly, the total displacement of the COP differed significantly over time, with a higher COP during the initial measurement than at two and three weeks intervention (p< 0.05) General balance training with IEDEC can improve position sense during ankle inversion (p< 0.05).

CONCLUSION

General balance training with IEDEC improved the position sense of the inversion. Combined therapeutic intervention, such as with the manual technique, could be a beneficial approach to maximize the treatment effects.

Influence of arch support heights on the internal foot mechanics of flatfoot during walking: A muscle-driven finite element analysis

BACKGROUND

Different arch support heights of the customized foot orthosis could produce different effects on the internal biomechanics of the foot. However, quantitative evidence is scarce. Therefore, we aimed to investigate and quantify the influence of arch support heights on the internal foot biomechanics during walking stance.

METHODS

We reconstructed a foot finite element model from a volunteer with flexible flatfoot. The model enabled a three-dimensional representation of the plantar fascia and its interactions with surrounding osteotendinous structures. The volunteer walked in foot orthosis with different arch heights (low, neutral, and high). Muscle forces during gaits were calculated by a multibody model and used to drive a foot finite element model. The foot contact pressures and plantar fascia strains in different regions were compared among the insole conditions at the first and second vertical ground reaction force (VGRF) peak and VGRF valley instants.

RESULTS

The results indicated that peak foot pressures decreased in balanced standing and second VGRF as the arch support height increased. However, peak midfoot pressures increased during all simulated instants. Meanwhile, high arch support decreased the plantar fascia loading by 5%-15.4% in proximal regions but increased in the middle and distal regions.

CONCLUSION

Although arch support could generally decrease the plantar foot pressure and plantar fascia loading, the excessive arch height may induce high midfoot pressure and loadings at the central portion of the plantar fascia. The consideration of fascia-soft tissue interaction in modeling could improve the prediction of plantar fascia strains towards design optimization for orthoses.

Midarch Foot Pain: Entrapment Neuropathy of the Distal Medial Plantar Nerve and Its Branches

Medial forefoot pain, or midarch pain, is usually attributed to plantar fasciitis. The authors present their findings of a previously unreported nerve entrapment of the medial proper plantar digital nerve (MPPDN). Ten fresh-frozen cadaveric specimens were analyzed for anatomical variance in the nerve distribution of the MPPDN. In addition, clinical results from a retrospective review of nine patients who underwent surgical nerve decompression of the MPPDN are presented. Significant anatomical variance was found for the MPPDN in the cadaveric dissection of 10 fresh-frozen specimens. Nine patients with a clinical diagnosis of entrapment of the MPPDN all obtained excellent pain relief with surgical external neurolysis. Only one complication occurred: a hypertrophic scar formation that was successfully treated with intralesional steroid injections. The authors believe that this MPPDN entrapment is often overlooked or misdiagnosed as plantar fasciitis. Surgical peripheral nerve decompression of this nerve can provide positive outcomes for patients suffering from midarch foot pain caused by this pain generator.

Three-Dimensional Ankle Exercise with Combined Isotonic Technique for an Obese Subject with Plantar Fasciitis: A Case Study

Background and objectives: Obese people have many foot-related disorders and plantar fasciitis (PF) is the most common disorder among them. However, research on the role of therapeutic exercises in PF is lacking and there is no evidence to suggest its benefits. As such, a further insight into therapeutic exercises is needed within this group. This case study investigated the effect of three-dimensional (3D) ankle exercises using a combined isotonic (CI) technique on function and balance in an obese subject with PF. Material and methods: The subject in this study was a 28-year-old obese woman who was diagnosed with PF by an orthopedic surgeon. A 3D ankle exercise program was commenced three times a week for 15 min over 4 weeks. The evaluations were conducted at five intervals: pre-test, and at 1, 2, 3 and 4 weeks from the initiation of the intervention. The tests were conducted in the following order: the patient-specific functional scale test (PSFS), an ultrasound of the plantar fascia, the heel pressure and balance test, the pressure pain threshold (PPT), and the 4-way ankle strength test. Results: The mean score of the PSFS test reduced by 70.55% after 4 weeks of the intervention. The thickness of the plantar fascia and heel pressure measured during single-leg standing decreased by 6.67% and 10.37%, respectively, after 4 weeks of the intervention. The anteroposterior and medial-lateral balance ability showed improvements of 8.29% and 8.61%, respectively, after 4 weeks of the intervention. The PPT improved by 38.01% after 4 weeks of the intervention. In the 4-way ankle strength test, dorsiflexion, plantar flexion, inversion, and eversion increased by 14.46%, 9.63%, 4.3% and 13.25%, respectively, after 4 weeks of the intervention. Conclusion: 3D ankle exercises utilizing the CI technique were shown to be effective in improving foot function, pressure pain, and muscle strength in dorsiflexion and inversion in an obese patient with PF.

