Dorsal mobility and first ray stiffness in patients with diabetes mellitus

An Operational Definition of First Ray Hypermobility

BACKGROUND

The first ray (metatarsocuneiform) behaves as a load-bearing strut in supporting weight. Due to its functional importance, stress-testing techniques are used to assess the stability of the first ray and objectify evidence of hypermobility. The test and measurement of first ray hypermobility (FRH) is of interest to clinicians and researchers. The condition itself, however, has proven elusive to diagnose. This article defines FRH for the purpose of improving the consistency by which the diagnosis is made. Currently, the lack of a consensus definition prevents research from determining the incidence rates and prevalence of FRH, a commonly reported medical condition.

THE DEFINITION

Symptomatic FRH presents as dorsal displacement that measures greater than 8 mm, accompanied with signs and symptoms consistent with loading insufficiency of the first ray. The operational definition is objective and if adopted across health care professions, the criterion could become the standard for identifying FRH in patients and research participants.

LEVEL OF EVIDENCE

Level V, expert opinion.

Does a weight bearing equinus affect plantar pressure differently in older people with and without diabetes? A case control study

BACKGROUND

A weight bearing ankle equinus has adverse effects on forefoot plantar pressure variables in older adults with diabetes, but it is unclear if this is also the case in older adults without diabetes.

METHODS

40 older adults with diabetes (88% type 2, mean diabetes duration 17.6 ± 14.8 years) and 40 older adults without diabetes, matched for age (±3 years), sex and BMI (±2 BMI units) were included (63% female, mean age 72 ± 4 years, BMI 30 ± 4 kg/m²). Primary outcomes were prevalence of a weight bearing equinus and evaluation of barefoot forefoot plantar pressures in older adults with and without diabetes.

FINDINGS

A weight bearing equinus was present in 37.5% and 27.5% of the diabetes and non-diabetes group respectively with no significant difference between groups (p = 0.470). People with diabetes and equinus displayed higher peak pressure (808 versus 540 kPa, p = 0.065) and significantly higher pressure-time integral (86 versus 68 kPa/s, p = 0.030) than people with diabetes and no equinus group. The non-diabetes equinus group had significantly higher peak pressure (665 versus 567 kPa, p = 0.035) than those with no diabetes and no equinus, but no difference in pressure-time integral.

INTERPRETATION

A high prevalence of a weight bearing equinus was detected in older adults with and without diabetes, with associated increases in plantar pressures. As an equinus has been associated with many foot pathologies this study's findings suggest that clinicians should check for the presence of a weight bearing ankle equinus in all older adults.

Measurement of Dorsal First Ray Mobility: A Topical Historical Review and Commentary

Despite evidence that instability of the first ray (first metatarsal and medial cuneiform) alters the loading mechanics of the foot, surprisingly few studies have linked the condition with disorders of the foot. A factor limiting this research is the difficulty associated with measuring first ray mobility (FRM). To quantify dorsal FRM, clinicians and researchers have devised a variety of methods that impose a dorsally directed load, and record displacement. The methods include manual examination, radiographs, mechanical devices, and handheld rulers. Since different methods yield different results; each of these methods is worthy of scrutiny. This article reviews the methods used to quantify dorsal FRM and offers commentary on how the testing procedures could be standardized. The measurement of dorsal FRM informs surgical decisions, orthotic prescriptions, and research design strategies mostly as it pertains to the identification and treatment of first ray hypermobility. This review found sufficient support to recommend continued use of radiographs and mechanical devices for quantifying dorsal displacement, whereas measurements acquired with handheld rulers are prone to the same subjective error attributed to manual examination procedures. Since measures made with radiographs and existing mechanical devices have their own drawbacks, the commentary recommends ideas for standardizing the testing procedure and calls for the development of a next-generation device to measure dorsal FRM. This future device could be modeled after arthrometers that exist and are used to quantify stability at the knee and ankle. Level of Evidence: Level V, expert opinion.

