Relationships between plantar flexor muscle stiffness, strength, and range of motion in subjects with diabetes-peripheral neuropathy compared to age-matched controls

The effects of the use of customized silicone digital orthoses on pre-ulcerative lesions and plantar pressure during walking in people with diabetic neuropathy: A study protocol for a randomized controlled trial

Background

People with diabetes and diabetic peripheral neuropathy (DPN) often develop calluses due to toe misalignment and increased plantar pressure. Untreated, these issues can progress into ulcers, making early intervention crucial. This trial protocol aims to evaluate the efficacy and safety of customized silicone digital orthoses in preventing ulcers, pre-ulcerative lesions, and peak pressure during gait in people with DPN.

Methods

In this superiority randomized controlled parallel trial with single-blind assessment, 60 participants will be allocated to the control group (CG) or the intervention group (IG). The CG will receive specialized nurse-administered foot care, including callus removal, nail care guidance, and self-care education. The IG will receive the same care plus a customized silicone orthosis for toe realignment for 6 months. Assessments will occur at baseline and 3 and 6 months for the primary outcomes (pre-ulcerative lesions and ulcer incidence) and secondary outcomes (pressure distribution, foot function and health, quality of life, safety, and comfort). Two-way ANOVAs (p < .05) will assess group, time, and group by time effects following an intention-to-treat approach.

Conclusion

Although recommended for foot ulcer prevention, custom silicone orthosis adoption remains limited due to the low certainty of evidence. This trial seeks to provide more consistent evidence for the use of toe orthoses in preventing callus and ulcer formation for individuals with DPN.

Trial registry

ClinicalTrials.gov (NCT05683106) "Effects of Customized Silicone Digital Orthoses in People with Diabetic Neuropathy" (registered on December 20, 2022).

Effect of Core Balance Training on Muscle Tone and Balance Ability in Adult Men and Women

(1) Background: The amount of physical activity most adults perform is less than the recommended amount, and the resulting decrease in physical strength makes them vulnerable to various diseases. A decrease in muscle size and strength due to damage caused by disease or aging negatively affects functional strength. Muscle evaluation in adults can yield results that are predictive indicators of aging and unexpected disability. In addition, balance ability is essential to prevent falls and injuries in daily life and maintain functional activities. It is important to develop and strengthen balance in the lower extremities and core muscles to maintain and enhance overall body balance. This study aimed to analyze the effects of core balance training on muscle tone and balance ability in adults. (2) Methods: The participants of this study were 32 adult male and female university students (male: mean age = 21.3 ± 1.9 years, weight = 74.2 ± 12.6 kg, BMI = 23.4 + 2.5, n = 14; female: mean age = 21.0 ± 1.4 years, weight = 64.6 + 1.2 kg, BMI = 22.4 ± 2.4, n =18). Thirty-two adults (training group: 16, control group: 16; male: 16, female: 16) participated in the Myoton PRO (gastrocnemius lateral/medial, tibialis anterior), Pedalo balance system, and Y-balance test. (3) Results: The following results were obtained for muscle elasticity, stiffness, and dynamic/static balance ability after 10 weeks of core balance training. 1. There was no significant difference in muscle elasticity (gastrocnemius lateral/medial, tibialis anterior) (p < 0.05). 2. Muscle stiffness (gastrocnemius lateral/medial, tibialis anterior) significantly increased (p < 0.05). 3. Dynamic/static balance ability significantly increased (p < 0.05). (4) Conclusions: In future, data for the age and sex of various participants, should be accumulated by recruiting participants to study muscle characteristics, such as muscle elasticity and stiffness. Estimating the appropriate injury range and optimal exercise capacity is possible through follow-up studies. The findings can then be used as a basis for predicting injuries or determining and confirming the best time to resume exercise.

