Gait symmetry - A valid parameter for pre and post planning for total knee arthroplasty

Objectives:We aimed to determine whether GS can help to plan and rearrange the treated side by using IMUs to measure the joint angle of the hip, knee, and ankle. We hypothesized that the kinematics in healthy individuals for both sides are approximately equal during walking.Methods:IMUs were used to measure the joint angles of 25 healthy participants during walking. The participants performed the 10-meter walk test. The normalized symmetry index (SI_norm) was used to calculate the symmetry of joint angles for the hip, knee, and ankle throughout the gait cycle.Results:The SI_norm demonstrated high symmetry between both legs; and the ranges were -1.5% and 1.1% for the hip, -3.0% and 3.1% for the knee, and -12% and 9.2% for the ankle joint angle throughout the gait cycle.Conclusion:The SI_norm provides strong information that can be helpful in the planning process for the surgeries. Further, the IMUs system gives the possibility to measure the patients before their surgeries and use their data to plan and rearrange for the operated side.     

Stability of immobilized soybean lipoxygenases: influence of coupling conditions on the ionization state of the active site Fe

The potential application of lipoxygenase as a versatile biocatalyst in enzyme technology is limited by its poor stability. Two types of soybean lipoxygenases, lipoxygenase-1 and -2 (LOX-1 and LOX-2) were purified by a two step anion exchange chromatography. Four different commercially available supports: CNBr Sepharose 4B, Fractogel((R)) EMD Azlactone, Fractogel((R)) EMD Epoxy, and Eupergit((R)) C were tested for immobilization and stabilization of the purified isoenzymes. Both isoenzymes gave good yields in enzyme activity and good stability after immobilization on CNBr Sepharose 4B and Fractogel((R)) EMD Azlactone. Rapid decay in activity associated with change in the ionization state of Fe, as shown by EPR measurements was observed within the first 5 days after immobilization on epoxy activated supports (Eupergit((R)) C and Fractogel((R)) EMD Epoxy) in high ionic strength buffers. Stabilization of the biocatalyst on these supports was achieved by careful adjustment of the immobilization conditions. When immobilized in phosphate buffer of pH 7.5 and low ionic strength (0.05 M), the half-life time of the immobilized enzyme increased 20 fold. The dependence of the stability of LOX immobilized on epoxy activated supports on the coupling conditions was attributed to a modulation of the ligand environment of the iron in the active site and consequently its reactivity.     

Effects of long-term immobilization and recovery on human triceps surae and collagen turnover in the Achilles tendon in patients with healing ankle fracture.

The aim of the present study was to analyze how human tendon connective tissue responds to an approximately 7-wk period of immobilization and a remobilization period of a similar length, in patients with unilateral ankle fracture, which is currently unknown. Calf muscle cross-sectional area (CSA) decreased by 15% (5,316 to 4,517 mm2) and strength by 54% (239 to 110 N.m) in the immobilized leg after 7 wk. During the 7-wk remobilization, the CSA increased by 9% (to 4,943 mm2) and strength by 37% (to 176 Nm). Achilles tendon CSA did not change significantly during either immobilization or remobilization. Local collagen turnover was measured as the peritendinous concentrations of NH2-terminal propeptide of type I collagen (PINP) and COOH-terminal telopeptide region of type I collagen (ICTP), markers thought to be indexes of type I collagen synthesis and degradation, respectively. Both markers were increased (PINP: 257 vs. 56 ng/ml; ICTP: 9.8 vs. 2.1 microg/l) in the immobilized leg compared with the control leg after the 7 wk of immobilization, and levels decreased again in the immobilized leg during the recovery period (PINP: 103 vs. 44 ng/ml; ICTP: 4.2 vs. 1.9 microg/l). A significant reduction in calf muscle CSA and strength was found in relation to 7 wk of immobilization. Immobilization increased both collagen synthesis and degradation in tendon near tissue. However, it cannot be excluded that the facture of the ankle in close proximity could have affected these data. Remobilization increased muscle size and strength and tendon synthesis and degradation decreased to baseline levels. These dynamic changes in tendon connective tissue turnover were not associated with macroscopic changes in tendon size.     

