PubMed Health⌕ Search

Biomedical subjects

S F Figoni

Publications and source records attributed to S F Figoni.

At least 19 recordsLinked to original sources
PubMed2000

The measurement properties of fitness measures and health status for persons with spinal cord injuries.

OBJECTIVE: To assess the measurement properties of measures used to evaluate fitness and health status in the spinal cord injury (SCI) population. DESIGN: Inception cohort assessed during standardized exercise protocols at admission, discharge, and 8-week follow-up from a SCI rehabilitation program. SETTING: Urban tertiary care hospital. PATIENTS: One hundred two patients with SCI. RESULTS: Measures at higher levels of physical exertion generally showed higher stability between test and retest. Resting measures, blood lactates, and respiratory exchange ratios were not stable. Heart rate, blood pressure, lactate levels, ventilation rates, and activities of daily living measures did not reflect the construct of aerobic fitness. The use of ratings of perceived exertion to predict heart rate was found to be inaccurate in the SCI population. CONCLUSION: Power output and VO2 at maximal workload, and ratings of perceived exertion at a standard workload demonstrated stability and sensitivity to therapeutic change, indicating acceptable measurement properties for the assessment of aerobic fitness in SCI patients. Some other commonly used measures can be used with less confidence.

Adult↗
PubMed1999

High density lipoprotein cholesterol in individuals with spinal cord injury: the potential role of physical activity.

STUDY DESIGN/METHODS: Literature review. Papers were selected from a literature search of both the Medline and Current Contents data bases and through extensive cross checking of references from the author's personal files. OBJECTIVES: To evaluate the evidence for a reduced level of HDL-C in individuals with spinal cord injury and to discuss physiologic and behavioral factors that may be responsible for the observed reduction, with emphasis on the role of physical activity. RESULTS/CONCLUSIONS: The evidence presented suggests that HDL-C may be lower in persons with SCI; however, the available data should be interpreted cautiously due to lack of control for important confounding factors such as smoking, alcohol consumption and physical activity. Results suggest a potential association between increased physical activity and increased HDL-C in persons with SCI. However, the mode, frequency, intensity and duration of activity and the physiologic mechanism responsible for this association have yet to be clearly elucidated.

Cholesterol, HDL↗
PubMed1998

A submaximal all-extremity exercise test to predict maximal oxygen consumption.

PURPOSE: Submaximal aerobic exercise testing is utilized with a variety of populations to assess fitness level and predict maximal oxygen uptake (VO2peak) when a maximal test is not possible or preferable. Many submaximal tests have been developed on traditional exercise equipment, such as the treadmill and the cycle ergometer, but are not available for newer equipment such as an all-extremity ergometer. The purpose of this study was to develop and validate a submaximal exercise test using the Pro II Power Trainer, an all-extremity ergometer, in women ages 30-60 without disability and with varying fitness levels. A secondary purpose was to compare VO2peak values achieved during the all-extremity maximal test and the treadmill test. METHODS AND RESULTS: A linear regression equation was developed to predict VO2peak from submaximal data using heart rates and power output at the sixth and ninth minutes of the submaximal test. The linear regression derived for the submaximal all-extremity test was VO2peak L.min-1 = -0.01 (age in years) - 0.0029 (HR 1) - 0.0099 (HR2) - 0.0029 (PO1) + 0.0151(PO2) + 3.010. Predicted residual sum of squares of the linear equation revealed an R2 value of 0.722 and standard error of estimate of 0.216 L.min-1. Treadmill VO2 speak values correlated strongly with all-extremity VO2 speak values (r = 0.918) and were not significantly different (P, 0.05). CONCLUSION: A similar submaximal test needs to be developed for field estimates of VO2peak for subpopulations of individuals with physical disabilities such as rheumatoid arthritis, head or spinal cord injury, cerebral vascular accident, multiple sclerosis, amputation, and cerebral palsy.

Adult↗
PubMed1997

Electrical stimulation-induced contraction to reduce blood stasis during arthroplasty.