Midfoot and ankle movement coordination during heel rise is disrupted in people with diabetes and peripheral neuropathy

BACKGROUND

A heel rise task can be used to evaluate midfoot and ankle movement dysfunction in people with diabetes mellitus and peripheral neuropathy. Quantifying movement coordination during heel rise is important to better understand potentially detrimental movement strategies in people with foot pathologies; however, coordination and the impact of limited excursion on coordination is not well-understood in people with diabetes.

METHODS

Sixty patients with diabetes mellitus and peripheral neuropathy, and 22 older and 25 younger controls performed single-limb heel rise task. Midfoot (forefoot relative to hindfoot) sagittal and ankle (hindfoot relative to shank) sagittal and frontal kinematics were measured and normalized to time (0 to 100%). Cross-correlation coefficients were calculated across individuals in each group. A graphical illustration was used to interpret the relationship of midfoot and ankle excursion and cross-correlation coefficient during heel rise.

FINDINGS

People with diabetes mellitus and peripheral neuropathy showed significantly lower midfoot and ankle cross-correlation coefficients during heel rise compared to older controls (p = 0.003-0.007). There was no difference in the midfoot and ankle cross-correlation coefficients during heel rise for the older and younger controls (p = 0.059-0.425). The graphic data illustrated a trend of greater excursion of two joints and a higher cross-correlation coefficient. Some individuals with lower excursion showed a high cross-correlation coefficient.

INTERPRETATION

Foot pathologies, but not aging, impairs midfoot and ankle movement coordination during heel rise task. Investigating both movement coordination as well as joint excursion would better inform and characterize the dynamic movements of midfoot and ankle during heel rise task.

Ankle Proprioception in Patients with Type 2 Diabetes Mellitus

BACKGROUND

Ankle position sense may be reduced before the appearance of the clinical manifestation of diabetic peripheral neuropathy. This is known to impair gait and cause falls and foot ulcers. Early detection of impaired ankle proprioception is important because it allows physicians to prescribe an exercise program to patients to prevent foot complications.

METHODS

Forty-six patients diagnosed as having type 2 diabetes mellitus and 22 control patients were included in the study. Presence of neuropathy was assessed using the Michigan Neuropathy Screening Instrument (MNSI). Level of foot care awareness was determined using the Nottingham Assessment of Functional Footcare (NAFF). Joint position sense was measured using a dynamometer.

RESULTS

Mean absolute angular error (MAAE) values were significantly higher in the neuropathy group compared with the control group (P < .05). Right plantarflexion MAAE values were significantly lower in the group without neuropathy compared with the group with neuropathy (P < .05). No correlation was found between MAAE values (indicating joint position sense) and age, educational level, disease duration, glycemic control, NAFF score, and MNSI history and examination scores in the groups with and without neuropathy (P > .05). Educational level and disease duration were found to be correlated with NAFF scores.

CONCLUSIONS

Increased MNSI history scores and increased deficits in ankle proprioception demonstrate that diabetic foot complications associated with reduced joint position sense may be seen at an increased rate in symptomatic patients.

Foot-ankle functional outcomes of using the Diabetic Foot Guidance System (SOPeD) for people with diabetic neuropathy: a feasibility study for the single-blind randomized controlled FOotCAre (FOCA) trial I

BACKGROUND

Diabetic neuropathy dramatically affects musculoskeletal structure and function of the lower limbs by impairing their muscle strength and mobility. Specific muscle strengthening through physiotherapy strategies appears to be promising; however, adherence to physiotherapy treatment is low in people with chronic diseases. Thus, an internet-based foot-ankle exercise program was created as a potential telerehabilitation alternative for people with diabetes to improve their self-monitoring and self-care management. This study assessed the feasibility, safety, acceptability, and changes in foot health and neuropathy symptoms in people with diabetes after 12 weeks of the intervention program with the Sistema de Orientação ao Pé diabético - Diabetic Foot Guidance System (SOPeD).

