Effects of strengthening, stretching and functional training on foot function in patients with diabetic neuropathy: results of a randomized controlled trial.

BACKGROUND: Foot musculoskeletal deficits are seldom addressed by preventive medicine despite their high prevalence in patients with diabetic polyneuropathy. AIM: To investigate the effects of strengthening, stretching, and functional training on foot rollover process during gait. METHODS: A two-arm parallel-group randomized controlled trial with a blinded assessor was designed. Fifty-five patients diagnosed with diabetic polyneuropathy, 45 to 65 years-old were recruited. Exercises for foot-ankle and gait training were administered twice a week, for 12 weeks, to 26 patients assigned to the intervention group, while 29 patients assigned to control group received recommended standard medical care: pharmacological treatment for diabetes and foot care instructions. Both groups were assessed after 12 weeks, and the intervention group at follow-up (24 weeks). Primary outcomes involved foot rollover changes during gait, including peak pressure (PP). Secondary outcomes involved time-to-peak pressure (TPP) and pressure-time integral (PTI) in six foot-areas, mean center of pressure (COP) velocity, ankle kinematics and kinetics in the sagittal plane, intrinsic and extrinsic muscle function, and functional tests of foot and ankle. RESULTS: Even though the intervention group primary outcome (PP) showed a not statistically significant change under the six foot areas, intention-to-treat comparisons yielded softening of heel strike (delayed heel TPP, p=.03), better eccentric control of forefoot contact (decrease in ankle extensor moment, p<.01; increase in function of ankle dorsiflexion, p<.05), earlier lateral forefoot contact with respect to medial forefoot (TPP anticipation, p<.01), and increased participation of hallux (increased PP and PTI, p=.03) and toes (increase in PTI, medium effect size). A slower COP mean velocity (p=.05), and an increase in overall foot and ankle function (p<.05) were also observed. In most cases, the values returned to baseline after the follow-up (p<.05). CONCLUSIONS: Intervention discreetly changed foot rollover towards a more physiological process, supported by improved plantar pressure distribution and better functional condition of the foot ankle complex. Continuous monitoring of the foot status and patient education are necessary, and can contribute to preserving the integrity of foot muscles and joints impaired by polyneuropathy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01207284, registered in 20th September 2010.

Effect of diabetic neuropathy severity classified by a fuzzy model in muscle dynamics during gait.

BACKGROUND: Electromyography (EMG) alterations during gait, supposedly caused by diabetic sensorimotor polyneuropathy, are subtle and still inconsistent, due to difficulties in defining homogeneous experimental groups with a clear definition of disease stages. Since evaluating these patients involve many uncertainties, the use of a fuzzy model could enable a better discrimination among different stages of diabetic polyneuropathy and lead to a clarification of when changes in muscle activation start occurring. The aim of this study was to investigate EMG patterns during gait in diabetic individuals with different stages of DSP severity, classified by a fuzzy system. METHODS: 147 subjects were divided into a control group (n = 30) and four diabetic groups: absent (n = 43), mild (n = 30), moderate (n = 16), and severe (n = 28) neuropathy, classified by a fuzzy model. The EMG activity of the vastus lateralis, tibialis anterior, and gastrocnemius medialis were measured during gait. Temporal and relative magnitude variables were compared among groups using ANOVA tests. RESULTS: Muscle activity changes are present even before an established neural involvement, with delay in vastus lateralis peak and lower tibialis anterior relative magnitude. These alterations suggest an impaired ankle shock absorption mechanism, with compensation at the knee. This condition seems to be more pronounced in higher degrees of neuropathy, as there is an increased vastus lateralis activity in the mild and severe neuropathy groups. Tibialis anterior onset at terminal stance was anticipated in all diabetic groups; at higher degrees of neuropathy, the gastrocnemius medialis exhibited activity reduction and peak delay. CONCLUSION: EMG alterations in the vastus lateralis and tibialis anterior occur even in the absence of diabetic neuropathy and in mild neuropathic subjects, seemingly causing changes in the shock absorption mechanisms at the heel strike. These changes increase with the onset of neural impairments, and the gastrocnemius medialis starts presenting altered activity in the later stages of the disease (moderate and severe neuropathy). The degree of severity of diabetic neuropathy must be taken into account when analyzing diabetic patients' biomechanical patterns of locomotion; we recommend the use of a fuzzy model for classification of disease stages.

