Upper extremity impairments, pain and disability in patients with diabetes mellitus.

OBJECTIVES: To determine the severity of, and relationships between, upper extremity impairments, pain and disability in patients with diabetes mellitus, and to compare upper extremity impairments in patients with diabetes with non-diabetic controls. DESIGN: Case-control, cross-sectional design. SETTING: University-based, outpatient diabetes centre and physical therapy research clinic. PARTICIPANTS: Two hundred and thirty-six patients with diabetes attending an outpatient diabetes clinic completed the Shoulder Pain and Disability Index (SPADI) questionnaire. A detailed shoulder and hand examination was conducted on a subgroup of 29 volunteers with type 2 diabetes, and 27 controls matched for age, sex and body mass index. INTERVENTIONS: None. MAIN OUTCOME MEASURES: SPADI score, passive shoulder range of motion (ROM) and strength, grip strength, hand sensation, dexterity and limited joint mobility of the hand. RESULTS: Sixty-three percent (149/236) of patients with diabetes reported shoulder pain and/or disability [median SPADI score 10.0 (interquartile range 0.0 to 39.6)]. Compared with the control group, the subgroup of patients with diabetes had substantial reductions in shoulder ROM, shoulder muscle strength, grip and key pinch strength (P<0.05). Patients with diabetes had a greater prevalence of decreased sensation (26/27 vs 14/27) and limited joint mobility of the hand (17/27 vs 4/27) compared with the control group. Total SPADI score was negatively correlated (P<0.05) with shoulder ROM (r=-0.42 to -0.74) and strength measures (r=-0.44 to -0.63) in patients with diabetes. CONCLUSIONS: Upper extremity impairments in this sample of patients with diabetes were common, severe and related to complaints of pain and disability. Additional research is needed to understand the unique reasons for upper extremity problems in patients with diabetes, and to identify preventative treatments.

Pollen-derived low-molecular weight factors inhibit 6-sulfo LacNAc+ dendritic cells' capacity to induce T-helper type 1 responses.

BACKGROUND: Evidence is accumulating that the pollen exsudate contains an array of non-allergenic, pro-inflammatory and immunomodulatory substances acting on the innate and adaptive immune system. In this context, pollen-associated E(1)-phytoprostanes (PPE(1)) were shown to licence human monocyte-derived dendritic cells for T-helper type 2 (Th2) polarization of naïve T cells. OBJECTIVE: This study aims at analysing the impact of pollen-associated lipid mediators on cytokine secretion and maturation of 6-sulfo LacNAc(+) dendritic cells (slanDCs), the most abundant native dendritic cell (DC) in human peripheral blood, and further dissecting the biologically active substance(s) within aqueous pollen extracts. RESULTS: Aqueous birch pollen extracts dose-dependently inhibited the lipopolysaccharide (LPS)-induced IL-12 p70 production, while the levels of IL-6 remained unaffected. PPE(1) inhibited secretion of both IL-12 p70 and IL-6. Aqueous pollen extracts, but not PPE(1) or F(1)-phytoprostanes significantly reduced the LPS-induced surface expression of the maturation markers CD80, CD83, CD40 and CCR-7, an effect that was independent of proteins and that was still present in a 3 kDa cut-off fraction of the pollen extract. These effects were observed irrespective of the atopy status of the donors. Finally, slanDCs exposed to aqueous pollen extracts were impaired in eliciting an IFN-gamma response in naïve CD4(+) T cells. CONCLUSION: Our data show that slanDCs, a subset of human blood DCs with constitutively high potency to induce Th1 responses, are susceptible to the Th2 polarizing effect of low molecular weight, non-protein factors derived from pollen.

Muscle imbalance and reduced ankle joint motion in people with hammer toe deformity.