METHODS

Fourteen individuals were recruited and randomized to either the usual care (control group) or usual care plus an internet-based foot-ankle exercise program through SOPeD (intervention group) three times per week for 12 weeks. For feasibility, we assessed contact and recruitment rates per week; program adherence, determined as completing over 70% of the 36 sessions; and participant satisfaction and safety assessed through a questionnaire and scored on a 5-point Likert scale. We assessed changes in neuropathy symptoms and foot health and functionality from baseline to 12 weeks estimating differences or median of differences and 95% confidence intervals in the intervention group.

RESULTS

In 24 weeks, of the 822 patients in the database, 192 were contacted, 65 were assessed for eligibility, and 20 were considered eligible. The recruitment rate was 0.83 participants per week. Fourteen out of the 20 eligible participants agreed to participate, resulting in recruitment success of 70%. Adherence to the program was 66.7%, and there was no dropout. Participants' median level of satisfaction was 5.0 (IQR: 4.5-5.0) and perceived safety was 5.0 (IQR: 5.0-5.0).

CONCLUSION

The internet-based foot-ankle exercise program using SOPeD is feasible, satisfactory, and safe. Although this study had moderate adherence and a zero-dropout rate, recruitment needs to be improved in the larger trial.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04011267 . Registered on 8 July 2019.

Study protocol for a randomized controlled trial on the effect of the Diabetic Foot Guidance System (SOPeD) for the prevention and treatment of foot musculoskeletal dysfunctions in people with diabetic neuropathy: the FOotCAre (FOCA) trial I

BACKGROUND

This study is part of a series of two clinical trials. Taking into account the various musculoskeletal alterations of the foot and ankle in people with diabetic peripheral neuropathy (DPN) and the need for self-care to avoid more serious dysfunctions and complications, a self-manageable exercise protocol that focuses on strengthening the foot muscles is presented as a potentially effective preventive method for foot and gait complications. The aim of this trial is to investigate the effect of a customized rehabilitation technology, the Diabetic Foot Guidance System (SOPeD), on DPN status, functional outcomes and gait biomechanics in people with DPN.

METHODS/DESIGN

Footcare (FOCA) trial I is a randomized, controlled and parallel two-arm trial with blind assessment. A total of 62 patients with DPN will be allocated into either a control group (recommended foot care by international consensus with no foot exercises) or an intervention group (who will perform exercises through SOPeD at home three times a week for 12 weeks). The exercise program will be customized throughout its course by a perceived effort scale reported by the participant after completion of each exercise. The participants will be assessed at three different times (baseline, completion at 12 weeks, and follow-up at 24 weeks) for all outcomes. The primary outcomes will be DPN symptoms and severity classification. The secondary outcomes will be foot-ankle kinematics and kinetic and plantar pressure distribution during gait, tactile and vibration sensitivities, foot health and functionality, foot strength, and functional balance.

DISCUSSION

As there is no evidence about the efficacy of rehabilitation technology in reducing DPN symptoms and severity or improving biomechanical, clinical, and functional outcomes for people with DPN, this research can contribute substantially to clarifying the therapeutic merits of software interventions. We hope that the use of our application for people with DPN complications will reduce or attenuate the deficits caused by DPN. This rehabilitation technology is freely available, and we intend to introduce it into the public health system in Brazil after demonstrating its effectiveness.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04011267. Registered on 8 July 2019.

A study protocol on nerve mobilization induced diffusion tensor imaging values in posterior tibial nerve in healthy controls and in patients with diabetic neuropathy-multigroup pretest posttest design

Background

Diabetic neuropathy is the commonest chronic disabling complication of diabetes which may lead to amputation and compromising patient’s quality of life. It is characterized by pain, sensation loss associated with neural edema. Diffusion tensor imaging parameter i.e. fraction anisotropy determines the free water proton diffusion in the healthy nerve. Since the diabetes leads to altered mechanosensitivity of the posterior tibial nerve thereby, might interferes with the water molecules movement. Therefore the present clinical trial will provide the evidence of improving the diffusion tensor imaging in the diabetic neuropathy directly by targeting the nerve through nerve mobilization treatment.