A novel method of measuring passive quasi-stiffness in the first metatarsophalangeal joint

Background

First metatarsophalangeal joint (MTPJ) mobility is commonly assessed by its angular displacement (joint angle) or subjectively rated as ‘hypermobile’, ‘normal’ or ‘stiff’ by a clinician. Neither of these methods is ideal because displacement alone does not take into account the force required to displace the joint and subjective evaluation is not always reliable. This study presented a novel method to determine the passive quasi-stiffness of the first MTPJ. The reliability of the proposed method was also assessed. The first MTPJ passive quasi-stiffness of 13 healthy subjects were measured at two occasions, 7 days apart, by two testers (experienced and inexperienced). A tactile pressure sensing system was used to measure the force applied to dorsiflex the first toe by the testers. The torque (in Nmm) about the first MTPJ was calculated as the applied force (in N) multiplied by a moment arm (in mm), where moment arm was the length of the first proximal phalanx. A video camera recorded the motion of the first MTPJ, simultaneously with force measurements, to determine the joint angular displacement (in degrees) using the Dartfish software. The quasi-stiffness (in Nmm/degrees) was calculated as the slope of a graph where torque was plotted against first MTPJ angular displacement. Descriptive statistics of the first MTPJ quasi-stiffness were calculated. Intra-rater and inter-rater reliability were assessed using Bland and Altman plot, intraclass correlation coefficients (ICC), and standard error of measurement (SEM).

Results

First MTPJ quasi-stiffness of the subjects ranged widely from 0.66 to 53.4 Nmm/degrees. Intra-rater reliability for experienced tester was moderate (Session 1: 14.9 ± 14.6 Nmm/degrees, Session 2: 14.2 ± 8.5 Nmm/degrees, ICC = .568, SEM = 7.71 Nmm/degrees). Inter-rater reliability between experienced (12.6 ± 8.4 Nmm/degrees) and non-experienced (19.9 ± 9.2 Nmm/degrees) testers was poor (ICC = -.447, SEM = 11.29 Nmm/degrees).

Conclusions

First MTPJ passive quasi-stiffness can be quantified from torque and angular displacement measurements using simple equipment in a clinical setting. The tester’s experience affected the consistency in joint quasi-stiffness measurements.

Electronic supplementary material

The online version of this article (doi:10.1186/s13047-016-0173-2) contains supplementary material, which is available to authorized users.

Intralimb Coordination Patterns in Absent, Mild, and Severe Stages of Diabetic Neuropathy: Looking Beyond Kinematic Analysis of Gait Cycle

AIM

Diabetes Mellitus progressively leads to impairments in stability and joint motion and might affect coordination patterns, mainly due to neuropathy. This study aims to describe changes in intralimb joint coordination in healthy individuals and patients with absent, mild and, severe stages of neuropathy.

METHODS

Forty-seven diabetic patients were classified into three groups of neuropathic severity by a fuzzy model: 18 without neuropathy (DIAB), 7 with mild neuropathy (MILD), and 22 with moderate to severe neuropathy (SVRE). Thirteen healthy subjects were included as controls (CTRL). Continuous relative phase (CRP) was calculated at each instant of the gait cycle for each pair of lower limb joints. Analysis of Variance compared each frame of the CRP time series and its standard deviation among groups (α = 5%).

RESULTS

For the ankle-hip CRP, the SVRE group presented increased variability at the propulsion phase and a distinct pattern at the propulsion and initial swing phases compared to the DIAB and CTRL groups. For the ankle-knee CRP, the 3 diabetic groups presented more anti-phase ratios than the CTRL group at the midstance, propulsion, and terminal swing phases, with decreased variability at the early stance phase. For the knee-hip CRP, the MILD group showed more in-phase ratio at the early stance and terminal swing phases and lower variability compared to all other groups. All diabetic groups were more in-phase at early the midstance phase (with lower variability) than the control group.

CONCLUSION

The low variability and coordination differences of the MILD group showed that gait coordination might be altered not only when frank evidence of neuropathy is present, but also when neuropathy is still incipient. The ankle-knee CRP at the initial swing phase showed distinct patterns for groups from all degrees of neuropathic severity and CTRLs. The ankle-hip CRP pattern distinguished the SVRE patients from other diabetic groups, particularly in the transitional phase from stance to swing.