BACKGROUND: Multiple factors may contribute to hammer toe deformity at the metatarsophalangeal joint. The purposes of this study were to (1) compare the ratio of toe extensor/flexor muscle strength in toes 2-4 among groups with and without hammer toe deformity, (2) to determine correlations between the ratio of toe extensor/flexor muscle strength in toes 2-4, and metatarsophalangeal joint deformity (3) to determine if other clinical measures differ between groups and if these measures are correlated with metatarsophalangeal joint angle. METHODS: Twenty-seven feet with visible hammer toe deformity and 31 age matched feet without hammer toe deformity were tested. Toe muscle strength was measured using a dynamometer and the ratio of toe extensor muscle strength to flexor muscle strength was calculated. Metatarsophalangeal joint angle was measured from a computerized tomography image. Ankle and subtalar joint range of motion, and tibial torsion were measured using goniometry. FINDINGS: Extensor/flexor toe muscle strength ratio was 2.3-3.0 times higher in the hammer toe group compared to the non-hammer toe group, in toes 2-4. The ratios of extensor/flexor toe muscle strength for toes 2-4 and metatarsophalangeal joint angle were highly correlated (r=0.69-0.80). Ankle dorsiflexion and metatarsophalangeal joint angle were negatively correlated for toes 2-4 (r=-0.38 to -0.56) as were eversion and metatarsophalangeal joint angle. INTERPRETATION: These results provide insight into potential risk factors for the development of hammer toe deformity. Additional research is needed to determine the causal relationship between hammer toe deformity and the ratio of toe extensor/flexor muscle strength in toes 2-4.

Energy expenditure and energy intake - Guidelines on Parenteral Nutrition, Chapter 3.

The energy expenditure (24h total energy expenditure, TEE) of a healthy individual or a patient is a vital reference point for nutritional therapy to maintain body mass. TEE is usually determined by measuring resting energy expenditure (REE) by indirect calorimetry or by estimation with the help of formulae like the formula of Harris and Benedict with an accuracy of +/-20%. Further components of TEE (PAL, DIT) are estimated afterwards. TEE in intensive care patients is generally only 0-7% higher than REE, due to a low PAL and lower DIT. While diseases, like particularly sepsis, trauma and burns, cause a clinically relevant increase in REE between 40-80%, in many diseases, TEE is not markedly different from REE. A standard formula should not be used in critically ill patients, since energy expenditure changes depending on the course and the severity of disease. A clinical deterioration due to shock, severe sepsis or septic shock may lead to a drop of REE to a level only slightly (20%) above the normal REE of a healthy subject. Predominantly immobile patients should receive an energy intake between 1.0-1.2 times the determined REE, while immobile malnourished patients should receive a stepwise increased intake of 1.1-1.3 times the REE over a longer period. Critically ill patients in the acute stage of disease should be supplied equal or lower to the current TEE, energy intake should be increased stepwise up to 1.2 times (or up to 1.5 times in malnourished patients) thereafter.

Reliability and validity of measures of hammer toe deformity angle and tibial torsion.