Methods

Participants with Type II Diabetes Mellitus induced peripheral neuropathy will be selected randomly on the basis of eligibility criteria and informed consent will be taken. Participants will be recruited into three groups. Group A (experimental group A) will receive neural mobilization technique, Group B (experimental group B) will receive conventional therapy and Group C (control group) will receive sham treatment for 3 weeks. MRI technique, Visual analogue scale and neuropathy specific quality of life questionnaire will be used as assessment tools. Assessment will be taken at baseline and post intervention.

Conclusion

this clinical trial will provide the evidence of efficacy of nerve mobilization in determining the diffusion tensor imaging (DTI) changes in the posterior tibial nerve in patients with diabetic neuropathy. This trial will also be the first one in itself to look at the treatment induced DTI changes in the peripheral nerve.

Trial Registration

Clinical Trial Registry of India (CTRI/2019/06/019552).

Motor strategy patterns study of diabetic neuropathic individuals while walking. A wavelet approach

The aim of this study was to investigate muscle׳s energy patterns and spectral properties of diabetic neuropathic individuals during gait cycle using wavelet approach. Twenty-one diabetic patients diagnosed with peripheral neuropathy, and 21 non-diabetic individuals were assessed during the whole gait cycle. Activation patterns of vastus lateralis, medial gastrocnemius and tibialis anterior were studied by means of bipolar surface EMG. The signal׳s energy and frequency were compared between groups using t-test. The energy was compared in each frequency band (7-542 Hz) using ANOVAs for repeated measures for each group and each muscle. The diabetic individuals displayed lower energies in lower frequency bands for all muscles and higher energies in higher frequency bands for the extensors׳ muscles. They also showed lower total energy of gastrocnemius and a higher total energy of vastus, considering the whole gait cycle. The overall results suggest a change in the neuromuscular strategy of the main extensor muscles of the lower limb of diabetic patients to compensate the ankle extensor deficit to propel the body forward and accomplish the walking task.

Validation of plantar pressure measurements for a novel in-shoe plantar sensory replacement unit

An article by Ferber and coauthors in Journal of Diabetes Science and Technology reported on the ability of a novel in-shoe plantar sensory replacement unit (PSRU) to provide alert-based feedback derived from analyzing plantar pressure (PP) threshold measurements in real time. The study aimed at comparing the PSRU device to a gold standard pressure-sensing device (GS-PSD) to determine the correlation between concurrent measures of PP during walking. Data were collected simultaneously from 10 participants who walked overground with both devices. The variable of interest was the number of recorded data points greater than 32 mmHg for each of the PSRU sensors and corresponding average recordings from the GS-PSD. Authors concluded that the PSRU provides analogous data to the GS-PSD. However, several aspects of the study should be considered when interpreting their clinical relevance.

Integrated kinematics-kinetics-plantar pressure data analysis: a useful tool for characterizing diabetic foot biomechanics

The fundamental cause of lower-extremity complications in diabetes is chronic hyperglycemia leading to diabetic foot ulcer pathology. While the relationship between abnormal plantar pressure distribution and plantar ulcers has been widely investigated, little is known about the role of shear stress. Moreover, the mutual relationship among plantar pressure, shear stress, and abnormal kinematics in the etiology of diabetic foot has not been established. This lack of knowledge is determined by the lack of commercially available instruments which allow such a complex analysis. This study aims to develop a method for the simultaneous assessment of kinematics, kinetics, and plantar pressure on foot subareas of diabetic subjects by means of combining three commercial systems. Data were collected during gait on 24 patients (12 controls and 12 diabetic neuropathics) with a motion capture system synchronized with two force plates and two baropodometric systems. A four segment three-dimensional foot kinematics model was adopted for the subsegment angles estimation together with a three segment model for the plantar sub-area definition during gait. The neuropathic group exhibited significantly excessive plantar pressure, ground reaction forces on each direction, and a reduced loading surface on the midfoot subsegment (p<0.04). Furthermore the same subsegment displayed excessive dorsiflexion, external rotation, and eversion (p<0.05). Initial results showed that this methodology may enable a more appropriate characterization of patients at risk of foot ulcerations, and help planning prevention programs.