Use of a Static Progressive Stretch Orthosis to Treat Post-Traumatic Ankle Stiffness

ABSTRACT: BACKGROUND: Chronic ankle stiffness can develop for numerous reasons after traumatic injury, and may adversely affect patient gait, mobility, and function. Although standard physical therapeutic techniques typically resolve this stiffness, some cases may be recalcitrant to these measures, making it difficult to restore range-of-motion. The purpose of this study was to evaluate a static progressive stretch orthosis for the treatment of persistent ankle stiffness. METHODS: Twenty-six patients (26 ankles) who had persistent post-traumatic ankle stiffness were studied. The patients began treatment at a mean of 47 weeks (range, 6 to 272 weeks) following their initial injury using a static progressive stretch orthosis. A patient-directed protocol was used for 30 minutes per day, 1 to 3 times per day, until the range-of-motion was considered to have plateaued. Mean treatment time was 10 weeks (range, 3 to 19 weeks). Treatment duration, range-of-motion, and complications with the device were assessed. RESULTS: The overall mean improvement in motion (combined dorsiflexion and plantar flexion) was 17 degrees (range, 2 to 44 degrees). There was a mean improvement in dorsiflexion of 9 degrees (range, -2 to 20 degrees), and a mean improvement of 8 degrees of plantar flexion (range, -10 to 35 degrees). There were no reports of numbness or skin problems. CONCLUSIONS: The outcomes of this study suggest that a patient-directed treatment protocol using a static progressive stretch orthosis was an effective ancillary method for the treatment of persistent post-traumatic ankle stiffness that was refractory to standard physical therapy techniques. Key Words: ankle; stiffness; orthosis; progressive stress relaxation; rehabilitation.     

Knee stiffness is a major determinant of leg stiffness during maximal hopping

Understanding stiffness of the lower extremities during human movement may provide important information for developing more effective training methods during sports activities. It has been reported that leg stiffness during submaximal hopping depends primarily on ankle stiffness, but the way stiffness is regulated in maximal hopping is unknown. The goal of this study was to examine the hypothesis that knee stiffness is a major determinant of leg stiffness during the maximal hopping. Ten well-trained male athletes performed two-legged hopping in place with a maximal effort. We determined leg and joint stiffness of the hip, knee, and ankle from kinetic and kinematic data. Knee stiffness was significantly higher than ankle and hip stiffness. Further, the regression model revealed that only knee stiffness was significantly correlated with leg stiffness. The results of the present study suggest that the knee stiffness, rather than those of the ankle or hip, is the major determinant of leg stiffness during maximal hopping.     

Inter-joint coupling effects on muscle contributions to endpoint force and acceleration in a musculoskeletal model of the cat hindlimb

The biomechanical principles underlying the organization of muscle activation patterns during standing balance are poorly understood. The goal of this study was to understand the influence of biomechanical inter-joint coupling on endpoint forces and accelerations induced by the activation of individual muscles during postural tasks. We calculated induced endpoint forces and accelerations of 31 muscles in a 7 degree-of-freedom, three-dimensional model of the cat hindlimb. To test the effects of inter-joint coupling, we systematically immobilized the joints (excluded kinematic degrees of freedom) and evaluated how the endpoint force and acceleration directions changed for each muscle in 7 different conditions. We hypothesized that altered inter-joint coupling due to joint immobilization of remote joints would substantially change the induced directions of endpoint force and acceleration of individual muscles. Our results show that for most muscles crossing the knee or the hip, joint immobilization altered the endpoint force or acceleration direction by more than 90° in the dorsal and sagittal planes. Induced endpoint forces were typically consistent with behaviorally observed forces only when the ankle was immobilized. We then activated a proximal muscle simultaneous with an ankle torque of varying magnitude, which demonstrated that the resulting endpoint force or acceleration direction is modulated by the magnitude of the ankle torque. We argue that this simple manipulation can lend insight into the functional effects of co-activating muscles. We conclude that inter-joint coupling may be an essential biomechanical principle underlying the coordination of proximal and distal muscles to produce functional endpoint actions during motor tasks.     