BACKGROUND: Measures of second-fourth metatarsophalangeal joint (MTPJ) angle (indicator of hammer toe deformity) and clinical measures of tibial torsion have limited evidence for validity and reliability. The purposes of this study are to determine: (1) reliability of using a 3D digitizer (Metrecom) and computed tomography (CT) to measure MTPJ angle for toes 2-4; (2) reliability of goniometer, 3D digitizer, and CT to measure tibial torsion; (3) validity of MTPJ angle measures for toes 2-4 using goniometry and 3D digitizer compared to CT (gold standard) and (4) validity of tibial torsion measures using goniometry and 3D digitizer (Metrecom) compared to CT (gold standard). METHODS: Twenty-nine subjects participated in this study. 27 feet with hammer toe deformity and 31 feet without hammer toe deformity were tested using standardized gonimetric, 3D digitizer and CT methods. ICCs (3,1), standard error of the measurement (SEM) values, and difference measures were used to characterize intrarater reliability. Pearson correlation coefficients and an analysis of variance were used to determine associations and differences between the measurement techniques. FINDINGS: 3D digitizer and CT measures of MTPJ angle had high test-retest reliability (ICC = 0.95-0.96 and 0.98-0.99, respectively; SEM = 2.64-3.35 degrees and 1.42-1.47 degrees, respectively). Goniometry, 3D digitizer, and CT measures of tibial torsion had good test-retest reliability (ICC = 0.75, 0.85, and 0.98, respectively; SEM = 2.15 degrees, 1.74 degrees, and 0.72 degree, respectively). Both goniometric and 3D digitizer measures of MTPJ angle were highly correlated with CT measures of MTPJ angle (r = 0.84-0.90, r = 0.84-0.88, respectively) and tibial torsion (r = 0.72, r = 0.83). Goniometry, 3D digitizer, and CT measures were all different from each other for measures of hammer toe deformity (p < 0.001). Goniometry measures were different from CT measures and 3D digitizer measures of tibial torsion (p < 0.002). CT measures and 3D digitizer measures of tibial torsion were similar (p = 0.112). INTERPRETATIONS: These results suggest that 3D digitizer and CT scan measures of MTPJ angle and goniometric, 3D digitizer, and CT scan measures of tibial torsion are reliable. Goniometer and 3D digitizer measures of MTPJ angle and tibial torsion measures are highly correlated with the gold standard CT method indicating good validity of measures, but the measures are not interchangeable.

Response of neutron detectors to high-energy mixed radiation fields.

Radiation protection around CERN's high-energy accelerators represents a major challenge due to the presence of complex, mixed radiation fields. Behind thick shielding neutrons dominate and their energy ranges from fractions of eV to about 1 GeV. In this work the response of various portable detectors sensitive to neutrons was studied at CERN's High-Energy Reference Field Facility (CERF). The measurements were carried out with conventional rem counters, which usually cover neutron energies up to 20 MeV, the Thermo WENDI-2, which is specified to measure neutrons up to several GeV, and a tissue-equivalent proportional counter. The experimentally determined neutron dose equivalent results were compared with Monte Carlo (MC) simulations. Based on these studies field calibration factors can be determined, which result in a more reliable estimate of H*(10) in an unknown, but presumably similar high-energy field around an accelerator than a calibration factor determined in a radiation field of a reference neutron source.

Tendon Achilles lengthening for the treatment of neuropathic ulcers causes a temporary reduction in forefoot pressure associated with changes in plantar flexor power rather than ankle motion during gait.

The purposes of this study were to determine the effects of tendon Achilles lengthening (TAL) on ambulatory plantar pressures and ankle range of motion, moment, and power, and to determine whether changes in forefoot pressure after treatment of a neuropathic ulcer are related to changes in ankle dorsiflexion range of motion (DFROM) or plantar flexor (PF) power during gait. Pressure and gait tests were performed before treatment, and at 3 weeks and 8 months after treatment in two randomly assigned groups of subjects with diabetes, equinus deformity, and a neuropathic forefoot ulcer treated with TAL and total contact casting (TAL group, n=14), or total contact casting alone (TCC group, n=14). The TAL group had an initial decrease in forefoot peak pressure (PP) (27%), forefoot pressure-time integral (PTI) (42%), PF moment (53%), and PF power (65%), along with an initial increase in rear foot PP (34%), rear foot PTI (48%), and DFROM (74%). Post-surgical changes in rear foot pressure and DFROM were maintained up to 8 months after treatment with TAL, whereas forefoot pressure and PF moment and power increased significantly. Changes in forefoot pressure after treatment in either group were correlated with changes in PF power (r=0.45-0.60), but not with changes in DFROM during gait (r=-0.02-0.08). Results suggest TAL causes a temporary reduction in forefoot pressure primarily by reducing PF power during gait. The initial decrease in forefoot pressure, followed by progressive reloading of forefoot tissues as PF muscles regain strength after TAL, may help reduce the risk of ulcer recurrence in patients with diabetes.