From treatment to preventive actions: improving function in patients with diabetic polyneuropathy

Diabetic polyneuropathy is an insidious and long-term complication of this disease. Synergistic treatments and preventive actions are crucial because there are no clear boundaries for determining when health professionals should intervene or what intervention would best avoid the consequences of neuropathy. Until now, most therapies to any diabetic individual were applied only after the patient's limb was ulcerated or amputated. The loss of muscle and joint functions is recognized as the main cause of plantar overloading. However, if foot and ankle exercises are performed following the early diagnosis of diabetes, they can enable the patient to maintain sufficient residual function to interact with the environment. This article summarizes the current knowledge about the musculoskeletal deficits and biomechanical alterations caused by neuropathy. It also describes the potential benefits of foot and ankle exercises for any diabetic patient that is not undergoing the plantar ulcer healing process. We concentrate on the prevention of the long-term deficits of neuropathy. We also discuss the main strategies and protocols of therapeutic exercises for joints and muscles with deficits, which are applicable to all diabetic patients with mild to moderate neuropathy. We describe further efforts in exploiting the applicability of assistive technologies to improve the adherence to an exercise program. Following the contemporary trends towards self-monitoring and self-care, we developed a software to monitor and promote personalized exercises with the aim of improving autonomous performance in daily living tasks. Initiatives to prevent the complications of functional diabetes are highly recommended before it is too late for the patient and there is no longer an opportunity to reverse the tragic consequences of neuropathy progression.

Variation of plantar pressure in Chinese diabetes mellitus

To investigate dynamic changes in plantar pressure in Chinese diabetes mellitus patients and to provide a basis for further preventing diabetic foot. This is a cross-sectional investigation including 649 Chinese diabetes mellitus patients (diabetes group) and 808 "normal" Chinese persons (nondiabetes group) with normal blood glucose levels. All the subjects provided a complete medical history and underwent a physical examination and a 75-g oral glucose tolerance test. All subjects walked barefoot with their usual gait, and their dynamic plantar forces were measured using the one-step method with a plantar pressure measurement instrument; 5 measurements were performed for each foot. No significant differences were found in age, height, body weight, or body mass index between the two groups. The fasting blood glucose levels, plantar contact time, maximum force, pressure-time integrals and force-time integrals in the diabetes group were significantly higher than those in the nondiabetes group (p < 0.05). However, the maximum pressure was significantly higher in the nondiabetes group than in the diabetes group (p < 0.05). No difference was found in the contact areas between the two groups (p > 0.05). The maximum plantar force distributions were essentially the same, with the highest force found for the medial heel, followed by the medial forefoot and the first toe. The peak plantar pressure was located at the medial forefoot for the nondiabetes group and at the hallucis for the diabetes group. In the diabetes group, the momentum in each plantar region was higher than that in the nondiabetes group; this difference was especially apparent in the heel, the lateral forefoot and the hallucis. The dynamic plantar pressures in diabetic patients differ from those in nondiabetic people with increased maximum force and pressure, a different distribution pattern and significantly increased momentum, which may lead to the formation of foot ulcers.

A comparison of customised and prefabricated insoles to reduce risk factors for neuropathic diabetic foot ulceration: a participant-blinded randomised controlled trial

BACKGROUND

Neuropathic diabetic foot ulceration may be prevented if the mechanical stress transmitted to the plantar tissues is reduced. Insole therapy is one practical method commonly used to reduce plantar loads and ulceration risk. The type of insole best suited to achieve this is unknown. This trial compared custom-made functional insoles with prefabricated insoles to reduce risk factors for ulceration of neuropathic diabetic feet.

METHOD

A participant-blinded randomised controlled trial recruited 119 neuropathic participants with diabetes who were randomly allocated to custom-made functional or prefabricated insoles. Data were collected at issue and six month follow-up using the F-scan in-shoe pressure measurement system. Primary outcomes were: peak pressure, forefoot pressure time integral, total contact area, forefoot rate of load, duration of load as a percentage of stance. Secondary outcomes were patient perceived foot health (Bristol Foot Score), quality of life (Audit of Diabetes Dependent Quality of Life). We also assessed cost of supply and fitting. Analysis was by intention-to-treat.

RESULTS

There were no differences between insoles in peak pressure, or three of the other four kinetic measures. The custom-made functional insole was slightly more effective than the prefabricated insole in reducing forefoot pressure time integral at issue (27% vs. 22%), remained more effective at six month follow-up (30% vs. 24%, p=0.001), but was more expensive (UK £656 vs. £554, p<0.001). Full compliance (minimum wear 7 hours a day 7 days per week) was reported by 40% of participants and 76% of participants reported a minimum wear of 5 hours a day 5 days per week. There was no difference in patient perception between insoles.

