PubMed Health⌕ Search

Biomedical subjects

R J Triolo

Publications and source records attributed to R J Triolo.

At least 19 recordsLinked to original sources
PubMed2001

Architecture of the rectus abdominis, quadratus lumborum, and erector spinae.

Quantitative descriptions of muscle architecture are needed to characterize the force-generating capabilities of muscles. This study reports the architecture of three major trunk muscles: the rectus abdominis, quadratus lumborum, and three columns of the erector spinae (spinalis thoracis, longissimus thoracis and iliocostalis lumborum). Musculotendon lengths, muscle lengths, fascicle lengths, sarcomere lengths, pennation angles, and muscle masses were measured in five cadavers. Optimal fascicle lengths (the fascicle length at which the muscle generates maximum force) and physiologic cross-sectional areas (the ratio of muscle volume to optimal fascicle length) were computed from these measurements. The rectus abdominis had the longest fascicles of the muscles studied, with a mean (S.D.) optimal fascicle length of 28.3 (4.2)cm. The three columns of the erector spinae had mean optimal fascicle lengths that ranged from 6.4 (0.6)cm in the spinalis thoracis to 14.2 (2.1)cm in the iliocostalis lumborum. The proximal portion of the quadratus lumborum had a mean optimal fascicle length of 8.5 (1.5)cm and the distal segment of this muscle had a mean optimal fascicle length of 5.6 (0.9)cm. The physiologic cross-sectional area of the rectus abdominis was 2.6 (0.9)cm(2), the combined physiologic cross-sectional area of the erector spinae was 11.6 (1.8)cm(2), and the physiologic cross-sectional area of the quadratus lumborum was 2.8 (0.5)cm(2). These data provide the basis for estimation of the force-generating potential of these muscles.

Aged↗
PubMed2001

Surgical technique for installing an eight-channel neuroprosthesis for standing.

A standardized surgical procedure to implant an eight-channel functional neuromuscular stimulation system in the lower extremities for standing, exercise, and transfers for individuals with spinal cord injury has been developed. The implanted components include: (1) one eight-channel receiver-stimulator, (2) epimysial electrodes, (3) intramuscular electrodes, and (4) inline connectors. The development process included identifying the target muscle set for electrode placement and the corresponding surgical approaches, determining the stages of the surgical procedure, and assessing the effectiveness and stability of the implanted neuroprosthesis. The bilateral muscle set consists of the vastus lateralis, the gluteus maximus, the semimembranosus, and the erector spinae. Surgical approaches to the nerve entry points were developed through a series of cadaveric studies and intraoperative tests. Electrode placement is related to bony landmarks and based on standard orthopaedic approaches. The components of the neuroprosthesis are installed in one surgical session, with three stages. This procedure has been applied successfully in seven individuals, resulting in strong, isolated stimulated contractions adequate to raise and lower the body, maintain standing with a walker, and perform pivot transfers. The standardized surgical procedure is repeatable and teachable and will be used in upcoming multicenter clinical trials of the implanted neuroprosthesis.

Adult↗
PubMed2001

Modeling the postural disturbances caused by upper extremity movements.

This paper describes the design, validation, and application of a dynamic, three-dimensional (3-D) model of the upper extremity for the purpose of estimating postural disturbances generated by movements of the arms. The model consists of two links representing the upper and lower arms, with the shoulder and elbow modeled as gimbal joints to allow three rotational degrees of freedom. With individualized segment inertial parameters based on anthropometric measurements, the model performs inverse dynamic analysis of recorded arm movements to calculate reaction forces and moments acting on the body at the shoulder in three dimensions. The method was validated by comparing the output of the model to estimates obtained from ground reaction loads during stereotypical and free form unilateral movements at various velocities and with different loads carried by human subjects while seated on biomechanical force platforms. The correlation between predicted and measured reaction forces and moments was very good under all conditions and across all subjects, with average rms errors less than 8% of measured peak-to-peak values. The model was then applied to bimanual activities representative of functional movements that would typically be performed while standing at a counter. The resulting estimates were consistent and adequate for the purpose of evaluating postural disturbances caused by upper extremity movements.