Novel Award 2002. Comparison of physical activity and cumulative plantar tissue stress among subjects with and without diabetes mellitus and a history of recurrent plantar ulcers.

OBJECTIVES: To compare the amount of weight-bearing activity and estimates of cumulative plantar tissue stress between subjects with and without diabetes mellitus and a history of recurrent plantar ulcers. DESIGN: Cross-sectional study with matched groups. BACKGROUND: Weight-bearing activity among individuals with diabetes is likely to influence the amount of mechanical trauma accumulated by plantar tissues, yet activity levels have not been accounted for in previous measurements of plantar tissue stress or predictions of plantar tissue injury. METHODS: Study groups included subjects with diabetes mellitus and peripheral neuropathy, either with or without a history of recurrent plantar ulcers, and non-diabetic control subjects (n=10 per group). Pressure on the plantar foot was assessed as subjects walked at their preferred speed in the shoes they reported wearing most often each day. Physical activity was monitored over seven consecutive days using an accelerometer. The product of mean daily strides and forefoot pressure-time integral was used to estimate daily cumulative stress on the plantar forefoot. RESULTS: Subjects with diabetes and a history of recurrent plantar ulcers were 46% less active than subjects without diabetes (mean (SD)=2727 (1345) versus 5037 (2624) strides/day, P=0.04), and accumulated 41% less daily stress on the forefoot than non-diabetic and diabetic control subjects without a history of plantar ulcers (mean (SD)= 210 (134) versus 354 (118) and 354 (148) MPas/day respectively, P=0.03). CONCLUSIONS: Subjects with diabetes and a history a previous ulcers may be susceptible to plantar tissue injury even at relatively low levels of cumulative tissue stress. RELEVANCE: Changes in weight-bearing activity following plantar tissue injury in patients with diabetes may influence plantar tissue adaptation and the risk of ulcer recurrence.

Monitoring in-shoe plantar pressures, temperature, and humidity: reliability and validity of measures from a portable device.

OBJECTIVE: To investigate the reliability and validity of measures obtained from a portable electronic device used to monitor changes in plantar pressure, temperature, and humidity that occur within the shoe during prolonged activity. DESIGN: Descriptive study comparing electronic sensor output with criterion values. SETTINGS: Indoor level walkway for pressure data; uncontrolled, outdoor environment for step count data; enclosed environmental control chamber for humidity and temperature data. PARTICIPANTS: Convenience sample of 4 healthy, sensate subjects. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Correlations between sensor output and criterion measures were determined for pressure and temperature data. The absolute differences between sensor output and criterion values of temperature, humidity, and step count were also determined. RESULTS: Pressure measurements from electronic sensors correlated highly with criterion values (r > or =.82), both before and after prolonged use. Relative humidity sensor output were within 5% of hygrometer values. In-shoe temperature data correlated highly with criterion values (r > or =.99), and differed from known temperatures by.50 degrees +/-.84 degrees C and.96 degrees +/- 1.56 degrees C at the forefoot and heel, respectively. Electronic step counts recorded at the central forefoot were within 1 step of visual step counts. Pressure tracings obtained from the device during different weight-bearing activities revealed qualitatively distinct pressure patterns. CONCLUSION: The device provides valid and reliable measures of in-shoe plantar pressures, temperature, and humidity during prolonged activity.

Accuracy and reliability testing of a portable soft tissue indentor.

