Alfred Gatt

Clinical assessment of ankle joint dorsiflexion : A review of measurement techniques

Ankle dorsiflexion measurement is important for clinical and research use. With so much evidence on the unreliability of goniometric measurements, a systematic review was performed to investigate various alternative techniques for measuring ankle dorsiflexion in the nonneurologic patient. All of the major databases were queried electronically to identify studies that used any method of ankle dorsiflexion measurement in the nonneurologic subject. Keywords included ankle dorsiflexion NOT cerebral palsy NOT stroke, the latter to exclude neurologic conditions. In 755 studies that used some form of ankle joint dorsiflexion measurement, ten different techniques were identified that included various apparatuses designed specifically for this purpose. Reliability testing of these techniques involved test-retest trials with small student populations as subjects, which returned high intraclass correlation coefficient scores. However, their methodological quality would have benefitted from the use of an actual patient population and comparison with a reference standard. When validating ankle dorsiflexion measurement techniques, actual patient populations should be used, otherwise papers would score poorly on methodological quality assessment. Standardizing patient position, foot posture, amount of moment applied, and reference landmarks will ensure that various trial results can be compared directly.

Thermographic Patterns of the Upper and Lower Limbs: Baseline Data

Objectives. To collect normative baseline data and identify any significant differences between hand and foot thermographic distribution patterns in a healthy adult population. Design. A single-centre, randomized, prospective study. Methods. Thermographic data was acquired using a FLIR camera for the data acquisition of both plantar and dorsal aspects of the feet, volar aspects of the hands, and anterior aspects of the lower limbs under controlled climate conditions. Results. There is general symmetry in skin temperature between the same regions in contralateral limbs, in terms of both magnitude and pattern. There was also minimal intersubject temperature variation with a consistent temperature pattern in toes and fingers. The thumb is the warmest digit with the temperature falling gradually between the 2nd and the 5th fingers. The big toe and the 5th toe are the warmest digits with the 2nd to the 4th toes being cooler. Conclusion. Measurement of skin temperature of the limbs using a thermal camera is feasible and reproducible. Temperature patterns in fingers and toes are consistent with similar temperatures in contralateral limbs in healthy subjects. This study provides the basis for further research to assess the clinical usefulness of thermography in the diagnosis of vascular insufficiency.

The importance of clinical biomechanical assessment of foot deformity and joint mobility in people living with type-2 diabetes within a primary care setting

AIMS The aim of the study was to assess foot morphology and document foot deformities and joint mobility in a cohort of subjects living with type-2 diabetes mellitus in Malta in a Primary Care setting. METHODS A retrospective observational study was conducted on 243 subjects who participated in a local pilot diabetes foot screening project. Assessments included hammer/claw toes, hallux valgus, hallux limitus, prominent metatarsal heads, bony prominences, Charcot deformity, plantar callus, foot type and ankle and hallux mobility. The clinical assessments used during this screening program were based on validated and previously published tools. RESULTS Upon clinical examination 38% of the sample was found to have developed some form of corns or callosities in their feet. Hallux valgus deformity was present in 49.4% of the sample, whilst 39% of the sample had hammer toes. Prominent metatarsal heads (24%), other bony prominences (44%) and limited joint mobility were also reported. Furthermore, 56% of the sample presented with unsuitable footwear and upon clinical biomechanical examination a further 28% of the sample required prescription orthosis. CONCLUSIONS/INTERPRETATION A significant proportion of participants living with type-2 diabetes presented with foot deformities which are known to be predictive of foot ulceration in this high risk population. This research conducted in a primary care setting highlights the importance of increased vigilance coupled with strengthening of existing screening structures and introducing clinical guidelines with regards to biomechanical assessment of the feet in a primary care setting in order to reduce the incidence of diabetes foot complications.

Diabetic foot complications in Malta: Prevalence of risk factors

AIMS The main objective of this research was to identify the prevalence of diabetes-related lower-extremity complications in a cohort of Maltese patients living with type 2 diabetes. METHODS A retrospective study was conducted on a cohort of 243 patients living with type 2 diabetes mellitus in two Maltese Health Centre catchment areas. A convenience sampling was adopted to recruit subjects from a local pilot diabetes foot screening program. The clinical assessments used during this screening program were based on validated and previously published tools such as: neuropathy disability score, vibration perception threshold, Semmes-Weinstein monofilaments, vascular status and foot deformities were evaluated. RESULTS The results from this study demonstrate that risk factors for foot deterioration and ulceration are common in Maltese population living with type 2 diabetes. Whilst, metabolic outcomes such as hypertension and dyslipidaemia were present in most subjects, peripheral vascular disease, peripheral sensory neuropathy and foot deformities were also common. Twenty-six per cent of the sample had to be referred for further vascular assessment following this screening program due to their critical vascular status. CONCLUSIONS/INTERPRETATION A significant proportion of Maltese participants living with type 2 diabetes presented with vascular insufficiency, abnormal neural function and deformities in the feet. Metabolic outcomes such as high blood pressure and high levels of cholesterol were also highly prevalent. Strengthening of existing screening structures is imperative in order to reduce the burden of this disease in Malta.