CONCLUSION

The custom-made insoles are more expensive than prefabricated insoles evaluated in this trial and no better in reducing peak pressure. We recommend that where clinically appropriate, the more cost effective prefabricated insole should be considered for use by patients with diabetes and neuropathy.

TRIAL REGISTRATION

Clinical trials.gov (NCT00999635). Note: this trial was registered on completion.

Diabetic foot problems in tertiary care diabetic clinic in Thailand

Foot problems in patients with diabetes cause substantial morbidity and may lead to lower extremity amputations. These risks may be reduced by appropriate screening and intervention measures. Effective screening assigns the patient to a risk category and dictates both the type and frequency of appropriate foot interventions. Less than half of diabetic patients in tertiary care hospital in Thailand received annual foot examination and there are limited data available on the nature of foot problems in such setting. This study reported a cross-sectional data of 438 diabetic patients attend tertiary diabetic clinic in the university hospital in Northern Thailand. Neuropathy manifestations as skin dryness, limitation of joint mobility and insensate to monofilament was the most common manifestation of diabetic foot problems in this setting. Most patients were not protected by proper footwear. More effort is needed to educate diabetic patients about foot care and improve their choice and selection of footwear.

Effects of a combined strengthening, stretching and functional training program versus usual-care on gait biomechanics and foot function for diabetic neuropathy: a randomized controlled trial

Background

Polyneuropathy is a complication of diabetes mellitus that has been very challenging for clinicians. It results in high public health costs and has a huge impact on patients' quality of life. Preventive interventions are still the most important approach to avoid plantar ulceration and amputation, which is the most devastating endpoint of the disease. Some therapeutic interventions improve gait quality, confidence, and quality of life; however, there is no evidence yet of an effective physical therapy treatment for recovering musculoskeletal function and foot rollover during gait that could potentially redistribute plantar pressure and reduce the risk of ulcer formation.

Methods/Design

A randomised, controlled trial, with blind assessment, was designed to study the effect of a physiotherapy intervention on foot rollover during gait, range of motion, muscle strength and function of the foot and ankle, and balance confidence. The main outcome is plantar pressure during foot rollover, and the secondary outcomes are kinetic and kinematic parameters of gait, neuropathy signs and symptoms, foot and ankle range of motion and function, muscle strength, and balance confidence. The intervention is carried out for 12 weeks, twice a week, for 40-60 min each session. The follow-up period is 24 weeks from the baseline condition.

Discussion

Herein, we present a more comprehensive and specific physiotherapy approach for foot and ankle function, by choosing simple tasks, focusing on recovering range of motion, strength, and functionality of the joints most impaired by diabetic polyneuropathy. In addition, this intervention aims to transfer these peripheral gains to the functional and more complex task of foot rollover during gait, in order to reduce risk of ulceration. If it shows any benefit, this protocol can be used in clinical practice and can be indicated as complementary treatment for this disease.

Trial Registration

ClinicalTrials.gov Identifier: NCT01207284

Mobility of the first ray: review article

Since its introduction by Morton in the early 20th century, first metatarsal instability has been debated as a contributing cause of many foot ailments. Given our evolutionary origins, some instability at the first ray seems inevitable. It makes sense that hypermobility could be the pathology leading to the development of various forefoot disorders. The problem is that it has been difficult to prove. Only in the last decade have there been any devices with which to quantify mobility, and each of the devices measures slightly different variables. However, each of these devices has been shown to be consistent and reliable. Excessive mobility of the first ray probably cannot be considered the only "suspect." With disorders such as hallux valgus and metatarsalgia, environment and footwear may play just as important a role as hypermobility. There are some conclusions, though, that can be safely drawn at this point. * We should define the measures of first ray mobility. One recent study has suggested the terms metatarsal elevation and metatarsal translation to describe two different aspects of the problem. * Simple clinical tools may be as useful as more cumbersome research tools for assessing first ray instability. * First ray mobility on average is increased in patients with hallux valgus. * First ray mobility is increased in some patients with transfer metatarsalgia. * Although some studies show increased elevation or mobility of the first ray in hallux rigidus, other studies do not. The burden is on the current generation of foot and ankle practitioners to resolve the debate of its predecessors. By first defining the measures of instability and then applying them to large populations, the role of hypermobility may be better defined. Then we can debate how best to "fix" the problem!

