Clinical foot measurements as a proxy for plantar pressure testing in people with diabetes

The relationship between Foot Posture Index and plantar pressure in a community-dwelling adult population with Type 2 diabetes

AIMS

To investigate the contribution of foot type to plantar pressures in a community-dwelling adult population with type 2 diabetes.

METHODS

Foot Posture Index-6 (FPI-6) as a measure of foot type, barefoot plantar pressure (peak pressures and pressure-time integrals), presence of forefoot deformities, peripheral neuropathy, ankle and first metatarsophalangeal joint (MTPJ) dorsiflexion range of motion (ROM), and demographic variables were measured. Standard multiple regression models were used to investigate the independent contribution of FPI-6 on plantar pressure variables at the hallux, forefoot, and rearfoot.

RESULTS

122 adults (mean age 70.9 ± 9.3, n = 58 female) with type 2 diabetes were recruited. A lower (more supinated) FPI-6 significantly contributed to an increased forefoot pressure-time integral (β = -0.285, p = 0.04). FPI-6 was not a statistically significant independent predictor of peak pressure at the hallux, forefoot or rearfoot.

CONCLUSIONS

When screening for at-risk sites of elevated plantar pressure in adults with type 2 diabetes, clinicians should consider performing the FPI-6 along with other clinical measures that have been shown to be associated with increased plantar pressures including first MTPJ dorsiflexion ROM, and presence of digital deformities. Evidence-based treatments to offload these areas should then be considered.

Validity, reliability, and bias between instrumented pedals and loadsol insoles during stationary cycling

The purpose of this study was to evaluate the validity and reliability of the loadsol in measuring pedal reaction force (PRF) during stationary cycling as well as lower limb symmetry. Ten healthy participants performed bouts of cycling at 1kg, 2kg, and 3kg workloads (conditions) on a cycle ergometer. The ergometer was fitted with instrumented pedals and participants wore loadsol plantar pressure insoles. A 3 x 2 (Condition x Sensor Type) ANOVA was used to examine the differences in measured peak PRF, impulse, and symmetry indices. Root mean square error, intraclass correlation coefficients, and Passing-Bablok regressions were used to further assess reliability and validity. The loadsol demonstrated poor (< 0.5) to excellent (> 0.9) agreement as measured by intraclass correlation coefficients for impulse and peak PRF. Passing-Bablok regression revealed a systematic bias only when assessing all workloads together for impulse with no bias present when looking at individual workloads. The loadsol provides a consistent ability to measure PRF and symmetry when compared to a gold standard of instrumented pedals but exhibits an absolute underestimation of peak PRF. This study provides support that the loadsol can identify and track symmetry differences in stationary cycling which means there is possible usage for clinical scenarios and interventions in populations with bilateral asymmetries such as individuals with knee replacements, limb length discrepancies, diabetes, or neurological conditions. Further investigation of bias should be conducted in longer cycling sessions to ensure that the loadsol system is able to maintain accuracy during extended use.

Potential predictive effect of mechanical properties of the plantar skin and superficial soft tissue, and vibration perception on plantar loading during gait in individuals with diabetes

BACKGROUND

This exploratory study aimed to investigate the extent to which mechanical properties of the plantar skin and superficial soft tissue (hardness, stiffness, and thickness) and vibration perception thresholds (VPTs) predict plantar pressure loading during gait in people with diabetes compared to healthy controls.

METHODS

Mechanical properties, VPTs, and plantar loadings during gait at the heel and first metatarsal head (MTH) of 20 subjects with diabetes, 13 with DPN, and 33 healthy controls were acquired. Multiple regression analyses were used to predict plantar pressure peaks and pressure-time integrals at both locations based on the mechanical properties of the skin and superficial soft tissues and VPTs.

RESULTS

In the diabetes group at the MTH, skin hardness associated with 30-Hz (R2 = 0.343) and 200-Hz (R2 = 0.314) VPTs predicted peak pressure at the forefoot. In the controls at the heel, peak pressure was predicted by the skin thickness, hardness, and stiffness associated with 30-Hz (R2 = 0.269, 0.268, and 0.267, respectively) and 200-Hz (R2 = 0.214, 0.247, and 0.265, respectively) VPTs.

CONCLUSION

The forefoot loading of people with diabetes can be predicted by the hardness of the skin when combined with loss of vibration perception at low (30-Hz) and high (200-Hz) frequencies. Further data from larger sample sizes are needed to confirm the current findings.

Bipedal Static Supination and Dynamic Forefoot Loading Characteristics in Taiwanese College Badminton Players: A Cross-Sectional Study

CONTEXT

Badminton is a unilateral sport that involves repetitive jumping, lunging and quick changes of direction with the lower limb, thus, plantar pressure profiles and foot postural profiles are critical to maintaining balance and coordination.

OBJECTIVE

The purpose of this study was to explore the characteristics of static and dynamic plantar pressure profiles with rearfoot posture in elite and recreational badminton players as well as assess the transitional changes of plantar loads between static and dynamic states.

METHODS

A cross-sectional survey was conducted among 65 college-level elite male badminton players (mean age: 20.2 ± 1.2 years; mean height: 177.4 ± 4.6 cm; mean weight: 72.6 ± 4.6 kg) and 68 recreational badminton players of the same gender (mean age: 19.9 ± 0.8 years; mean height: 170.3 ± 3.9 cm; mean weight: 67.7 ± 3.2 kg). The JC Mat was used to evaluate the arch index (AI), plantar pressure distribution (PPD), centers of gravity, and the characteristics of the footprint. Static foot posture was determined by examining the rearfoot alignment.