We have designed, built, and tested a portable indentor device that allows us to determine force/displacement (F/D) measurements on soft tissue in a clinical or research setting. The indentor system consists of a load cell mounted on a three-dimensional measurement device (Metrecom). The output of the load cell and the Metrecom are recorded and analyzed by software running on a notebook computer. The displacement calibration of the Metrecom gave an average error = 0.005 mm [standard deviation (SD) = 0.062)]. The force calibration of the load cell resulted in an average error = 0.022 N (SD = 0.049) and a linearity of 1.0062 (R2 = 0.9998). The indentor device was tested on six different human soft tissues by two different investigators. The interreliabilities and intrareliabilities were 0.99 [interclass correlation (ICC)] indicating that the results were repeatable by more than one investigator. F/D measurements from indentor testing on two materials were comparable to values measured using an Instron device (5.34 versus. 5.52 N/mm, and 0.98 versus 1.04 N/mm). The device was used to measure the soft tissue characteristics on the plantar surface of the foot of one subject. These data were used to calculate the effective Young's modulus for the tissue using equations derived by Zheng et al. [1] and indicated a wide range of values dependent upon the portion of the F/D curve used. All results indicate data from this portable indentor device are reliable, accurate, and sensitive enough to identify mechanical properties of human tissues.

Precision and accuracy of computed tomography foot measurements.

OBJECTIVE: To test the accuracy and precision of computed tomography (CT) imaging for describing the 3-dimensional structure of the foot in patients with diabetes mellitus and peripheral neuropathy. DESIGN: Experimental, test-retest. SETTING: Clinical CT scanner at a local hospital. SPECIMENS: Two tissue-equivalent phantoms and 6 cadaver feet. MAIN OUTCOME MEASURES: Measurements taken from CT data of phantoms and cadaver feet were compared with physical (caliper) measurements. The feasibility of creating a computer-aided design/rapid prototyping 3-dimensional model from CT data was assessed by using 1 cadaver foot. RESULTS: No bias was found for phantom or cadaver CT measurements compared with caliper measurements. The mean difference between repeat scans of cadaver feet (1 observer) was 0.1 +/- 0.8 mm and between observers, 0.4 +/- 0.8 mm. Comparing caliper measurements of the rapid prototype model and actual foot measurements revealed an error of 0.3 +/- 0.4 mm. CONCLUSION: CT-based 3-dimensional imaging produced accurate and precise foot measurements, enabling description of internal and external structures. This capability will be coupled with plantar pressure measurements to improve our understanding and treatment of foot ulcers in people with diabetes.

In-shoe multisensory data acquisition system.

Patients with diabetes and peripheral neuropathy are susceptible to unnoticed trauma on the foot that can cause skin breakdown. We have designed an electronic system in a shoe that monitors temperature, pressure, and humidity, storing the data in a battery-powered device for later uploading to a host computer for data analysis. The pressure sensors are located at the heel, and under three metatarsal heads. Temperature sensors are located under the medial metatarsal head and under the heel. The humidity sensor is located in the toe of the shoe. Correlations of data from pressure sensors with known values were high (r > 0.85), even after extended use. Although data currently are being collected for descriptive purposes, the design potentially can be used to provide feedback to patients.

Analysis of oxidative stress and wound-inducible dinor isoprostanes F(1) (phytoprostanes F(1)) in plants.

Isoprostanes F(2) are arachidonate autoxidation products in mammals that have been shown to be induced during several human disorders associated with enhanced free-radical generation. Isoprostanes F(2) represent not only extremely reliable markers of oxidative stress in vivo, but they also exert potent biological effects. Therefore, it has been postulated that isoprostanoids are mediators of oxidant injury in vivo. Higher plants, however, do not synthesize arachidonic acid or isoprostanes. Here we show that a series of isoprostane F(2) analogs termed phytoprostanes F(1) (previously dinor isoprostanes F(1)) are formed by an analogous pathway from alpha-linolenate in plants. High-performance liquid chromatography and gas chromatography-mass spectrometry methods using [(18)O](3)phytoprostanes F(1) as internal standard have been developed to quantify phytoprostanes F(1). In fresh peppermint (Mentha piperita) leaves, phytoprostanes F(1) were found in free form (76 ng/g of dry weight) and at about 150-fold higher levels esterified in lipids. It is notable that these levels of phytoprostanes F(1) are more than two orders of magnitude higher than the basal levels of isoprostanes F(2) in mammalian tissues. Furthermore, wounding, as well as butyl hydroperoxide or cupric acetate stress triggered a dramatic increase of free and esterified phytoprostanes F(1). Thus phytoprostanes F(1) may represent a sensitive measure of oxidative damage in plants similar to isoprostanes in mammals. However, one of the most exciting issues to be clarified is the possibility that linolenate-derived phytoprostanes F(1) exert biological activities in plants and/or animals.