First ray mobility increase in patients with metatarsalgia

BACKGROUND

The significance and measurement of first metatarsal hypermobility has been difficult to quantify in relation to transfer metatarsalgia. We evaluated the hypothesis that dynamic elevation of the first metatarsal relative to the second metatarsal could be measured with a simple device and would be associated with transfer metatarsalgia. We also assessed intraobserver and interobserver reliability of the simple device.

MATERIALS AND METHODS

A series of 352 patients were prospectively measured for dynamic metatarsal elevation: 64 patients with transfer metatarsalgia and 288 patients without symptoms.

RESULTS

Those with metatarsalgia symptoms had significantly greater first ray mobility (9 mm versus 7 mm; p < 0.0002) and metatarsal elevation (5 mm versus 3 mm; p < 0.0002) than patients without symptoms.

CONCLUSION

In this prospective series, the device was reliable for measuring dynamic first metatarsal elevation at different time points with different examiners. Patients with metatarsalgia had higher dynamic metatarsal elevation compared to patients without metatarsalgia, suggesting a mechanism by which load can be transferred from the first to lesser metatarsals.

Relationships between segmental foot mobility and plantar loading in individuals with and without diabetes and neuropathy

The purpose of our study was to examine dynamic foot function during gait as it relates to plantar loading in individuals with DM (diabetes mellitus and neuropathy) compared to matched control subjects. Foot mobility during gait was examined using a multi-segment kinematic model, and plantar loading was measured using a pedobarograph in subjects with DM (N = 15), control subjects (N = 15). Pearson product moment correlation was used to assess the relationship between variables of interest. Statistical significance and equality of correlations were assessed using approximate tests based on Fisher's Z transformation (alpha = 0.05). In individuals with DM, first metatarsal sagittal plane excursion during gait was negatively associated with pressure time integral under the medial forefoot (r = -0.42 and -0.06, DM and Ctrl, P = 0.02). Similarly, lateral forefoot sagittal plane excursion during gait was negatively associated with pressure time integral under the lateral forefoot (r = -0.56 and -0.11, DM and Ctrl, P = 0.02). Frontal plane excursion of the calcaneus was negatively associated with medial (r = -0.57 and 0.12, DM and Ctrl, P < 0.01) and lateral (r = -0.51 and 0.13, DM and Ctrl, P < 0.01) heel and medial forefoot pressure time integral (r = -0.56 and -0.02, DM and Ctrl, P < 0.01). The key findings of our study indicate that reductions in segmental foot mobility were accompanied by increases in local loading in subjects with DM. Reduction in frontal plane calcaneal mobility during walking serves as an important functional marker of loss of foot flexibility in subjects with DM.

Hallux valgus and the first metatarsal arch segment: a theoretical biomechanical perspective

Hallux valgus is a progressive foot deformity characterized by a lateral deviation of the hallux with corresponding medial deviation of the first metatarsal. Late-stage changes may render the hallux painful and without functional utility, leading to impaired gait. Various environmental, genetic, and anatomical predispositions have been suggested, but the exact cause of hallux valgus is unknown. Evidence indicates that conservative intervention for hallux valgus provides relief from symptoms but does not reverse deformity. Part 1 of this perspective article reviews the literature describing the anatomy, pathomechanics, and etiology of hallux valgus. Part 2 expands on the biomechanical initiators of hallux valgus attributed to the first metatarsal. Theory is advanced that collapse of the arch with vertical orientation (tilt) of the first metatarsal axis initiates deformity. To counteract the progression of hallux valgus, we use theory to discuss a possible mechanism by which foot orthoses can bolster the arch and reorient the first metatarsal axis horizontally.