Adult↗
PubMed2000

The use of selective electrical stimulation of the quadriceps to improve standing function in paraplegia.

Persons with spinal cord injury (SCI) can benefit significantly from functional neuromuscular stimulation (FNS) systems for standing if manual tasks can be performed while upright. Using FNS to sufficiently activate the knee extensors to rise from a sitting position often results in inadvertent activation of the rectus femoris and/or sartorius, which flex the hip. In this study, intramuscular electrodes implanted in the vastus lateralis and medialis of four subjects with SCI were used to activate these muscles individually and simultaneously to measure knee extension moment. Support forces applied to the arms and feet were measured while upright to quantify the effects of recruiting rectus femoris and/or sartorius. In three of the four subjects, vastus lateralis, by itself, generated adequate knee extension moment for rising from a chair and to maintain static standing. Simultaneous activation of the vastus lateralis and medialis using a bifurcated electrode generated adequate knee extension moment in one subject, and was within 10% of the required moment in another. While upright, activation of the rectus femoris resulted in arm support force increases of 4-11% body weight, while deactivation resulted in arm support force decreases of 6-9% body weight. The results indicate that selective activation of the vastus lateralis, individually or in combination with vastus medialis, can improve current FNS standing systems by reducing the arm support forces required to remain upright.

Biomechanical Phenomena↗
PubMed1999

Walking with a hybrid orthosis system.

OBJECTIVE: The purpose of this case study was to determine the functional effectiveness of the hybrid orthosis system (HOS) for sit-to-stand and walking compared with the reciprocal gait orthosis (RGO) alone in a subject with significant orthopedic abnormalities. DESIGN: A subject with complete T7 paraplegia and a 13 cm leg length discrepancy was implanted with 14 intramuscular electrodes and fitted with a custom isocentric RGO. The subject was instructed in the use of the HOS and a two wheeled walker in the home and community settings. MAIN OUTCOME MEASURES: Using the Functional Independence Measure (FIM), and the Borg exertion scale the subject's level of independence and his perceived exertion was determined as well as the safety and efficacy of system use in the community. RESULTS: Results show that the HOS provided safe, independent ambulation with a two wheeled walker and met established criteria for limited community use. Walking in the RGO alone was feasible, however, the addition of functional electrical stimulation (FES) allowed this subject to walk farther and with less perceived exertion. CONCLUSION: This case study suggests that a hybrid orthosis system can be an effective clinical option for individuals with significant orthopedic complications that might otherwise contra-indicate the prescription of either conventional braces or FES alone.

Adult↗
PubMed1999

Implanted functional electrical stimulation system for mobility in paraplegia: a follow-up case report.

A 16-channel functional electrical stimulation (FES) system has been implanted in a person with T10 paraplegia for over a year. The system consists of two eight-channel radio frequency controlled receiver-stimulators delivering stimuli through a network of 14 epimysial and two intramuscular electrodes. Using this system and a walker for support, the subject was able to stand up for 8 min and walk regularly for 20 m. The standing duration was limited by arm fatigue since upper extremities supported an average of 25% of body weight. This was due to suboptimal hip extension and some undesired recruitment of rectus femoris and sartorius with stimulation of quadriceps electrodes. The left quadriceps exhibited rapid fatigue that limited walking distance and duration. The metabolic energy requirements were well within the aerobic limits of the sedentary paraplegic population. At one-year follow-up evaluation all electrodes are functional except one intramuscular electrode. The implant caused no adverse physiological effects and the individual reported health benefits such as increased energy and overall fitness as a result of the FES system use. With further improvements in muscle response through innovative surgical techniques, the 16-channel implanted FES system can be a viable addition to exercise and mobility function in persons with paraplegia.

Adult↗
PubMed1998

Implantation of a 16-channel functional electrical stimulation walking system.