Deep venous thrombosis and subsequent pulmonary embolism due to venous pooling/stasis commonly occur in patients during hip and/or knee arthroplasty (i.e., replacement). This problem may be alleviated by using techniques to promote lower limb blood flow. Electrical stimulation-induced contractions have been shown to activate the skeletal muscle pump, promote limb blood flow, and may be effective for reducing venous pooling/stasis and edema. Therefore, electrical stimulation may reduce the incidence of deep venous thrombosis (DVT) and pulmonary embolism (PE) during and following surgery. The overall goal of this project was to evaluate the clinical efficacy of sequential electrical stimulation-induced leg muscle contractions on the venous blood flow during surgery. The degree of venous pooling/stasis was monitored via electrical impedance changes in the thorax. The changes in the patient's central hemodynamics were then calculated. Thirty patients were recruited and randomly assigned to either a control group (n = 15, mean age = 66.4 +/- 7.3) or experimental group (n = 15, age = 60.7 +/- 9.7). Both groups received the standard medical treatment for prevention of DVT (i.e., coumadin, heparin, etc.) and compression stockings (TED, Kendall). The control group used the sequential compression device (SCD + TED) and the experimental group used electrical stimulation (ES + TED). Electrical stimulation was applied via surface electrodes to the lower-limb muscles (tibialis anterior and gastrocnemius) and upper limb muscles (quadriceps femoris and hamstrings). These muscles contracted sequentially, using an eight-channel electrical stimulator. Four seconds of calf (contraction/compression) were followed by 7-s of calf and thigh (contraction/compression) interspersed by 60-s rest period during both electrical stimulation or sequential compression device. This cycle continued throughout the surgery (60-75 min) for both groups. At 15 min intervals, venous return was monitored by impedance cardiograph. Physiologic responses including ventricular stroke volume (SV), cardiac output (CO), heart rate (HR), total peripheral resistance (TPR), as well as mean arterial pressure (MAP) were monitored. These responses were statistically analyzed and compared throughout the surgery within each group and between the two groups. The results show stroke volume and cardiac output to be higher throughout surgery in the electrical stimulation group as compared with the sequential compression device group. The heart rate was consistently lower during electrical stimulation for both groups. Total peripheral resistance did not change in the electrical stimulation group; but increased in the sequential compression device group. The data suggest that continuous electrical stimulation-induced contractions could improve lower leg circulation by eliciting the physiologic muscle pump. This will lead to improved venous circulation and reduction of blood stasis during total hip and/or knee surgery. This technique may offer greater protection against DVT and PE during surgery than the commonly used sequential compression device.

Bandages↗
PubMed1994

Biomechanics of wheelchair propulsion during fatigue.

Musculoskeletal injuries can result from overuse or incorrect use of manual wheelchairs, and can hinder rehabilitation efforts. The purpose of this study was to investigate wheelchair propulsion biomechanics of spinal cord injured, non-athletic wheelchair users. We studied changes in the variables that occur with fatiguing wheelchair propulsion to determine how the user's physical characteristics and the state of fatigue influence risk of injury. Twenty male paraplegic patients were videotaped during propulsion to fatigue on a stationary, instrumented wheelchair positioned on a roller with adjustable frictional resistance. Peak handrim force was significantly correlated with concentric shoulder flexion and elbow extension isokinetic torques. Significant changes (p < 0.05) with fatigue were found in increased peak handrim force, decreased ulnar/radial deviation range of motion, and increased trunk forward lean. Of the three upper extremity joints, highest calculated joint moments were found in shoulder flexion (p < 0.05). These biomechanical results suggest that potentially harmful changes occur with fatigue, and that the shoulder may be the most prone to musculotendinous-type overuse injury.

Adult↗
PubMed1993

Exercise responses and quadriplegia.

The purpose of this paper is to review the exercise physiology literature on spinal cord injured individuals with quadriplegia performing voluntary arm exercise and/or electrically stimulated leg exercise. The effects of level of injury, active muscle mass, and sympathetic dysfunction on acute physiologic adjustments during exercise testing and chronic training adaptations are discussed. Several topics for future research are suggested, including methods to achieve higher aerobic/cardiovascular fitness, reduce secondary cardiovascular/pulmonary disabilities and related health care costs, and promote health, wellness, and an active lifestyle.