Midfoot charcot arthropathy with improvement of arch after achilles tendon lengthening: a case report

Level of Evidence: V, Expert Opinion

Diabetic Neuropathy Is Related to Joint Stiffness during Late Stance Phase

The majority of plantar ulcers in the diabetic population occur in the forefoot. Peripheral neuropathy has been related to the occurrence of ulcers. Long-term diabetes results in the joints becoming passively stiffer. This static stiffness may translate to dynamic joint stiffness in the lower extremities during gait. Therefore, the purpose of this investigation was to demonstrate differences in ankle and knee joint stiffness between diabetic individuals with and without peripheral neuropathy during gait. Diabetic subjects with and without peripheral neuropathy were compared. Subjects were monitored during normal walking with three-dimensional motion analysis and a force plate. Neuropathic subjects had higher ankle stiffness (0.236 N·m/ deg) during 65 to 80% of stance when compared with non-neuropathic subjects (−0.113 N·m/deg). Neuropathic subjects showed a different pattern in ankle stiffness compared with non-neuropathic subjects. Neuropathic subjects demonstrated a consistent level of ankle stiffness, whereas non-neuropathic subjects showed varying levels of stiffness. Neuropathic subjects demonstrated lower knee stiffness (0.015 N·m/deg) compared with non-neuropathic subjects (0.075 N·m/deg) during 50 to 65% of stance. The differences in patterns of ankle and knee joint stiffness between groups appear to be related to changes in timing of peak ankle dorsiflexion during stance, with the neuropathic group reaching peak dorsiflexion later than the non-neuropathic subjects. This may partially relate to the changes in plantar pressures beneath the metatarsal heads present in individuals with neuropathy.

Segmental foot mobility in individuals with and without diabetes and neuropathy

BACKGROUND

Impairment in intrinsic foot mobility has been identified as an important potential contributor to altered foot function in individuals with diabetes mellitus and neuropathy, however the role of limited foot mobility in gait remains poorly understood. The purpose of our study was to examine segmental foot mobility during gait in subjects with and without diabetes and neuropathy.

METHODS

Segmental foot mobility during gait was examined using a multi-segment kinematic foot model in subjects with diabetes (n=15) and non-diabetic control subjects (n=15).

FINDINGS

Subjects with diabetes showed reduced frontal as well as sagittal plane excursion of the calcaneus relative to the tibia. Decreased excursion of the first metatarsal relative to the calcaneus in the frontal as well as transverse plane was noted in subjects with diabetes.

INTERPRETATION

Our findings agree with traditional understanding of foot mechanics and shed new light on patterns and magnitude of motion during gait. Calcaneal pronation, noted in early stance in both groups, was reduced in subjects with diabetes and may have important consequences on joints proximal as well as distal to it. Subjects with diabetes showed reduced foot 'splay' in early stance, indicated by first metatarsal and forefoot eversion. At terminal stance, decreases in calcaneal plantarflexion, first metatarsal and forefoot supination were noted in subjects with diabetes, suggesting that less supination is required in subjects with diabetes to create a rigid lever. In subjects with diabetes, a greater proportion of midfoot stability may be derived from modified/stiffer soft tissue such as the plantar fascia.

Diabetes mellitus

Dermatologic problems are common in diabetes, with approximately 30% of patients experiencing some cutaneous involvement during the course of their illness. Skin manifestations generally appear during the course of the disease in patients known to have diabetes, but they may also be the first presenting sign of diabetes or even precede the diagnosis by many years. The skin involvement can be autoimmune in nature, such as acanthosis nigricans, necrobiosis lipoidica, diabetic dermopathy, scleredema, and granuloma annulare, or infectious in the form of erythrasma, necrotizing fasciitis, and mucormycosis. Pharmacologic management of diabetes, in addition, can also result in skin changes, such as lipoatrophy and lipohypertrophy, at the site of injection of insulin, and oral antidiabetic agents can cause multiple skin reactions as adverse effects. The management of these cutaneous manifestations is tailored according to the underlying pathophysiology, but a tight control of blood glucose is a prerequisite in all management strategies.

Increased passive ankle stiffness and reduced dorsiflexion range of motion in individuals with diabetes mellitus

BACKGROUND

The purpose of our study was to compare ankle range of motion and stiffness in individuals with and without diabetes mellitus using a reliable and valid technique and to document the effect of knee flexion and severity of pathology on ankle range of motion and stiffness.

METHODS

Twenty-five individuals with diabetes mellitus and 64 nondiabetic individuals, similar in age and gender profile, participated in this study.