A 16-channel electrical stimulation system was implanted in a 39-year-old patient with T10 paraplegia to restore sit to stand, walking, and exercise functions. System implantation required two surgical sessions. In the first session, the posterior muscle set consisting of bilateral semimembranosus, adductor magnus, and gluteus maximus muscles were exposed and epimysial electrodes sutured at the point of greatest muscle contraction. Closed double helix intramuscular electrodes were implanted in the erector spinae. Two weeks later, epimysial electrodes were attached to the eight anterior muscles consisting of the tibialis anterior, sartorius, tensor fasciae latae, and vastus lateralis with all 16 electrode leads passed to the anterior abdominal wall. The electrodes were connected to two eight-channel stimulators placed in the iliac fossae, and the system was checked by activating the individual muscles. The implanted stimulators received stimulation instructions and power via a radio frequency link to an external control. Stimulation patterns for standing, walking, sitting, and exercise functions were chosen from a preprogrammed menu via a finger key pad. After 3 weeks of restricted patient activity, all electrodes stimulated either the target muscle or had an acceptable spillover pattern. The patient is undergoing a 16-week rehabilitation course of stimulated exercises gradually increasing in intensity. At the conclusion, the goal is to discharge the patient with the system for spontaneous use. Although long term followup is required to determine system reliability, preliminary clinical results indicate that targeted, repeatable, functional muscle contractions in the lower extremity can be achieved with a system consisting of epimysial electrodes.

Adult↗
PubMed1997

Experimental evaluation of an adaptive feedforward controller for use in functional neuromuscular stimulation systems.

An adaptive feedforward control system has been evaluated for use in functional neuromuscular stimulation (FNS) systems. The control system, which utilizes neural network techniques, was used to generate isometric muscle contractions to track a periodic torque trajectory signal. The evaluation of the control system was performed using percutaneous intramuscular electrodes to stimulate the quadriceps muscles of spinal cord injured adolescents. Results of the evaluation indicate that the control system automatically customized its parameters for controlling isometric muscle torque in a particular muscle and that the parameters were adapted on-line to account for changes in muscle properties due to fatigue. This study demonstrates that this control system may play an important role in the development of practical FNS systems that are capable of automatically adjusting stimulation parameters to fit the needs of a particular individual at a given time.

Adaptation, Physiological↗
PubMed1997

Muscle selection and walking performance of multichannel FES systems for ambulation in paraplegia.

A minimal set of muscles (8 to 16) were identified as candidates for implantation in a clinical system to provide walking function to individuals with complete paraplegia using functional electrical stimulation (FES). Three subjects with complete motor and sensory paraplegia had percutaneous intramuscular electrodes implanted in all major muscles controlling the trunk, hips, knees, and ankles. Stimulation patterns for walking with FES were generated for different sets of eight and 16 muscles. The quality and repeatability of the resulting gait produced by walking patterns consisting of various combinations of muscles were determined. Most eight-channel stimulation patterns resulted in scissoring or insufficient hip flexion, preventing forward progression. One eight-channel system allowed a maximum speed of 0.1 m/s with a cadence of 22 steps/min and a stride length less than 0.3 m. Improved walking performance was observed with 16 channels of stimulation. This ranged from slow step- to gait at 0.1 m/s to smooth reciprocal gait at 0.5 m/s. In all three subjects, the favored combination of 16 channels included erector spinae for trunk extension; gluteus maximus, posterior portion of adductor magnus and hamstrings for hip extension; tensor fasciae latae and either sartorius or iliopsoas for hip flexion; vastus lateralis/intermedius for knee extension; and tibialis anterior/peroneous longus for ankle dorsiflexion. In one subject the 16-channel FES system provided repeatable day-to-day gait averaging 0.4 m/s, 58 steps/min and a stride length at 0.8 m. A maximum repeatable walking distance with 16 channels was 34 m. Multiple 34-m trials were possible with minimal rests between walks. Fatigue of both the hip extensors and upper body was a limiting factor. The selection of target muscles for implantation is critical to the performance of FES systems. This study provides guidelines to muscle selection for walking with FES based on objective measures of gait performance. The findings indicate that a 16-channel FES system for total implantation is feasible for repeatable short distance, independent, walker-support walking in paraplegia.

Adult↗
PubMed1996

Home use of a functional electrical stimulation system for standing and mobility in adolescents with spinal cord injury.