Negative Poisson's ratios in tendons: An unexpected mechanical response.

UNLABELLED Tendons are visco-elastic structures that connect bones to muscles and perform the basic function of force transfer to and from the skeleton. They are essential for positioning as well as energy storing when involved in more abrupt movements such as jumping. Unfortunately, they are also prone to damage, and when injuries occur, they may have dilapidating consequences. For instance, there is consensus that injuries of tendons such as Achilles tendinopathies, which are common in athletes, are difficult to treat. Here we show, through in vivo and ex vivo tests, that healthy tendons are highly anisotropic and behave in a very unconventional manner when stretched, and exhibit a negative Poissons ratio (auxeticity) in some planes when stretched up to 2% along their length, i.e. within their normal range of motion. Furthermore, since the Poissons ratio is highly dependent on the materials microstructure, which may be lost if tendons are damaged or diseased, this property may provide a suitable diagnostic tool to assess tendon health. STATEMENT OF SIGNIFICANCE We report that human tendons including the Achilles tendons exhibits the very unusual mechanical property of a negative Poissons ratio (auxetic) meaning that they get fatter rather than thinner when stretched. This report is backed by in vivo and ex vivo experiments we performed which clearly confirm auxeticity in this living material for strains which correspond to those experienced during most normal everyday activities. We also show that this property is not limited to the human Achilles tendon, as it was also found in tendons taken from sheep and pigs. This new information about tendons can form the scientific basis for a test for tendon health as well as enable the design of better tendon prosthesis which could replace damaged tendons.

Validity and reliability of a new ankle dorsiflexion measurement device

Background: The assessment of the maximum ankle dorsiflexion angle is an important clinical examination procedure. Evidence shows that the traditional goniometer is highly unreliable, and various designs of goniometers to measure the maximum ankle dorsiflexion angle rely on the application of a known force to obtain reliable results. Hence, an innovative ankle dorsiflexion measurement device was designed to make this measurement more reliable by holding the foot in a selected posture without the application of a known moment. Objectives: To report on the comprehensive validity and reliability testing carried out on the new device. Methods: Following validity testing, four different trials to test reliability of the ankle dorsiflexion measurement device were performed. These trials included inter-rater and intra-rater testings with a controlled moment, intra-rater reliability testing with knees flexed and extended without a controlled moment, intra-rater testing with a patient population, and inter-rater reliability testing between four raters of varying experience without controlling moment. All raters were blinded. Study Design: A series of trials to test intra-rater and inter-rater reliabilities. Results: Intra-rater reliability intraclass correlation coefficient was 0.98 and inter-rater reliability intraclass correlation coefficient (2,1) was 0.953 with a controlled moment. With uncontrolled moment, very high reliability for intra-tester was also achieved (intraclass correlation coefficient = 0.94 with knees extended and intraclass correlation coefficient = 0.95 with knees flexed). For the trial investigating test–retest reliability with actual patients, intraclass correlation coefficient of 0.99 was obtained. In the trial investigating four different raters with uncontrolled moment, intraclass correlation coefficient of 0.91 was achieved. Conclusions: The new ankle dorsiflexion measurement device is a valid and reliable device for measuring ankle dorsiflexion in both healthy subjects and patients, with both controlled and uncontrolled moments, even by multiple raters of varying experience when the foot is dorsiflexed to its end of range of motion. Clinical relevance An ankle dorsiflexion measuring device has been designed to increase the reliability of ankle dorsiflexion measurement and replace the traditional goniometer. While the majority of similar devices rely on application of a known moment to perform this measurement, it has been shown that this is not required with the new ankle dorsiflexion measurement device and, rather, foot posture should be taken into consideration as this affects the maximum ankle dorsiflexion angle.