A moderate-intensity weight-bearing exercise program for a person with type 2 diabetes and peripheral neuropathy

BACKGROUND AND PURPOSE

The exercise guidelines for people with diabetes mellitus and peripheral neuropathy (DM+PN) have recently changed to allow moderate-intensity weight-bearing exercise, but there are few reports in the literature describing appropriate weight-bearing exercise for those with DM+PN. This case report describes a successful and safe progressive exercise program for an individual with DM+PN.

CASE DESCRIPTION

The patient was a 76-year-old man with a 30-year history of DM+PN. He participated in a 12-week, moderate-intensity, progressive exercise program (heart rate approximately 75% of maximum heart rate; rate of perceived exertion=11-13; 3 times per week) involving walking on a treadmill, balance exercises, and strengthening exercises for the lower extremities using body weight resistance.

OUTCOMES

Measurements were taken before and after the 12 weeks of exercise. The patient's Six-Minute Walk Test distance increased from 1,200 to 1,470 ft. His Physical Performance Test score did not change. His Foot and Ankle Ability Measure questionnaire score improved from 89 to 98. Dorsiflexor and plantar-flexor peak torque increased (dorsiflexor peak torque: right side=4.5-4.6 N·m, left side=2.8-3.8 N·m; plantar-flexor peak torque: right side=44.7-62.4 N·m, left side=40.8-56.0 N·m), as did his average daily step count (6,176-8,273 steps/day). Close monitoring of the plantar surface of the feet indicated that the exercise program was well tolerated and there were no adverse events.

DISCUSSION AND CONCLUSION

This case report describes a moderate-intensity exercise program that was successful in increasing some measures of muscle strength, physical function, and activity without causing injury in an individual with DM+PN.

A new device for assessing ankle dorsiflexion motion: reliability and validity

STUDY DESIGN

Clinical measurement.

OBJECTIVE

To determine the validity and reliability of measures obtained using a custom-made device for assessing ankle dorsiflexion motion and stiffness.

BACKGROUND

Limited dorsiflexion has been implicated in the evolution of foot pain in a number of clinical populations. Assessment of ankle dorsiflexion range of motion (ROM) is, therefore, commonly performed as part of a foot and ankle examination. Conventional goniometric assessment methods have demonstrated limited intertester reliability, while alternative methods of measurements are generally more difficult to use. The Iowa ankle range of motion (IAROM) device was designed in an attempt to develop a simple, clinically relevant, and time- and cost-effective tool to measure ankle dorsiflexion range of motion and stiffness.

METHODS

Validity and intertester reliability of dorsiflexion range-of-motion measures using the IAROM device were assessed at 10, 15, 20, and 25 Nm of passively applied dorsiflexion torque, with both the knee extended and flexed approximately 20°. Stiffness (change in torque/change in dorsiflexion angle) values were determined using the angular change obtained between the 15- and 25-Nm torque levels. Convergent validity (n = 12) was assessed through comparison of ankle dorsiflexion angles measured simultaneously with the IAROM device and an optoelectronic motion analysis system. Intertester reliability (n = 17) was assessed by 2 testers who took measurements within the same day.

RESULTS

Validity testing demonstrated excellent agreement (intraclass correlation coefficient [ICC] values ranging from 0.95 to 0.98). Reliability testing demonstrated good to excellent intertester agreement (ICC values ranging from 0.90 to 0.95). The ICCs for ankle joint dorsiflexion stiffness were .71 and .85 for the knee in an extended and flexed position, respectively.

CONCLUSION

The IAROM device provides valid and reliable measurement of ankle dorsiflexion ROM. The IAROM device also allows calculation of stiffness by measuring ROM at multiple torque levels, although the reliability of the measurement is not optimal.