Cardiovascular System↗
PubMed1992

Metabolic and hemodynamic responses to concurrent voluntary arm crank and electrical stimulation leg cycle exercise in quadriplegics.

This study determined the metabolic and hemodynamic responses in eight spinal cord injured (SCI) quadriplegics (C5-C8/T1) performing subpeak arm crank exercise (ACE) alone, subpeak functional electrical stimulation leg cycle exercise (FES-LCE) alone, and subpeak FES-LCE concurrent with subpeak ACE (hybrid exercise). Subjects completed 10 minutes of each exercise mode during which steady-state oxygen uptake (VO2), pulmonary ventilation (VE), heart rate (HR), cardiac output (CO), stroke volume (SV), mean arterial pressure (MAP), arteriovenous oxygen difference (a-v O2 diff), and total peripheral resistance (TPR) were determined. Although mean VO2 for both ACE alone and FES-LCE alone was matched at 0.66 l/mi, individualized power outputs ranged from 0-30 W (mean = 19.4 +/- 1.3) and 0-12.2 W (mean = 2.3 +/- 0.6), respectively. Hybrid exercise elicited significantly higher VO2 (by 54 percent), VE (by 39-53 percent), HR (by 19-33 percent), and CO (by 33-47 percent), and significantly lower TPR (by 21-34 percent) than ACE or FES-LCE performed alone (P less than or equal to 0.05). Stroke volume was similar between hybrid exercise and FES-LCE alone, and these two exercise modes evoked a significantly higher SV (by 41-56 percent) than during ACE alone. These data clearly demonstrate that hybrid exercise creates a higher aerobic metabolic demand and cardiac-volume load in SCI quadriplegics than either subpeak levels of ACE or FES-LCE performed separately. Therefore, hybrid exercise may provide more advantageous central cardiovascular training effects in quadriplegics than either ACE or FES-LCE alone.

Adult↗
PubMed1992

Functional electrical stimulation leg cycle ergometer exercise: training effects on cardiorespiratory responses of spinal cord injured subjects at rest and during submaximal exercise.

This study investigated the cardiorespiratory (CR) responses at rest and during submaximal (0-W) functional electrical stimulation (FES)-induced leg cycle ergometer (LCE) exercise prior to and following a progressive intensity FES-LCEa exercise training program in spinal cord injured (SCI) subjects. Seven quadriplegics and six paraplegics participated in FES-LCE training three sessions per week for approximately 12 weeks (36 sessions). Monitored CR responses, including oxygen uptake (VO2), pulmonary ventilation (VE), respiratory exchange ratio (RER), arteriovenous O2 difference (a-vO2), blood pressure (BP), heart rate (HR), stroke volume (SV), total peripheral resistance (TPR), and cardiac output (Q), were determined before and after training. Power output (PO) increased significantly (p < .05) over the duration of the training program, indicating increased in strength and endurance of the paralyzed muscles used. Respiratory responses were not significantly altered by training in both groups. FES-LCE training significantly increased resting HR and SBP in quadriplegics and lowered SBP, DBP, and MAP in paraplegics. In both groups, HR and BP during submaximal exercise significantly decreased and SV and Q significantly increased after completion of the training program. These results suggest that FES-LCE training improves peripheral muscular and central cardiovascular fitness in SCI subjects. Posttraining HR and BP may also be more stable in quadriplegics and alleviate hypotension. This therapeutic exercise may ultimately lead to improved rehabilitation outcome and reduced stress during activities of daily living, and possibly reduce the risks for secondary CR disabilities.

Adult↗
PubMed1992

Physiologic effects of electrical stimulation leg cycle exercise training in spinal cord injured persons.