Hidden dangers revealed by misdiagnosed peripheral arterial disease using ABPI measurement

AIM The aim of this study was to compare ankle brachial indices (APBI) with pedal waveforms utilizing the continuous wave Doppler in a population with diabetes mellitus. METHODS A prospective study design was employed to investigate the ABPI in a cohort of 49 people with type 2 diabetes mellitus. ABPI assessment was completed using a portable handheld Doppler and ankle pressures of <0.9 were taken as suggestive of peripheral arterial disease (PAD). Arterial spectral waveforms in each foot were also recorded and compared to the ABPI readings. RESULTS Inconsistencies were identified between ABPIs and waveform interpretations in the study population. Approximately 35% of subjects had inconsistencies between their ABPI result and waveform interpretation in their right or left foot. CONCLUSIONS Both ABPIs and Doppler waveforms should be used in the assessment of people with diabetes in order to screen for PAD. This would ensure an accurate assessment of PAD and would allow initiation of appropriate secondary risk factor control measures.

Sagittal plane kinematics of the foot during passive ankle dorsiflexion

Background: Measurement of ankle joint dorsiflexion is an essential examination technique that needs to be performed prior to prescription of foot orthoses since the presence or absence of ankle equinus will affect the design of such devices. The purpose of this study was to investigate the effect of foot posture on sagittal plane kinematics of various foot segments during passive dorsiflexion. Study Design: Comparative repeated measures design. Objectives: To determine the effect of foot posture on inter segmental kinematics during passive dorsiflexion. Methods: An optoelectronic movement analysis system was employed to collect kinematic data. A validated marker set (Oxford Foot Model) was applied to 16 subjects (12 males, 4 females) with a mean age of 35.5 years (range 20–56 years), who provided informed consent. An upward force was applied to the forefoot until maximum resistance. Sagittal movement of the hindfoot and forefoot segments along with the whole foot movement were analyzed in the pronated, neutral and supinated foot postures. Results: While maximum foot dorsiflexion angle showed a significant difference between the three postures (p=0.000) the actual recorded difference between the neutral and supinated postures was only 2.49°. For the hindfoot and forefoot segments, mean angle range of movement for the pronated foot posture was significantly higher than the other foot postures. The forefoot to hindfoot angle demonstrated a significant (p=0.005) increase during dorsiflexion between the pronated and supinated postures. These results indicate that during passive dorsiflexion, the forefoot travels through a greater degree of movement than the hindfoot. Conclusions: While the maximum foot dorsiflexion angle differs significantly between the pronated and supinated foot postures, hindfoot movement also varies significantly between foot postures. Furthermore, the forefoot to tibia angle travels through a greater range than the hindfoot to tibia angle, in all three foot postures. The hindfoot to forefoot angle does not remain constant during passive dorsiflexion, but increases upon application of a dorsiflexing force, indicating that the forefoot movement cannot be eliminated completely by placing the foot in any particular posture.

Shock attenuation properties at heel strike: Implications for the clinical management of the cavus foot.

BACKGROUND This study explored the relationship between foot types and corresponding variations in shock attenuating properties of the heel. METHODS Thirty matched participants were assigned to 3 groups: pronated, neutral, and supinated. A low-mass accelerometer was mounted to the calcaneus of the right leg of each participant. RESULTS Acceleration at heel strike for supinators was significantly higher than that in individuals with pronated and neutrally aligned feet. No significant difference was found in mean and maximum acceleration at heel strike between pronators and neutrals. CONCLUSION Cavus feet undergo significantly higher mean and maximum acceleration forces than neutrally aligned and pronated feet.

Establishing Differences in Thermographic Patterns between the Various Complications in Diabetic Foot Disease

Aim To evaluate the potential of thermography as an assessment tool for the detection of foot complications by understanding the variations in temperature that occur in type 2 diabetes mellitus (DM). Methods Participants were categorized according to a medical examination, ankle brachial index, doppler waveform analysis, and 10-gram monofilament testing into five groups: healthy adult, DM with no complications, DM with peripheral neuropathy, DM with neuroischaemia, and DM with peripheral arterial disease (PAD) groups. Thermographic imaging of the toes and forefeet was performed. Results 43 neuroischaemic feet, 41 neuropathic feet, 58 PAD feet, 21 DM feet without complications, and 126 healthy feet were analyzed. The temperatures of the feet and toes were significantly higher in the complications group when compared to the healthy adult and DM healthy groups. The higher the temperatures of the foot in DM, the higher the probability that it is affected by neuropathy, neuroischaemia, or PAD. Conclusions Significant differences in mean temperatures exist between participants who were healthy and those with DM with no known complications when compared to participants with neuroischaemia, neuropathy, or PAD. As foot temperature rises, so does the probability of the presence of complications of neuropathy, neuroischaemia, or peripheral arterial disease.