Limited joint mobility (LJM) in elderly subjects with type II diabetes mellitus

LJM is frequently observed in young subjects with insulin-dependent diabetes mellitus (IDDM). Aim of this study was to evaluate whether non-insulin-dependent diabetes mellitus (NIDDM) increases the risk of LJM in elderly subjects. Thirty patients (15 males, 15 females, mean age 73.93 ± 12.72 years) with NIDDM in good glycemic control were compared with thirty non-diabetic elderly, well matched for sex and age (15 males, 15 females, mean age 74.3 ± 4.24 years), and with ten young normal subjects (5 males, 5 females, mean age 26.3 ± 1.56 years). In these subjects, the range of motion (ROM) of ankle, knee, hip, elbow and shoulder were measured with a double-armed goniometer. Moreover, abnormalities of supraspinatus, patellar and Achilles tendons were evaluated with a standardized ultrasound (US) procedure. A significant reduction in the mobility of all joints was found in elderly subjects, compared to younger ones, with exception for the knee and elbow flexion. Elderly patients with diabetes, compared with their age-matched counterpart, showed LJM for ankle dorso- and plantar flexion, hip flexion and adduction, shoulder abduction and flexion. Moreover, tendons sonographic abnormalities were more frequently observed in diabetics. Our data confirm that diabetes worsens the LJM in the elderly, increasing the cross-linking of collagen by the non-enzymatic advanced glycation end products formation.

Diabetic foot biomechanics and gait dysfunction

BACKGROUND

Diabetic foot complications represent significant morbidity and precede most of the lower extremity amputations performed. Peripheral neuropathy is a frequent complication of diabetes shown to affect gait. Glycosylation of soft tissues can also affect gait. The purpose of this review article is to highlight the changes in gait for persons with diabetes and highlight the effects of glycosylation on soft tissues at the foot-ground interface.

METHODS

PubMed, the Cochrane Library, and EBSCOhost on-line databases were searched for articles pertaining to diabetes and gait. Bibliographies from relevant manuscripts were also searched.

FINDINGS

Patients with diabetes frequently exhibit a conservative gait strategy where there is slower walking speed, wider base of gait, and prolonged double support time. Glycosylation affects are observed in the lower extremities. Initially, skin thickness decreases and skin hardness increases; tendons thicken; muscles atrophy and exhibit activation delays; bones become less dense; joints have limited mobility; and fat pads are less thick, demonstrate fibrotic atrophy, migrate distally, and may be stiffer.

INTERPRETATION

In conclusion, there do appear to be gait changes in patients with diabetes. These changes, coupled with local soft tissue changes from advanced glycosylated end products, also alter a patient's gait, putting them at risk of foot ulceration. Better elucidation of these changes throughout the entire spectrum of diabetes disease can help design better treatments and potentially reduce the unnecessarily high prevalence of foot ulcers and amputation.

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.

Muscle weakness: a progressive late complication in diabetic distal symmetric polyneuropathy

The aim of the study was to determine the progression of muscle weakness in long-term diabetes and its relation to the neuropathic condition. Thirty patients were recruited from a cohort of 92 diabetic patients who participated in a study on muscular function 6-8 years earlier. Nine subjects were nonneuropathic, 9 had asymptomatic neuropathy, and 12 had symptomatic neuropathy. Thirty matched control subjects who participated in the initial studies were also included. At follow-up, isokinetic dynamometry at the ankle, electrophysiological studies, vibratory perception thresholds, and clinical examination (neuropathy symptom score and neurological disability score [NDS]) were repeated. The annual decline of strength at the ankle was 0.7 +/- 1.7% in control subjects, 0.9 +/- 1.9% in nonneuropathic patients, 0.7 +/- 3.1% in asymptomatic neuropathic patients, and 3.2 +/- 2.3% in symptomatic neuropathic patients. In the symptomatic patients, the decline of muscle strength at the ankle was significant when compared with matched control subjects (P = 0.002) and with the other diabetic groups (P = 0.023). Also, the annual decline of muscle strength at the ankle was related to the combined score of all measures of neuropathy (r = -0.42, P = 0.03) and to the NDS (r = -0.52, P = 0.01). In patients with symptomatic diabetic neuropathy, weakness of ankle plantar and dorsal flexors is progressive and related to the severity of neuropathy.