The purpose of this study was to assess the physiologic training effects of functional electrical stimulation leg cycle ergometer (FES-LCE) exercise in persons with spinal cord injury (SCI) who were previously untrained in this activity. Ten persons with quadriplegia (C5 to C7) and eight with paraplegia (T4 to T11) performed FES-LCE training on an ERGYS I ergometer 10 to 30 minutes per day, 2 or 3 days per week for 12 to 16 weeks (36 total sessions). Training session power output (PO) ranged from 0.0W (no external resistance) to 30.6W. Each subject completed discontinuous graded FES-LCE and arm crank ergometer (ACE) tests before and after training for determinations of peak lower and upper extremity metabolic, pulmonary, and hemodynamic responses. Compared with pretraining, this SCI group exhibited significantly (p less than or equal to .05) higher posttraining peak PO (+45%), oxygen uptake ([O2], + 23%), pulmonary ventilation (+27%), heart rate (+11%), cardiac output ([Qt], + 13%) and significantly lower total peripheral resistance ([TPR], - 14%) during FES-LCE posttests. There were no significant changes in peak stroke volume (+6%), mean arterial pressure ([MAP], - 5%), or arteriovenous oxygen difference ([a-vO2diff], + 10%) during posttraining FES-LCE tests. In addition, no significant differences were noted for the peak level of any monitored variable during ACE posttests after FES-LCE training. The rise in total vascular conductance, implied by the significant decrease in posttraining TPR during FES-LCE tests, denotes that a peripheral circulatory adaptation developed in the persons with SCI during FES-LCE exercise training.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Adaptive control of functional neuromuscular stimulation-induced knee extension exercise.

An automated system for exercising the paralyzed quadriceps muscles of spinal cord injured patients using functional neuromuscular stimulation (FNS) has been developed. It induces smooth concentric and eccentric contractions in both limbs to enable bilateral 70 degree knee extensions in an asynchronous pattern. External load resistance is applied at the ankle level to "overload" the muscles and bring about training effects. The system uses adaptive control methods to adjust FNS current output (threshold level and the ramp slope) to the quadriceps muscles to maintain performance as the muscles fatigue. Feedback control signals for limb movement and knee extension angle are used to continuously adjust the FNS current parameters so that the external load is moved through the preset zero to 70 degree angle range. Typically, the threshold current level and the FNS current increase as the muscles fatigue to maintain performance with repetitive contractions. Fatigue is defined as the inability to extend the knee to 50 percent of the 70 degree target angle. When this occurs, FNS is automatically terminated for the fatigued leg, while the functioning leg continues to exercise. The automated nature of this system appears to be advantageous as compared to a manually operated system for subject safety, convenience, and uniformity of exercise bouts. Simulated safety problems, such as hyperextension of the knee joint, open circuitry, muscle spasms, and low battery power, were successfully detected by the logic circuitry, and the system followed appropriate safety procedures to minimize risk.

Electric Stimulation↗
PubMed1991

Acute hemodynamic responses of spinal cord injured individuals to functional neuromuscular stimulation-induced knee extension exercise.

The purpose of this study was to determine and compare acute hemodynamic responses of spinal cord injured (SCI) quadriplegics (quads), and paraplegics (paras) during a graded-intensity knee extension (KE) exercise test utilizing functional neuromuscular stimulation (FNS) of paralyzed quadriceps muscles. Seven quads and seven paras (N = 14) performed a series of 4-minute stages of bilateral alternating FNS-KE exercise (approximately zero to 70 degree range of motion at the knee and 6 KE/min/leg) at ankle loads of 0, 5, 10, and 15 kg/leg. Physiologic responses were determined with open-circuit spirometry, impedance cardiography, and auscultation. Comparing rest with peak FNS-KE for both groups combined, FNS-KE exercise elicited significant (p less than 0.05) increases in oxygen uptake (130 percent), pulmonary ventilation (120 percent), respiratory exchange ratio (37 percent), arteriovenous oxygen difference (57 percent), cardiac output (32 percent), stroke volume (41 percent), mean arterial pressure (18 percent), and rate-pressure product (23 percent). Heart rate increased significantly by 11 percent from the 5- to the 15-kg/leg stages. Physiologic responses of quads and paras were very similar, except for lower (p less than 0.05) arterial pressures, rate-pressure product, and peripheral vascular resistance in quads. This graded FNS-KE exercise up to the 15-kg/leg load induced relatively small but appropriate increases in aerobic metabolism and cardiopulmonary responses that appear to be safe and easily tolerated by quads and paras. Arterial pressure needs to be monitored carefully in quads to prevent excessive hypertension or hypotension. Although FNS-KE exercise has been shown to elicit peripheral adaptations to improve muscle strength and endurance, it is probably not an effective central cardiovascular training tool for all but the least fit SCI individuals. This information is important for understanding the effects of FNS use during more complex activities such as cycling and ambulation.