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

STUDY DESIGN: Descriptive study to compare relationships between muscle performance measures in 2 subject groups. OBJECTIVES: To determine the relationships between plantar flexor (PF) muscle stiffness, strength (concentric peak torque), and dorsiflexion (DF) range of motion (ROM) in subjects with diabetes who have peripheral neuropathy (n = 17, 10 men, 7 women; age = 58 +/- 11 years) and age-matched controls (n = 17, 10 men, 7 women; age = 62 +/- 6 years). BACKGROUND: The relationships between muscle stiffness, strength, and joint ROM have not been clearly established. Furthermore, the effect of neuromuscular pathology on these relationships is unknown. METHODS AND MEASURES: PF stiffness and strength measurements were obtained with an isokinetic dynamometer. DF ROM was measured with a goniometer. A Pearson correlation matrix was constructed for each subject group using stiffness, strength, and ROM variables. The percent contribution of passive torque to total torque was computed at 2 joint angles. RESULTS: In subjects with diabetes and peripheral neuropathy (DM-PN) peak concentric PF torque was positively correlated with passive torque at 5 degrees DF (r = 0.77), Stiffness #1 (r = 0.58), and Stiffness #2 (r = 0.50). The percentage of passive PF torque at 5 degrees DF was greater in subjects with DM-PN, compared to control subjects (29.3 +/- 9.4% versus 12.6 +/- 5.9%). CONCLUSIONS: The positive correlation between PF stiffness and strength, and the greater percentage of passive PF torque in subjects with DM-PN suggest that patients with decreased strength may use passive torque to maximize total torque. Therefore, treatment methods designed to decrease stiffness should be used cautiously.

Assessment of the diabetic foot using spiral computed tomography imaging and plantar pressure measurements: a technical report.

Persons with diabetes mellitus (DM) and peripheral neuropathy are at high risk for skin breakdown due to unnoticed excessive pressures to the plantar foot during walking. We developed methods that combined spiral x-ray computed tomography (SXCT) imaging and plantar pressure analysis to quantify internal foot structure and external pressure during plantar loading. Methods were tested using a subject with DM who had a plantar ulcer, and a healthy control. SXCT measurements were within 2 mm of truth and SXCT plantar recordings were within 6.5% of walking trials. Hammer toe deformity (second toe), severe atrophy of the intrinsic muscles and less contact area during plantar loading, and a peak plantar pressure three times greater at the site of the ulcer were measured in the diabetic foot as compared with the healthy control. This preliminary investigation suggests that these methods are accurate for structural and pressure measurements of diabetic and healthy feet.

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.

Formation of isoprostane F(2)-like compounds (phytoprostanes F(1)) from alpha-linolenic acid in plants.

Isoprostanes F(2) are biologically active prostaglandin F(2)-like compounds formed by free radical-catalyzed oxidation of arachidonic acid (C20:4). Here, we show that a series of dinor isoprostanes F(1), which we term phytoprostanes F(1) (PPF(1)s), are formed by nonenzymatic oxidation of linolenate (C18:3) in plants. Identification and quantification of PPF(1)s were achieved by a negative ion chemical ionization gas chromatography-mass spectrometry method using oxygen 18-labeled PPF(1)s as internal standards. PPF(1)s were found in leaves, flowers, and roots of taxonomically distinct plant species at concentrations ranging from 43 to 1380 ng/g of dry weight. In addition, esterified PPF(1)s were found at 10- to 150-fold higher concentrations. During the drying and storage of various plant organs, endogenous PPF(1) levels increased dramatically by 15- to 263-fold. Because the structurally related prostaglandin F(2alpha) and isoprostanes F(2) exert potent biological activities (i.e., broncho- and vasoconstriction) in the nanomolar range, PPF(1)s could potentially exert similar biological activities. Notably, fresh birch pollen, which can easily be inhaled, contains exceedingly high concentrations (32,440 ng/g) of free PPF(1)s.