RESULTS

Results revealed that individuals with diabetes mellitus had both significantly lower peak dorsiflexion range of motion (5.1 and 11.5 degrees, p < 0.001) and higher passive ankle stiffness (0.016 and 0.008 Nm/kg/degree, p < 0.01) than non-diabetic individuals. In individuals with diabetes mellitus, a positive relationship between glycemic control and duration of diabetes mellitus and ankle stiffness ((r(2) = 0.48 and 0.24 respectively, p < 0.01 for both) was found.

CONCLUSION

While decreased range of motion and increased stiffness in the diabetes mellitus population seem clinically intuitive, as far as we know this is the first study to confirm the concurrent existence of both these findings in the plantarflexors in individuals with diabetes mellitus. We applied a reliable and valid technique, one that allowed control of confounding factors such as knee flexion position and differences in determination of end range of motion, and documented a mean 41% loss in dorsiflexion excursion. Changes in the muscle, stemming from underlying pathology, are hypothesized to account for a significant part of the lost range of motion. Changes in ankle range of motion and stiffness may have important implications in plantar loading and ulcer formation.

The influence of first ray mobility on forefoot plantar pressure and hindfoot kinematics during walking

BACKGROUND

Hypomobility and hypermobility of the first ray have been implicated in the literature as a primary cause of mechanical foot problems because of proposed obligatory and compensatory movements. Despite these theoretical links, research is sparse regarding the effect on kinematic and plantar pressure patterns as a result of altered first ray mobility. The purpose of this study was to determine whether hypomobility or hypermobility of the first ray alters hindfoot kinematics or the distribution of plantar pressures during walking.

METHODS

The magnitude of dorsal first ray mobility in 82 individuals was measured and then classified as being hypomobile, normal, or hypermobile. The plantar pressure under the first and second metatarsal heads, as well as hindfoot kinematics during walking, were then compared between the three categories of first ray mobility.

RESULTS

The results of this study indicate that those feet with a hypomobile first ray had significantly decreased plantar force and pressure values under the first metatarsal compared to the second metatarsal. In addition, feet with a hypomobile first ray showed significantly more hindfoot eversion compared to those with either normal or hypermobile first rays.

CONCLUSION

The results of this study do not support the common theoretical implications of altered mobility of the first ray related to plantar pressure and hindfoot kinematics.

A critical analysis of Dudley Morton's concept of disordered foot function

The name Morton is associated with a foot structure characterized by a short first metatarsal in comparison with the adjacent second metatarsal. Dudley Morton is credited with recognizing a short first metatarsal as being a primary defect of the foot. Morton, an anatomist, approached his observation from an evolutionary perspective. His theory of disordered foot function was based on the premise that human alignment centered on an "axis of leverage" and around an "axis of balance." Morton concluded that the presence of a short first metatarsal was compounded when the first metatarsal segment was hypermobile. Shortness and hypermobility diminished the capacity of the first metatarsal segment to carry weight, allowed pronation during activity, and led to an overload of the central metatarsals. The term Morton Foot sprang from his teachings. The extensive writings of Morton are commonly cited even today. This study compares Morton's teachings with research published during the last 70 years, which either supports or refutes his claims.

A comparison of device measures of dorsal first ray mobility

BACKGROUND

Devices built by Glasoe and Klaue have been used in several studies to measure first ray mobility. Both devices measure sagittal motion of the first ray in a dorsal direction. The primary difference in the devices is the method of the load imposed. This study investigates whether first ray mobility measured with the Glasoe device is similar to the amount of mobility measured with the Klaue device.

METHODS

Using the devices described by Glasoe and Klaue, dorsal first ray mobility was measured in 39 patients who had foot and ankle problems. Paired t-tests were computed to assess for differences between device measures of dorsal mobility. Intraclass correlation coefficient (ICC) and absolute difference values were computed to further assess the agreement in measures.

RESULTS

Dorsal mobility measured with the Glasoe device averaged 4.9 mm (1.8 to 9.3 mm). Dorsal mobility measured with the Klaue device averaged 5.2 mm (2.5 to 8.5 mm). Paired t-tests (p = 0.12) revealed no significant difference in measures. An ICC of 0.70 and a mean absolute difference of 0.9 mm (SD 0.8) were found between the two clinical measures further suggesting agreement.

CONCLUSION

Results indicated that the two devices possess similar diagnostic accuracy in the measurement of dorsal first ray mobility.