Adult↗
PubMed1991

Musculoskeletal responses of spinal cord injured individuals to functional neuromuscular stimulation-induced knee extension exercise training.

This study was conducted to evaluate a newly designed functional neuromuscular stimulation (FNS)-induced knee extension (KE) exercise system that incorporates the most desired features of previously described systems by determining the musculoskeletal responses of spinal cord injured (SCI) individuals to training. A specially designed chair and electrical stimulator were fabricated for FNS-induced KE resistance exercise. Surface electrodes were placed over motor points of the quadriceps muscles, and KE was alternated between legs at an average rate of 6 KE/min/leg. KE testing protocols were developed for pre- and post-training evaluations of performance, and 12 SCI subjects exercise-trained up to three times per week for 36 sessions using a progressive resistance load at ankle level. Pre- and post-training evaluation data were statistically compared using a 0.05 level for significance. Quadriceps muscle performance (strength x repetitions) improved for both legs in all subjects as indicated by significant increases in load resistance and repetitions over the 36-session training period (right leg mean = 1156.0 versus 1624.8 kg.reps, left leg mean = 1127.3 versus 1721.1 kg.reps). In addition, knee range of motion significantly increased (right leg mean = 134 versus 146 degrees, left leg mean = 133 versus 144 degrees). Thigh skinfold, thigh girth, body weight and bone density were not significantly changed. The lack of decrease in bone density in some subjects suggests that the training may retard the rate of bone loss which typically occurs with SCI. No injuries or problems were encountered during testing and training.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Physiologic responses of paraplegics and quadriplegics to passive and active leg cycle ergometry.

The purposes of this study were three-fold: (a) to determine acute physiologic responses of spinal cord injured (SCI) subjects to peak levels of leg cycle ergometry utilizing functional neuromuscular stimulation (FNS) of paralyzed leg muscles, (b) to determine the relative contributions of passive and active components of FNS cycling to the peak physiologic responses, and (c) to compare these physiologic responses between persons who have quadriplegia and those who have paraplegia. Thirty SCI subjects (17 quadriplegics and 13 paraplegics) performed a discontinuous graded FNS exercise test from rest to fatigue on an ERGYS 1 ergometer. Steady-state physiologic responses were determined by open-circuit spirometry, impedance cardiography with ECG, and auscultation. In the combined statistics of both groups, it was noted that peak FNS cycling significantly increased (from rest levels) mean oxygen uptake by 255%, arteriovenous O2 difference VO2 and VE, Q and a-vO2 and VCO by 69%, and stroke volume by 45%, while total peripheral vascular resistance decreased by 43%. Mean peak power output for paraplegics (15 W) was significantly higher than for quadriplegics (9 W), eliciting higher peak levels of pulmonary ventilation and sympathetically mediated hemodynamic responses such as cardiac output, heart rate, and systolic and diastolic arterial blood pressure. Passive cycling without FNS produced no statistically significant increases in physiologic responses above the resting level in either group.

Adult↗
PubMed1990

Perspectives on cardiovascular fitness and SCI.

The purpose of these papers is to review and discuss the fundamental concepts and problems underlying cardiovascular fitness and spinal cord injury. Particular attention is paid to several modes of exercise available to individuals with spinal cord injury (SCI)--voluntary arm-crank and wheelchair ergometry, electrical stimulation leg cycle ergometry, and combined voluntary arm-cranking and electrical stimulation leg (hybrid) exercise. The effects of level of injury, active muscle mass, and sympathetic dysfunction upon acute central hemodynamic adjustments during exercise testing and chronic training adaptations are discussed for both quadriplegics and paraplegics. Several topics for future research are suggested.