OBJECTIVE: Functional electrical stimulation (FES) is a technology that may allow some patients with spinal cord injury (SCI) to integrate standing and upright mobility with wheelchair mobility. The purpose of this study was to document the patterns of home and community use of a FES system for standing and mobility. DESIGN: A telephone questionnaire was administered every 1 to 4 weeks for a minimum of 1 year. An interview was given at the end of the study to probe the motivators and barriers to home use. SETTING: Training for use of the FES system was performed in an inpatient pediatric rehabilitation setting. Data collection began after the subjects were discharged to home. PARTICIPANTS: Five adolescents with complete, thoracic-level SCI. INTERVENTION: Subjects participated in a program of FES exercise followed by training in basic mobility skills such as standing transfers, maneuvering, level ambulation, one-handed and reaching activities, and stair ascent/descent. MAIN OUTCOME MEASURE: The frequency with which the FES system was used at home and the activities for which it was utilized were documented. Motivators and barriers to FES home use were examined. RESULTS: Subjects donned the FES system on the average once every 3 to 4 days. Between 51% and 84% of the times donned, the system was used for exercise. The remaining times it was used for standing activities, most commonly reaching, one-handed tasks, and standing for exercise. "Motivators" included being able to do things that would otherwise be difficult, perceiving a healthful benefit or a sense of well-being from standing and exercise, and feeling an obligation to stand as a participant in a research study. "Barriers" to FES use included not finding time to use the system, having difficulty seeing opportunities to stand, and being reluctant to wear the FES system all day.

Activities of Daily Living↗
PubMed1996

Implanted Functional Neuromuscular Stimulation systems for individuals with cervical spinal cord injuries: clinical case reports.

OBJECTIVE: To determine the feasibility of providing the ability to stand and to facilitate the performance of standing transfers to individuals with cervical-level spinal cord injuries via functional neuromuscular stimulation (FNS). The applicability of implantable technology to this population was investigated, and the characteristics of the potential system users were explored. The effects of FNS on the effort and assistance required to stand and complete standing transfers were examined. SETTING: Institutional rehabilitation practice. DESIGN: Nonrandomized controlled trial. PATIENTS: Twenty-four individuals with low cervical spinal cord injuries were evaluated for inclusion in a program of lower extremity FNS, four of whom received the intervention. INTERVENTION: Chronically indwelling percutaneous intramuscular electrodes were used to exercise the hip, knee, and trunk extensors and develop activation patterns to produce standing function. These temporary systems were then replaced with silicone-enclosed helical wire electrodes suitable for eventual use with an eight-channel implantable receiver/stimulator. MAIN OUTCOME MEASURES: Full sensory and motor evaluations were performed and physical contraindications to stimulation were catalogued. For active subjects, American Spinal Injury Association Total Motor Scores with and without FNS were recorded, along with quadriceps strength and ability to complete exercise, standing, controlled sitting, and standing transfer maneuvers. Performances of implanted electrodes were determined by the stability of recruitment properties, impedances or surface potentials, and serial radiographs. RESULTS: Motor scores increased an average of nine points with stimulation over baseline volitional values. With FNS, all four volunteers were able to exercise, stand, and sit independently or with minimal assistance. Although they required varying degrees of assistance with the pivot phase of the transfer maneuver, all were able to raise and lower their body weight independently with stimulation and to use the system to facilitate standing transfers. One participant received the implantable receiver/stimulator, which remains operational at follow-up more than 3 years later. CONCLUSION: FNS can provide the ability to exercise, stand, and transfer to individuals with tetraplegia, even in the presence of medical complications and upper extremity impairment. FNS facilitates standing transfers by eliminating the heavy lifting usually required by a caregiver, thus decreasing the effort and assistance necessary to gain access to places impossible to approach with conventional sliding transfers.

Adult↗
PubMed1996

Characterization of the bone mineral density of children with spinal cord injury.