Passive ankle stiffness in subjects with diabetes and peripheral neuropathy versus an age-matched comparison group.

BACKGROUND AND PURPOSE: Patients with diabetes mellitus and peripheral neuropathy (DM and PN) often complain of joint stiffness. Although stiffness may contribute to some of the impairments and functional limitations found in these patients, it has not been quantified in this population. The purpose of this study was to quantify and compare passive ankle stiffness and dorsiflexion (DF) range of motion in subjects with DM and PN versus an age-matched comparison group. SUBJECTS: Thirty-four subjects were tested (17 subjects with DM and PN and 17 subjects in an age-matched comparison group). There were 10 male subjects and 7 female subjects in each group. METHODS: A Kin-Com dynamometer was used to measure passive plantar flexor torque as each subject's ankle was moved from plantar flexion into dorsiflexion at 60(/s. The following variables were compared using a Student t test: initial angle (angle of onset of plantar flexor torque), maximal dorsiflexion angle, plantar flexor muscle excursion (difference between initial angle and maximal dorsiflexion angle), slope of the first half of the plantar flexor torque curve (stiffness 1 measurement), and slope of the second half of the plantar flexor torque curve (stiffness 2 measurement). RESULTS: The subjects with DM and PN had smaller maximal dorsiflexion angles and less plantar flexor muscle excursion than the comparison group. There was no difference in initial angle, stiffness 1 measurement, or stiffness 2 measurement. CONCLUSION AND DISCUSSION: Although the subjects with DM and PN had less dorsiflexion range of motion than did the comparison group, there was no difference in stiffness between the groups. This finding suggests that people with DM and PN have "short" versus "stiff" plantar flexor muscles.

Effects of a tendo-Achilles lengthening procedure on muscle function and gait characteristics in a patient with diabetes mellitus.

STUDY DESIGN: Case report with repeated measures. OBJECTIVES: To describe the effects of a tendo-Achilles lengthening (TAL) and total contact casting (TCC) on wound healing, motion, plantar pressure, and function in a patient with diabetes mellitus, peripheral neuropathy, neuropathic ulcer, and limited dorsiflexion range of motion (DFROM). BACKGROUND: Limited DFROM has been associated with increased forefoot pressures and skin breakdown. A TAL was expected to increase DFROM and reduce forefoot pressures during walking, but the influence on muscle performance and function was unknown. METHODS AND MEASURES: The patient was a 42-year-old man with a 20-year history of type 1 diabetes (NIDDM) and a recurrent neuropathic plantar ulcer. Outcome measures were DFROM, isokinetic plantar flexor muscle peak torque, in-shoe and barefoot peak plantar pressure, physical performance test (PPT) score, and peak ankle and hip moments during walking obtained from an automated gait analysis. All tests were completed pre-TAL, 8 weeks post-TAL (after immobilization in a TCC), and 7 months post-TAL. RESULTS: The wound healed in 40 days. The TAL resulted in a sustained increase in DFROM (0 to 18 degrees). Plantar flexor peak torque was reduced by 21% 8 weeks after the TAL compared with the torque before surgery but recovered fully at 7 months. Seven months following TAL, in-shoe forefoot peak plantar pressure was reduced by 55%, barefoot pressure decreased by 14%, PPT score increased by 24%, peak ankle plantar flexor moment remained decreased by 30%, and the peak hip flexor moment increased by 41% during walking. CONCLUSION: For this patient, a TAL resulted in short-term deficits in peak plantar flexor torque, but a 7-month follow-up showed improvements in ankle DFROM, walking ability, and a decrease in forefoot in-shoe peak plantar pressure.