Cardiovascular System↗
PubMed1990

Physiologic responses to prolonged electrically stimulated leg-cycle exercise in the spinal cord injured.

This study determined the physiologic responses to prolonged functional neuromuscular stimulation (FNS) leg-cycle exercise in seven quadriplegic and seven paraplegic subjects. Each subject completed 30 minutes of continuous FNS leg cycling during which open-circuit spirometry, impedance cardiography, auscultation, and fingertip capillary blood sampling were used to assess metabolic and hemodynamic responses. Compared with resting values, oxygen uptake, carbon dioxide production, respiratory exchange ratio (RER), pulmonary ventilation, heart rate (HR), left ventricular stroke volume (SV), cardiac output (Qt), and blood lactate (La) concentration were significantly (p less than .05) elevated, whereas plasma volume, bicarbonate concentration, and pH were significantly decreased in both groups during prolonged FNS leg-cycle exercise. Mean arterial pressure remained unchanged in quadriplegic and paraplegic subjects during the prolonged FNS leg-cycle exercise bout. Persons with quadriplegia elicited significantly lower MAP and tended to have lower SV and Qt responses than persons with paraplegia, probably due to a higher degree of sympathetic dysfunction and circulatory hypokinesis during FNS leg-cycle exercise. All other physiologic variables responded similarly between groups. We speculate that the relative increases observed for HR (33% to 60%), SV (45% to 69%), and Qt (113% to 142%) during prolonged FNS leg-cycle exercise create a sufficient cardiac-volume load to promote central cardiovascular conditioning in persons with both quadriplegia and paraplegia. The La accumulation (4.7 to 5.2 mmol.L-1) in the spinal cord injured during prolonged FNS leg cycling is unusually high for the power output attained (5.2W and 6.1W for quadriplegia and paraplegia, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Cardiovascular and haemodynamic responses to tilting and to standing in tetraplegic patients: a review.

This paper has reviewed the acute and long-term responses to changes in vertical posture in normal and tetraplegic subjects. It has discussed physiological mechanisms causing orthostatic hypotension in acute cervical spinal cord injured patients, and subsequent factors contributing to its amelioration over time. The long-term adaptive mechanisms are still controversial, probably involving multiple neurological, endocrine, renal, cardiovascular and haemodynamic factors. These factors include inhibition of vagal tone, plasma catecholamine levels, sensitivity of vascular beds to catecholamines, stretch reflexes in blood vessels, spinal BP reflexes, renin-angiotensin system, aldosterone and plasma volume changes. Individual differences may also interact with these various mechanisms, further complicating the issues. Although the fact that most tetraplegics do improve their orthostatic tolerance over time with repeated tilting is manifest, the precise mechanisms allowing this improvement are not. Research is needed to clarify these adaptive mechanisms, as well as to investigate the physiological effects of long-term therapeutic standing in devices such as standing frames.

Blood Circulation↗
PubMed1984

Upper limb exercise effect on tilt tolerance during orthostatic training of patients with spinal cord injury.

Twelve male patients with traumatic spinal cord injury were randomly divided into a group of six experimental and six control subjects. All subjects were tilted from 0 degree to 70 degrees by 10 degrees increments at five-minute intervals until blood pressure dropped below 70/40, hypotensive symptoms appeared, or 70 degrees of tilt was achieved. The experimental subjects performed 60 active bilateral full-range forearm flexion and extension movements per minute during the first and third minute of each tilt angle. The control patients did not perform upper limb exercises during the same orthostatic training procedure. Blood pressure and pulse rate of all subjects were recorded prior to orthostatic training, during the training at specified intervals and posttraining on each day of testing and training. Total group response was quantitated by indicating the tilting protocol step at which subjects experienced orthostatic hypotension requiring termination of the test. All subjects significantly increased their tolerance of higher tilt angles by using this protocol, but there was no significant difference between the exercise group and nonexercise group with reference to tolerance to progressive vertical tilt (Mann-Whitney U test).

Adult↗