Effects of ankle position during static stretching for the hamstrings on the decrease in passive stiffness

Static stretching is frequently performed to improve flexibility of the hamstrings, although the ankle position during hamstring stretching has not been fully investigated. We investigated the effects of ankle position during hamstring stretching on the decrease in passive stiffness. Fourteen healthy men performed static stretching for the hamstrings with the ankle dorsiflexed and plantar-flexed in a randomized order on different days. The hip was passively flexed to the maximum angle which could be tolerated without stretch pain with the knee fully extended; this was maintained for 5 min, with 1-min stretching performed in 5 sessions. Final angles and passive stiffness were measured before and after stretching. The final angle was defined as that formed by the tibia and horizontal plane when the knee was passively extended from hip and knee angles at 90° flexion to the maximum extension angle which could be tolerated without stretch pain. Passive stiffness was determined by the slope of torque–angle curve during the measurement of the final angle. The final angle significantly increased after stretching with the ankle dorsiflexed and plantar-flexed, whereas passive stiffness significantly decreased only after stretching with the ankle planter-flexed. The results suggest that passive stiffness decreases after stretching with the ankle planter-flexed but not after stretching with the ankle dorsiflexed, although the range of joint motion increases regardless of the ankle position during 5-min stretching for the hamstrings. These results indicate that static stretching should be performed with the ankle plantar-flexed when aiming to decrease passive stiffness of the hamstrings.     

Preparation and characterization of Rhizopus amyloglucosidase immobilized on poly(o-toluidine)

The starch hydrolyzing enzyme amyloglucosidase (AMG) from Rhizopus was immobilized onto the protonated salt (TS) and basic (TB) forms of chemically synthesized poly(o-toluidine) (POT) using adsorption and covalent binding. The polymers were activated with glutaraldehyde prior to covalent bonding. The immobilization efficiency was affected by the pH of the immobilization medium, contact time and amount of enzyme. After immobilization, the pH and temperature were changed to conditions under which the enzyme is most active. Immobilized AMG was more stable with respect to changes in pH and increases in temperature compared to free AMG. The immobilized enzyme retained high catalytic activity after multiple uses and showed enhanced stability with storage compared to free enzyme.     

Changes in stretch reflexes and muscle stiffness with age in prepubescent children.

Musculo-articular stiffness of the triceps surae (TS) increases with age in prepubescent children, under both passive and active conditions. This study investigates whether these changes in muscle stiffness influence the amplitude of the reflex response to muscle stretch. TS stiffness and reflex activities were measured in 46 children (7-11 yr old) and in 9 adults. The TS Hoffmann reflex (H reflex) and T reflex (tendon jerk) in response to taping the Achilles tendon were evaluated at rest and normalized to the maximal motor response (Mmax). Sinusoidal perturbations of passive or activated muscles were used to evoke stretch reflexes and to measure passive and active musculoarticular stiffness. The children's Hmax-to-Mmax ratio did not change with age and did not differ from adult values. The T-to-Mmax ratio increased with age but remained significantly lower than in adults. Passive stiffness also increased with age and was correlated with the T-to-Mmax ratio. Similarly, the children's stretch reflex and active musculoarticular stiffness were significantly correlated and increased with age. We conclude that prepubescent children have smaller T reflexes and stretch reflexes than adults, and the lower musculoarticular stiffness is mainly responsible for these smaller reflexes, as indicated by the parallel increases in reflex and stiffness.     

Immobilization of soybean seed coat peroxidase on polyaniline: Synthesis optimization and catalytic properties

Soybean seed coat peroxidase (SBP) was immobilized on various polyaniline-based polymers (PANI), activated with glutaraldehyde. The most reduced polymer (PANIG₂) showed the highest immobilization capacity (8.2 mg SBP?g^?1 PANIG₂). The optimum pH for immobilization was 6.0 and the maximum retention was achieved after a 6-h reaction period. The efficiency of enzyme activity retention was 82%. When stored at 4°C, the immobilized enzyme retained 80% of its activity for 15 weeks as evidenced by tests performed at 2-week intervals. The immobilized SBP showed the same pH-activity profile as that of the free SBP for pyrogallol oxidation but the optimum temperature (55°C) was 10°C below that of the free enzyme. Kinetic analysis show that the K_m was conserved while the specific V_max dropped from 14.6 to 11.4 µmol min^?1 µg^?1, in agreement with the immobilization efficiency. Substrate specificity was practically the same for both enzymes. Immobilized SBP showed a greatly improved tolerance to different organic solvents; while free SBP lost around 90% of its activity at a 50% organic solvent concentration, immobilized SBP underwent only 30% inactivation at a concentration of 70% acetonitrile. Taking into account that immobilized HRP loses more than 40% of its activity at a 20% organic solvent concentration, immobilized SBP performed much better than its widely used counterpart HRP.     