RESULTS

Both groups' AI fell within the normal range. The static plantar loads of the elite group were distributed at the bipedal lateral part of longitudinal arches and heels (p < 0.01), while the right foot experienced higher centers of gravity (p < 0.05). The elite group's static rearfoot postural alignment exhibited a higher degree of rearfoot varus than the recreational group (p < 0.05). In addition, the elite group's dynamic plantar loads were mainly exerted at the medial and lateral metatarsals of both feet (p < 0.05). During the transition state, the recreational group's plantar loads were mainly shifted to the bipedal lateral part of metatarsals and heels (p < 0.05), whereas the elite group's bipedal lateral longitudinal arches as well as the medial and lateral heels experienced a reduction in plantar loads (p < 0.01).

CONCLUSION

For elite badminton players, the findings revealed a possible connection among the static supinated foot, centers of gravity tending towards the right foot, and increased forefoot plantar loads in the dynamic state. The finding merits further exploration of the possible links between transitional changes in plantar pressure distribution in both states and related foot injuries resulting from intense competition and regular training in badminton.

Could an Internet-Based Foot-Ankle Therapeutic Exercise Program Modify Clinical Outcomes and Gait Biomechanics in People with Diabetic Neuropathy? A Clinical Proof-of-Concept Study

Previous studies have shown the efficacy of foot-ankle exercises in people with diabetic peripheral neuropathy (DPN), but the quality of evidence is still low. This proof-of-concept study pursues preliminary evidence for potential clinical and gait biomechanical benefits from an internet-based foot-ankle therapeutic exercise program for people with DPN. We randomized 30 individuals with DPN (IWGDF risk category 1 or 2) into either the control group (CG) receiving the usual care or the intervention group (IG) receiving the usual care plus an internet-based foot-ankle exercise program, fully guided by the Sistema de Orientação ao Pé Diabético (SOPeD; translation: Diabetic Foot Guidance System) three times per week for 12 weeks. We assessed face-to-face clinical and biomechanical outcomes at baseline, 12 weeks, and 24 weeks (follow up). Participants had good adherence to the proposed intervention and it led to only mild adverse events. The IG showed improvements in the ankle and first metatarsophalangeal joint motion after 12 and 24 weeks, changed forefoot load absorption during foot rollover during gait after 24 weeks, reduced foot pain after 12 weeks, and improved foot function after 24 weeks. A 12-week internet-based foot-ankle exercise program using the SOPeD software (version 1.0) has the potential to reduce foot pain, improve foot function, and modify some important foot-ankle kinematic outcomes in people with DPN.

Traceable Features of Static Plantar Pressure Characteristics and Foot Postures in College Students with Hemiplegic Cerebral Palsy

Patients with cerebral palsy (CP) are characterized by disturbances of mobility with postural and foot deformities. Subsequent development of CP may lead to changes in plantar loading. This study examined the characteristics of foot types and relative loads associated with centers of gravity and foot posture in college students with left and right hemiplegic CP, as well as these differences between unaffected and hemiplegic limbs. A cross-sectional study of 45 hemiplegic college students with mild CP and 62 healthy students was conducted. Static plantar pressure was measured with a JC Mat. CP students exhibited low arches, and their plantar pressure distributions (PPDs) were mainly exerted on the left forefoot, as well as on the right forefoot and rearfoot. The weight shifted to the unaffected foot with dual plantar loading regions (forefoot and rearfoot), rather than the hemiplegic foot with a single region (forefoot). PPDs commonly increased at the medial metatarsals of both feet, and hemiplegic CP students presented the increased PPDs on the medial aspect of the hemiplegic foot accompanied by a rearfoot valgus posture pattern. The findings revealed a traceable feature to a possible connection among the pronated low arches, mild centers of gravity, metatarsal syndrome and rearfoot valgus of the hemiplegic limbs in CP patients.

Characteristics of Plantar Pressure with Foot Postures and Lower Limb Pain Profiles in Taiwanese College Elite Rugby League Athletes

Background: This study aimed to explore the differences in the distributions of plantar pressure in static and dynamic states and assess the possible pain profiles in the lower limb between elite rugby league athletes and recreational rugby players. Methods: A cross-sectional study of 51 college elite rugby athletes and 57 recreational rugby players was undertaken. The arch index (AI) and plantar pressure distributions (PPDs) with footprint characteristics were evaluated via the JC Mat. Rearfoot alignment was examined to evaluate the static foot posture. The elite group’s lower-limb pain profiles were examined for evaluating the common musculoskeletal pain areas. Results: The recreational group’s AI values fell into the normal range, whereas the elite group’s arch type fell into the category of the low arch. Results from the elite group were: (1) the PPDs mainly exerted on the entire forefoot and lateral midfoot regions in static standing, and transferred to the forefoot region during the midstance phase of walking; (2) the static rearfoot alignment matched the varus posture pattern; (3) the footprint characteristics illustrated the features of low-arched, supinated, dropped metatarsal heads and dropped cuboid feet; and (4) the phalanx and metatarsophalangeal joints, and the abductor hallucis and abductor digiti minimi of the plantar plate were common musculoskeletal pain areas. Conclusions: Characteristics of higher plantar loads beneath forefoot and midfoot associated with low-arched supinated feet in bipedal static stance could be the traceable features for the foot diagram of elite rugby league athletes. The limb pain profiles of the elite rugby league athletes within this study echoed the literature on rugby injuries, and reflected the features of metatarsophalangeal joint pains and dropped cuboids. The relationships among the low-arched supinated feet, metatarsophalangeal joint pains and cuboid syndrome are worth further studies.