Effects of an eight-week stretching program on the passive-elastic properties and function of the calf muscles of older women

BACKGROUND

Calf muscle stretching programs are used to increase dorsiflexion range of motion at the ankle, yet the effects of the stretching programs on the passive properties of aged calf muscles and on standing and ambulatory function have not been studied. This initial study examined the effects of an eight-week stretching program on the passive-elastic properties of the calf muscles of older women and on selected functional activities.

METHODS

Nineteen women aged 65-89 years with limited dorsiflexion range of motion first completed a timed agility course, a timed 10-m walk and a standing functional reach test. A dynamometer then moved the right ankle from plantarflexion to maximal dorsiflexion and back to plantarflexion at 5 deg s(-1) to measure calf muscle passive properties. The women were randomly assigned to a group that stretched three-times a week for eight-weeks (n=10) or to a control group (n=9) that did not. The tests were repeated after the stretching program.

FINDINGS

The stretching group showed increased maximal dorsiflexion range of motion, passive resistive forces (Newtons [N]), and the absorbed and retained passive-elastic energy (deg N) (P<0.05). They also had decreased times for the agility course and the 10-m walk (P<0.05). The functional reach test did not change for either group.

INTERPRETATION

The eight-week stretching program most likely increased the maximal length, length extensibility and passive resistive forces of the calf muscles. Adaptations of other ankle and leg structures also may have contributed. The passive adaptations were associated with enhanced performances of ambulatory functional activities.

Implementing a clinical assessment protocol for sensory and skeletal function in diabetic neuropathy patients at a university hospital in Brazil

CONTEXT AND OBJECTIVE

Physiotherapy can contribute towards recovering or preventing physical and sensory alterations in diabetic neuropathy patients. Our objective was to create and apply a protocol for functional assessment of diabetic neuropathy patients' lower limbs, to guide future physiotherapy.

DESIGN AND SETTING

Clinical study at the University Hospital and teaching/research center of Universidade de São Paulo.

METHODS

An intentional sample of diabetic neuropathy patients was utilized. The protocol was divided into: (1) preliminary investigation with identification of relevant clinical diabetes and neuropathy characteristics; (2) thermal, tactile and proprioceptive sensitivity tests on the feet; (3) evaluations of muscle function, range of motion, lower limb function, foot anthropometry.

RESULTS

The patients' mean age was 57 years, and they had had the diagnosis for 13 years on average. Distal numbness and tingling/prickling were present in 62% and 67%, respectively. There were tactile sensitivity alterations above the heel in 50%, with thermal sensitivity in 40% to 60%. The worst muscle function test responses were at the triceps surae and foot intrinsic muscles. Longitudinal plantar arches were lowered in 50%. Decreased thermal and tactile sensitivity of the heels was found. There was a general reduction in range of motion.

CONCLUSIONS

The results provided detailed characterization of the patients. This protocol may be easily applied in healthcare services, since it requires little equipment, at low cost, and it is well understood by patients.

Does the thickening of Achilles tendon and plantar fascia contribute to the alteration of diabetic foot loading?

BACKGROUND

The diabetic foot often undergoes abnormal plantar pressures, changing in walking strategy, ulcerative processes. The present study focuses on the effects that diabetes-induced alterations of Achilles tendon, plantar fascia and first metatarso-phalangeal joint-both anatomical and functional-may have on foot loading.

METHODS

Sixty-one diabetic patients, with or without neuropathy, and 21 healthy volunteers were recruited. Thickness of Achilles tendon and plantar fascia was measured by ultrasound. Flexion-extension of the first metatarso-phalangeal joint was measured passively. Main biomechanic parameters of foot-floor interaction during gait were acquired and related to the above measurements.