Convenient one-step purification and immobilization of lipase using a genetically encoded aldehyde tag

To avoid the unwanted and random covalent linkage between the cross-linker and enzyme's active site in covalent immobilization, a genetically encoded “aldehyde tag” was introduced into recombinant lipase and applied for the one-step purification and covalent immobilization of this enzyme. The effects of the immobilization time, temperature and the amount of enzyme were investigated, and the thermo-stability of immobilized lipase was also examined. The specific activity and the k_cat/K_m of the immobilized lipase using aldehyde tag (IL-AT) were 2.50 and 3.02 fold higher, respectively, than those of the traditionally immobilized lipase using glutaraldehyde (IL-GA). The newly immobilized lipase also presented better thermo-stability than the traditionally immobilized one. The results show that the recombinant enzyme could be conveniently immobilized without glutaraldehyde and that the enzyme's active site was well protected. This is a new immobilization method able to avoid glutaraldehyde or 2,4,6-trichloro-1,3,5-triazine as an activating agent. The greener method without hazardous chemicals for the one-step purification and immobilization of an enzyme using a genetically encoded “aldehyde tag” can be exploited for numerous other enzyme purification and immobilization applications.     

Leg and Joint Stiffness in Children with Spastic Diplegic Cerebral Palsy during Level Walking

Individual joint deviations are often identified in the analysis of cerebral palsy (CP) gait. However, knowledge is limited as to how these deviations affect the control of the locomotor system as a whole when striving to meet the demands of walking. The current study aimed to bridge the gap by describing the control of the locomotor system in children with diplegic CP in terms of their leg stiffness, both skeletal and muscular components, and associated joint stiffness during gait. Twelve children with spastic diplegia CP and 12 healthy controls walked at a self-selected pace in a gait laboratory while their kinematic and forceplate data were measured and analyzed during loading response, mid-stance, terminal stance and pre-swing. For calculating the leg stiffness, each of the lower limbs was modeled as a non-linear spring, connecting the hip joint center and the corresponding center of pressure, with varying stiffness that was calculated as the slope (gradient) of the axial force vs. the deformation curve. The leg stiffness was further decomposed into skeletal and muscular components considering the alignment of the lower limb. The ankle, knee and hip of the limb were modeled as revolute joints with torsional springs whose stiffness was calculated as the slope of the moment vs. the angle curve of the joint. Independent t-tests were performed for between-group comparisons of all the variables. The CP group significantly decreased the leg stiffness but increased the joint stiffness during stance phase, except during terminal stance where the leg stiffness was increased. They appeared to rely more on muscular contributions to achieve the required leg stiffness, increasing the muscular demands in maintaining the body posture against collapse. Leg stiffness plays a critical role in modulating the kinematics and kinetics of the locomotor system during gait in the diplegic CP.     

Immobilization of alliinase on porous aluminum oxide

Membrane filters prepared from porous aluminum oxide (Anopore) were investigated for their potential use as a durable support for enzymes. Alliinase (EC 4.4.1.4) was chosen as a model enzyme for immobilization experiments. To allow for smooth fixation, the enzyme was immobilized indirectly by sugar-lectin binding. Monomolecular layers of the lectin concanavalin A and alliinase were applied by self-assembling processes. As an anchor for these layers, the sugar, mannan, was covalently coupled to the membrane surface. This procedure exhibits several advantages: (i) enzyme immobilization can be carried out under smooth conditions; (ii) immobilization needs little time; and (iii) protein layers may be renewed.     

Expression,purification and immobilization of the intracellular invertase INVA,from <Emphasis Type="Italic">Zymomonas mobilis</Emphasis> on crystalline cellulose and Nylon-6

This paper presents two immobilization methods for the intracellular invertase (INVA), from Zymomonas mobilis. In the first method, a chimeric protein containing the invertase INVA, fused through its C-terminus to CBD _Cex from Cellulomonas fimi was expressed in Escherichia coli strain BL21 (DE3). INVA was purified and immobilized on crystalline cellulose (Avicel) by means of affinity, in a single step. No changes were detected in optimal pH and temperature when INVA-CBD was immobilized on Avicel, where values of 5.5 and 30 °C, respectively, were registered. The kinetic parameters of the INVA-CBD fusion protein were determined in both its free form and when immobilized on Avicel. K _m and V _max were affected with immobilization, since both showed an increase of up to threefold. Additionally, we found that subsequent to immobilization, the INVA-CBD fusion protein was 39% more susceptible to substrate inhibition than INVA-CBD in its free form. The second method of immobilization was achieved by the expression of a 6xHis-tagged invertase purified on Ni-NTA resin, which was then immobilized on Nylon-6 by covalent binding. An optimal pH of 5.5 and a temperature of 30 °C were maintained, subsequent to immobilization on Nylon-6 as well as with immobilization on crystalline cellulose. The kinetic parameters relating to V _max increased up to 5.7-fold, following immobilization, whereas K _m increased up to 1.7-fold. The two methods were compared showing that when invertase was immobilized on Nylon-6, its activity was 1.9 times that when immobilized on cellulose for substrate concentrations ranging from 30 to 390 mM of sucrose.     