The purpose of this study was to compare the bone mineral density in children with spinal cord injury (SCI) with age- and sex-matched controls in three anatomic areas of the proximal hip. In addition, post hoc analysis looked for differences in bone density between sub-groups considering several factors associated with spinal cord injury: the presence or absence of spasticity, the level of injury and the presence or absence of pathologic fractures. Fifty-one pediatric patients with spinal cord injury between the ages of 3 and 20 underwent bone density measurements using dual photon absorptiometry. Before pooling the data across age groups, all measurements were normalized to age- and sex-matched controls because of increasing bone density with growth and higher bone density in males. The results revealed lower bone densities in subjects with SCI as compared with their non-disabled peers, ranging from 56 percent to 65 percent of normal across the three anatomic regions. On the average, subjects who had a previous history of fractures had significantly lower bone density measurements than those without fractures. At the intertrochanteric region, a 10.6 percent difference was noted between subjects with tetraplegia versus those with paraplegia. At the femoral neck and Ward's Triangle, an 8.5 percent difference was noted between subjects with and without spasticity. No conclusions could be drawn from the analyses at the other sites. Together these results begin to characterize bone density levels of the pediatric SCI population.

Adolescent↗
PubMed1996

Motor responses to FES electrodes in a growing limb.

A canine model was used to investigate the chronic performance of surgically implanted electrodes in a growing limb. Seven skeletally immature dogs were implanted with epimysial and intramuscular electrodes. Recruitment characteristics for each electrode, including the activation threshold, spillover muscle threshold, peak force, and force at spillover were recorded with tendon force transducers placed on the tendon of the target muscle and the first spillover muscle. Recruitment properties for the electrodes were measured at the time of implant and after growth was complete. Appropriate electrode positions were also remapped after maturity was reached. Data for 23 electrodes are reported. Average longitudinal growth of the ulna was 5.6 cm (39% increase). The measurements of threshold for target and spillover muscle activation show that appropriate muscle recruitment order was retained in 22 of 23 (96%) of the electrodes. The target muscle thresholds remained stable between implant and explant with variation on the order of that reported for these electrodes placed in mature animals. Overall, a multivariate analysis of variance for repeated measures indicates electrodes performed equally well at explant as they did at implant as measured by threshold and usable range of target muscle before spillover. New electrodes placed in the adult animal did not perform better than the chronically placed electrodes. The recruitment properties of 22 or 23 electrodes did not vary significantly with growth. This is encouraging evidence that a stable motor response can be retained with implantable intramuscular and epimysial electrodes in the presence of growth.

Animals↗
PubMed1995

Inter-rater reliability of a clinical test of standing function.

The Functional Standing Test (FST) has been proposed and described as an evaluative tool to assess a person's ability to perform one-handed reaching tasks while standing. The test items, several of which are identical to those in the Jebson Test of Hand Function, require the manipulation of objects on a counter top and on simulated kitchen shelves while the person is standing. The purpose of this study was to assess the inter-rater reliability of FST when it is administered to adolescents with spinal cord injuries who stand with braces, and to able-bodied young adults. Two testers administered the FST separately to three individuals with spinal cord injuries (SCI) below T-2 who stood with knee-ankle-foot orthoses (KAFOs) and to 10 able-bodied people who stood unassisted. The order in which the testers operated was randomized and the Intraclass Correlation Coefficient (ICC (2,1)) was used to analyze inter-rater reliability. Eighty percent of the subtests were found to be moderately to very reliable when applied to either group on the same day. Half of the test items were categorized as having the same level of inter-rater reliability between the two sample populations. A modified version of the test eliminating unreliable components could serve as a valuable and inexpensive means of evaluating the effectiveness of various therapies and technologies to provide or assist standing function. Validity and specificity of the test remain the focus of future research.

Adolescent↗
PubMed1994

Application of functional neuromuscular stimulation to children with spinal cord injuries: candidate selection for upper and lower extremity research.