Natural Value of Böhler's Angle in Normal Chinese Population

Objective

To determine the value of Böhler's angle (BA) in a group of Chinese people, analyze possible factors that influence it, and compare BA with that in previous literature.

Methods

A total of 143 cases, aged from 4 to 79 years, were enrolled in the study, including 64 males and 79 females (79 left feet and 64 right feet). Radiographs were independently measured by six observers. Age, sex, body side, subtalar joint congruity (STJC), and X‐beam obliquity (TT) were recorded. The database was assessed based on intraobserver agreement, data distribution, the randomness of case selection, and the ratio equality of binomial variables. Then, the normal value of BA was established, as well as the correlation between BA and other parameters.

Results

In the present study, the interobserver reliability of BA, STJC, and TT was excellent. The BA data revealed a normal distribution, and the randomness of case selection was verified for age, sex, and body side. The ratio of sex and body side was equal. Homogeneity of variance was observed when comparing the value of BA between different groups. The value of BA was 31.6° ± 5.19° (range, 20.08°–47.19°), which was not related to age, sex, body side, and minor X‐ray beam obliquity. BA application was not suitable for individuals younger than 10 years. The mean value of BA in this study was not identical with those in previous reports. This demonstrated that BA varies for different races.

Conclusion

For Chinese people, 30° to 33° is recommended as the target value of BA for calcaneal fracture reduction, except in children under 10 years of age.

Comparison of Foot Structure, Function, Plantar Pressure and Balance Ability According to the Body Mass Index of Young Adults

Objectives

This study compared foot arch height, plantar fascia thickness, a range of motion assessments of the ankle joint, strength of the ankle joint, plantar pressure, and balance between obese and normal weight young adults.

Methods

Fifty-two participants were required for the present study design to achieve 80% power, 0.8 effect size (η2), and an alpha level of 0.05. The participants were categorized to normal weight or obese groups based on BMI (≤ 24 kg/m² and ≥ 25 kg/m², respectively). The foot and ankle disability index and Sport survey were completed by the participants before the measurements. Foot arch height was measured using the navicular drop test, and plantar fascia thickness was measured using ultrasound. Plantar pressure and balance tests were also conducted, followed by ankle joint range of motion and strength tests.

Results

Foot arch height and plantar fascia thickness was significantly higher in the obese group compared with the normal weight group (p < 0.01). There were significant differences in eversion of ankle strength, plantar pressure in the big toe and heel and anterior-posterior balance between normal and obese weight groups (p < 0.05).

Conclusion

Obese young adults had more abnormalities in the medial longitudinal arch, plantar fascia, and plantar pressure as well as weakened ankle eversion strength and balance problems compared with the normal weight group.

Anatomical variations of the plantar fascia's origin with respect to age and sex-an MRI based study

The plantar fascia (PF) plays a significant role in ankle movement and anatomical variations of this structure may significantly alter the biomechanical properties of the foot and lower extremity. The aim of this study was to evaluate the changes of the PF's origin point on the calcaneus (CB), and whether these changes are dependent on age and sex. Two independent observers evaluated two hundred and two foot and ankle MRIs and the following measurements was performed: (A) horizontal length of the AT insertion into the posterior aspect of the CB, (B) horizontal length of the CB and (C) horizontal distance from the most anterior point of the CB to the most posterior part of the PF. Statistical analysis was performed with the results obtained to evaluate both sex and age differences. Based on our results, we observed that: (1) changes of the PF's origin point on the CB is independent of age and sex and (2) the continuity between the PF and AT decreases during aging as a result from changes in the AT's insertion point into the CB. This study concludes that the PF's origin point does not change with respect to age or sex, but the continuity between the PF and AT decreases during aging. Knowledge regarding the biomechanical influences caused by changes in the relationship between the AT and PF may be important in terms of treatment and prophylaxis of both PF and AT pathologies. Clin. Anat. 32:597-602, 2019. © 2019 Wiley Periodicals, Inc.