Changes of bone morphology in response to hindlimb suspension of rats.

Effects of chronic hindlimb suspension or exposure to 2-G from postnatal day 4 to month 3 followed by ambulation recovery on the floor on the morphology of hindlimb bones were investigated in rats. The dorsi-flexion of the ankle was inhibited in the suspended group and such phenomena were not recovered at all. The mean weight and length of femur, tibia, and fibula were less than the cage controls at the end of suspension, but gradually increased during recovery. However, they were still less than those of the age-matched controls even after 3-month recovery. External bending of shaft and rotation of distal end of tibia were observed in the suspended group and these phenomena were not recovered at all. These morphological changes caused the inhibition of dorsi-flexion of ankle joints. The electromyogram activities of ankle plantar-flexors, soleus, plantaris, lateral gastrocnemius, were inhibited and those of dorsi-flexor, tibialis anterior, were increased during suspension. Typical changes in bone morphology were not induced by exposure to 2-G. It was suggested that gravitational unloading during developing period causes irreversible inhibition of normal bone growth. It was also indicated that the suspension-related changes in bone morphology may be caused by abnormal mechanical stress due to the altered mobilization of hindlimb muscles.     

Passive resistance of the human knee: The effect of immobilization

The effects of immobilization on both the circumferential dimensions of the lower limb, and the passive resistance of the knee to sinusoidal motion in the flexion-extension plane, were studied in patients immobilized after tibial fractures or ligamentous injuries of the knee. Immobilization resulted in a decrease of circumferential dimensions of the lower limb, indicating atrophy of thigh and calf musculature. The equilibrium angle of the knee, i.e. the angle at which the net passive moment equals zero, approached the angle of the knee during immobilization. At knee angles of 60° (the maximal angle imposed on the immobilized knee) and 45°, the resistance was increased, and at angles of 30° and 15°, the resistance was decreased. The passive resistances at ± 22.5, 15 and 7.5° relative to the equilibrium angle were all increased. A simple model, taking into account changes in the length of muscles at the anterior and posterior side of the knee, explains changes in passive resistance. The duration of immobilization for patients with ligamentous injuries of the knee was less than 50% of that for patients with tibial fractures, whose ankle joint was not immobilized, both resulted in a smaller muscular atrophy for patients with ligamentous injuries. Differences in passive resistance between unaffected and immobilized legs were the same in both groups of patients. Changes in passive resistance in the immobilized leg for those with ligamentous injury are probably not the effect of immobilization alone but the combined effect of immobilization and ligamentous lesions.     

Evaluation of musculotendinous stiffness in prepubertal children and adults, taking into account muscle activity.

Musculotendinous (MT) stiffness of the triceps surae (TS) muscle group was quantified in 28 prepubertal children (7-10 yr) by using quick-release movements at different levels of submaximal contractions. Surface electromyograms (EMG) of each part of the TS and of the tibialis anterior were also recorded. A stiffness index, defined as the slope of the angular stiffness-torque relationship (SIMT-Torque), was used to quantify changes in MT stiffness with age. Results showed a significant decrease in SIMT-Torque with age, ranging from 4.02 +/- 0.29 to 2.88 +/- 0.31 rad-1 for the youngest to the oldest children. Because an increase in stiffness with age was expected due to the maturation of elastic tissues, overactivation of the TS was suspected to contribute to the higher SIMT-Torque values found in the youngest children. TS EMG-torque analyses confirmed that neuromuscular efficiency was significantly lower for the 7- or 8-yr-old children compared with 10-yr-old children, notably due to a higher degree of tibialis anterior coactivation found in the youngest children. Thus the stiffness index originally defined as the slope of the angular stiffness-EMG relationship increased significantly with age toward adult values. The results underlined the necessity to take into account the capacities of muscle activation to quantify changes in elastic properties of muscles, when those capacities are suspected to be altered.     