Long-term use of minimal footwear on pain, self-reported function, analgesic intake, and joint loading in elderly women with knee osteoarthritis: A randomized controlled trial.

BACKGROUND: Efforts have been made to retard the progressive debilitating pain and joint dysfunction in patients with knee osteoarthritis. We aimed to evaluate the therapeutic effect of a low-cost minimalist footwear on pain, function, clinical and gait-biomechanical aspects of elderly women with knee osteoarthritis. METHODS: Throughout a randomized, parallel and controlled clinical trial, fifty-six patients with medial knee osteoarthritis were randomly allocated to an intervention (n=28) or control group (n=28), and assessed at baseline and after three and six months. The intervention involved wearing Moleca(®) footwear for at least 6h/day, 7 days/week, over 6 months. The pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index was the primary outcome. The secondary outcomes were the other subscales, Lequesne score, distance walked in 6 min, knee oedema and effusion, knee adduction moment and paracetamol intake. Intention-to-treat analysis was performed using two-way casewise ANOVA (< .05) and Cohen's d coefficient. FINDINGS: Intervention group showed improvement in pain (effect size: 1.41, p<.001), function (effect size: 1.22, p=.001), stiffness (effect size: 0.76, p=.001), Lequesne score (effect size: 1.07, p<.001), and reduction by 21.8% in the knee adduction moment impulse (p=.017) during gait wearing Moleca(®). The analgesic intake was lower in the intervention group. INTERPRETATION: The long-term use of Moleca(®) footwear relieves pain, improves self-reported function, reduces the knee loading while wearing Moleca(®), refrains the increase of analgesic intake in elderly women with knee osteoarthritis and can be considered as a conservative mechanical treatment option. ClinicalTrials.gov (NCT01342458).

Biomechanical variables and perception of comfort in running shoes with different cushioning technologies.

OBJECTIVES: To investigate the relationships between the perception of comfort and biomechanical parameters (plantar pressure and ground reaction force) during running with four different types of cushioning technology in running shoes. DESIGN: Randomized repeated measures. METHODS: Twenty-two men, recreational runners (18-45 years) ran 12km/h with running shoes with four different cushioning systems. Outcome measures included nine items related to perception of comfort and 12 biomechanical measures related to the ground reaction forces and plantar pressures. Repeated measure ANOVAs, Pearson correlation coefficients, and step-wise multiple regression analyses were employed (p≤0.05). RESULTS: No significant correlations were found between the perception of comfort and the biomechanical parameters for the four types of investigated shoes. Regression analysis revealed that 56% of the perceived general comfort can be explained by the variables push-off rate and pressure integral over the forefoot (p=0.015) and that 33% of the perception of comfort over the forefoot can be explained by second peak force and push-off rate (p=0.016). CONCLUSIONS: The results did not demonstrate significant relationships between the perception of comfort and the biomechanical parameters for the three types of shoes investigated (Gel, Air, and ethylene-vinyl acetate). Only the shoe with Adiprene+ technology had its general comfort and cushioning perception predicted by the loads over the forefoot. Thus, in general, one cannot predict the perception of comfort of a running shoe through impact and plantar pressure received.

Multichannel EMG-based estimation of fiber conduction velocity during isometric contraction of patients with different stages of diabetic neuropathy.

This study compares muscle fiber conduction velocities estimated using surface electromyography during isometric maximal voluntary contraction in different stages of diabetic neuropathy. Eighty-five adults were studied: 16 non-diabetic individuals and 69 diabetic patients classified into four neuropathy stages, defined by a fuzzy expert system: absent (n=26), mild (n=21), moderate (n=11) and severe (n=11). Average muscle fiber conduction velocities of gastrocnemius medialis, tibialis anterior, vastus lateralis and biceps femoris were assessed using linear array electrodes, and were compared by ANOVA. Conduction velocities were significantly decreased in the moderate neuropathy group for the vastus lateralis compared to other groups (from 18% to 21% decrease), and were also decreased in all diabetic groups for the tibialis anterior (from 15% to 20% from control group). Not only the distal anatomical localization of the muscle affects the conduction velocity, but also the proportion of muscle fiber type, where the tibialis anterior with greater type I fiber proportion is affected earlier while the vastus lateralis with greater type II fiber proportion is affected in later stages of the disease. Generally, the muscles of the lower limb have different responsiveness to the effects of diabetes mellitus and show a reduction in the conduction velocity as neuropathy progresses.