This paper summarizes the results of screening for participation in research programs involving functional neuromuscular stimulation (FNS). It examines the characteristics of a group of children and teenagers with spinal cord injuries (SCI) identified as potential candidates for FNS as defined by the rigorous inclusion criteria of the research studies. One hundred and thirteen children and teenagers under the age of 20 with cervical, thoracic or lumbar level spinal cord injuries were examined for inclusion in an experimental program of FNS to provide standing, walking, or prehension. Although biased towards adolescents with complete midthoracic and midcervical injuries, the age, sex, injury level, etiology, and neurological status of the sample coincided with previously published reports and consisted predominantly of teenage males injured in motor vehicle or sports related accidents. Approximately half of the individuals examined were physically appropriate for research participation without preparatory intervention. Treatment options to prepare individuals for FNS were identified in 25% of those considered inappropriate at the initial evaluation, indicating that the potential user population of clinical systems may be larger than estimates obtained from research applications. Peripheral denervation was the single most prevalent physical impediment to the application of FNS. Although the incidence of lower motor neuron (LMN) involvement was similar in subjects with tetraplegia and paraplegia, those with cervical lesions more frequently exhibited other medical complications that interfered with the application of FNS. Surgical procedures involving transfer of paralyzed but excitable muscles were identified in almost one third of the candidates with tetraplegia who were excluded due to denervation. Of those physically appropriate, psychological factors eliminated several candidates from consideration. Such concerns may also be addressed with suitable intervention in preparation for the clinical application of FNS. Almost 50% of those appropriate for FNS research elected to participate in the programs, with those declining citing the hospitalization, time and travel commitments as the primary factors influencing their decisions. Results suggest that FNS for standing, walking and hand grasp may be an option for a significant percentage of the pediatric SCI population.

Adolescent↗
PubMed1994

Functional neuromuscular stimulation: outcomes in young people with tetraplegia.

Percutaneous intramuscular functional neuromuscular stimulation (FNS) systems were fitted to the forearms of five adolescents with tetraplegia in an effort to provide active grasp and release. Two assessments designed at Case Western Reserve University to evaluate functional outcomes of FNS in adults were employed. The common object test (COT) was used to assess hand function during five activities of daily living (ADLs): eating, drinking, writing, brushing teeth and applying toothpaste. A usage survey provided information on the frequency of FNS use in environments outside of the laboratory. In addition, interviews were employed using open-ended questions to gain a deeper understanding of the perceptions of FNS in the adolescents' own environments. Based on the COT results, each adolescent was able to perform ADLs with and without FNS. However, FNS allowed unilateral function so that the extremity without FNS was freed to assist in balance or participate in bilateral tasks. Also, FNS reduced the need for multiple devices, providing users with the potential to perform activities in a variety of environments without transporting adaptive equipment. Those who reported using FNS most often obtained hard-bound school books, held pens during classroom and homework assignments, engaged in leisure activities and performed hygiene tasks. FNS was also used as a means to communicate and socialize through hand gestures. Well-known factors that influence the independence of people with tetraplegia also appeared to affect FNS use.

Activities of Daily Living↗
PubMed1994

Reliability of percutaneous intramuscular electrodes for upper extremity functional neuromuscular stimulation in adolescents with C5 tetraplegia.

Chronically indwelling percutaneous intramuscular electrodes were implanted in the upper extremity muscles of five adolescents with C5 or C5-6 tetraplegia in an effort to provide lateral and palmar prehension using the neuroprosthetic system designed by Case Western Reserve University. The responses from 177 electrodes were evaluated at 3-month intervals and included measurements of electrical impedance and an assessment of recruitment properties. Electrode failures were categorized as breakage, an altered stimulated response or adverse sensation during stimulation. Survival probabilities were generated for all electrodes, each muscle group, the volar and dorsal exit sites, intrinsic and extrinsic muscles, and according to the subjects' time postinjury. The overall probability of an electrode surviving to 6 months was 0.75 and the 1 year survival probability was 0.56. Among muscle groups, the finger extensor and thumb adductor electrodes had the highest proportion of failures and the poorest survival likelihoods within the first year after implant. According to the Breslow test, significantly smaller survival chances were predicted for electrodes exiting dorsally and for the newly-injured adolescents (< 1 year postinjury). The cumulative survival likelihoods of this study are smaller than those reported in adult applications using the same electrode design. Factors that may account for the disparate results are discussed.

Adolescent↗