Immobilization of glucose oxidase and lactate dehydrogenase onto magnetic nanoparticles for bioprocess monitoring system

Glucose oxidase (GOD) and lactate dehydrogenase (LDH) were immobilized onto magnetic nanoparticles, viz. Fe₃O₄, via carbodiimide and glutaraldehyde. The immobilization efficiency was largely dependent upon the immobilization time and concentration of glutaraldehyde. The magnetic nanoparticles had a mean diameter of 9.3 nm and were superparamagnetic. The immobilization of GOD and LDH on the nanoparticles slightly decreased their saturation magnetization. However, the FT-IR spectra showed that GOD and LDH were immobilized onto the nanoparticles by different binding mechanisms, the reason for which was not well explained. The optimum pH values of the immobilized GOD and LDH were changed to 8 and 10, respectively. The free and immobilized enzyme kinetic parameters (K_m and V_max) were determined by Michaelis-Menten enzyme kinetics. The Km values for free and immobilized GOD were 0.168 and 0.324 mM, respectively, while those for free and immobilized LDH were 0.19 and 0.163 mM for NAD, and 2.976 and 4.785 mM for lactate, respectively. High operational stability was observed, with more than 80% of the initial enzyme activity being retained for the immobilized GOD up to 12 h and for the immobilized LDH up to 24 h. The immobilized GOD was applied to a sequential injection analysis system for the application of bioprocess monitoring.     

Application and characterization of magnetic chitosan microspheres for enhanced immobilization of cellulase

In this study, a unique carrier magnetic chitosan microspheres (MCTS) was simply synthesized by anchoring Fe₃O₄ onto chitosan for direct immobilization of cellulases cross-linked by gluteraldehye. The structure and morphology were characterized using FT-IR, TGA, VSM and SEM. The optimum immobilization conditions were investigated: immobilized pH 7.0, amount of enzyme 15?mL (0.1?mg/mL), immobilization temperature 30?°C, immobilization time 5?h. At optimum conditions, MCTS achieved maximum enzyme solid loading rate of 73.5?mg/g, while recovery of enzyme activity approached to 71.6%. In the recycle test, immobilized cellulases operated without significant loss in its initial performances after 3 cycles, which indicated that immobilized cellulases can be regenerated and reused. The immobilized enzyme has better values of thermal and storage stability than that of free enzyme. Therefore, MCTS may be considered as a candidate with potential value of application in large-scale operations for cellulases immobilization.     

The effect of isokinetic dynamometer deceleration phase on maximum ankle joint range of motion and plantar flexor mechanical properties tested at different angular velocities

During range of motion (max-ROM) tests performed on an isokinetic dynamometer, the mechanical delay between the button press (by the participant to signal their max-ROM) and the stopping of joint rotation resulting from system inertia induces errors in both max-ROM and maximum passive joint moment. The present study aimed to quantify these errors by comparing data when max-ROM was obtained from the joint position data, as usual (max-ROM_POS), to data where max-ROM was defined as the first point of dynamometer arm deceleration (max-ROM_ACC). Fifteen participants performed isokinetic ankle joint max-ROM tests at 5, 30 and 60° s⁻¹. Max-ROM, peak passive joint moment, end-range musculo-articular (MAC) stiffness and area under the joint moment-position curve were calculated. Greater max-ROM was observed in max-ROM_POS than max-ROM_ACC (P < 0.01) at 5 (0.2 ± 0.15%), 30 (1.8 ± 1.0%) and 60° s⁻¹ (5.9 ± 2.3%), with the greatest error at the fastest velocity. Peak passive moment was greater and end-range MAC stiffness lower in max-ROM_POS than in max-ROM_ACC only at 60° s⁻¹ (P < 0.01), whilst greater elastic energy storage was found at all velocities. Max-ROM and peak passive moment are affected by the delay between button press and eventual stopping of joint rotation in an angular velocity-dependent manner. This affects other variables calculated from the data. When high data accuracy is required, especially at fast joint rotation velocities (≥30° s⁻¹), max-ROM (and associated measures calculated from joint moment data) should be taken at the point of first change in acceleration rather than at the dynamometer’s ultimate joint position.