FINDINGS

Plantar fascia and Achilles tendon were significantly (P<0.05) thicker in diabetics than in controls; mean values (SD) for controls, diabetics without and with neuropathy were 2.0 mm (0.5), 2.9 mm (1.2) and 3.0 mm (0.8) for plantar fascia, respectively, and 4.0 mm (0.5), 4.6 mm (1.0) and 4.9 mm (1.7) for Achilles tendon, respectively. Flexion-extension of the first metatarso-phalangeal joint was significantly (P<0.05) smaller in diabetics than in controls; mean values (SD) for controls, diabetics without and with neuropathy were 100.0 degrees (10.0), 54.0 degrees (29.4) and 54.9 degrees (17.2), respectively. The increase in the vertical force under the metatarsals was strongly related (R=0.83, explained variance=70.1%) to the changes in the three above parameters.

INTERPRETATION

Thickening of plantar fascia and Achilles tendon in diabetics, more evident in the presence of neuropathy, concurs to develop a rigid foot, which poorly absorbs shock during landing (performs the physiological impact force absorption during landing). More generally, an overall alteration of the foot-ankle complex motion likely occurs throughout the whole gait cycle, which partly explains the abnormal loading under the forefoot.

Slow passive stretch and release characteristics of the calf muscles of older women with limited dorsiflexion range of motion

OBJECTIVE

Examine the slow passive stretch and release characteristics of the calf muscles of older women with limited dorsiflexion range of motion.

DESIGN

A cross-sectional comparative design.

BACKGROUND

The passive stretch and release characteristics of the calf muscles of older women with limited dorsiflexion range of motion have not been studied.

METHODS

Fifteen older women (mean 79 years) with active dorsiflexion < or =10 degrees and 15 younger women (mean 24 years) without limited dorsiflexion were tested. The right ankle was stretched from plantarflexion to maximal dorsiflexion and released into plantarflexion at 5 degrees /s with minimal surface EMG activity in the soleus, gastrocnemius, and tibialis anterior muscles. Length, passive-elastic stiffness and stored passive-elastic energy were examined.

RESULTS

The older women had less maximal passive dorsiflexion, a greater initial stretch angle, and less angular change than the younger women (P < 0.05). The maximal passive resistive force (Newtons) of the stretch phase, and the stored passive-elastic energy ( degrees N) during both stretch and release phases were also less (P < 0.001). The older women had greater passive-elastic stiffness at 0 degrees and 5 degrees of dorsiflexion (P < 0.001).

CONCLUSIONS

The older women had decreased calf muscle length, extensibility, maximal passive resistive force, stored passive-elastic energy, but greater angle-specific-stiffness at 0 and 5 degrees of passive dorsiflexion.

RELEVANCE

Older women with limited dorsiflexion range of motion have decreased calf muscle length, passive resistive forces and stored passive-elastic energy that may impact static and dynamic standing balance activities. Greater passive-elastic stiffness within their ambulatory dorsiflexion range of motion may partially compensate for the deficits.

Effect of plantar flexor muscle stiffness on selected gait characteristics

Although plantar flexor muscle strength is known to affect gait characteristics, the effect of plantar flexor (PF) muscle stiffness on gait is unknown. The purpose of this study was to determine the effect of PF muscle stiffness, in addition to PF strength, on the gait characteristics of subjects with diabetes and peripheral neuropathy (DM & PN) and age-matched controls. Thirty-four subjects were tested (17 DM & PN, 17 controls), 10 males and seven females in each group. PF muscle strength (concentric peak torque) explained a significant amount of variance in all gait variables (20-37%). Passive stiffness added a unique contribution to plantar flexor peak moment and walking speed (10-11%). Plantar flexor stiffness, in addition to strength, may be an important factor contributing to gait characteristics. Treatment techniques designed to preserve or increase stiffness may be indicated for patients with limited PF strength.