Interpol Review Paper of Marks and Impression Evidence 2019-2022.

This section contains an overview of publications relevant to advances in scientific methods and general discussions concerning shoe and toolmark examiners, which were published between January 2019 and May of 2022 and is the sequel to the review for the 19th Interpol International Forensic Science Managers Symposium in 2019 by Martin Baiker-Sorensen. A literature search was conducted covering relevant articles published in the main forensic journals.

Effect of Cadence on Time Trial Performance in Recreational Female Cyclists.

Graham, PL, Zoeller, RF, Jacobs, PL, and Whitehurst, MA. Effect of cadence on time trial performance in recreational female cyclists. J Strength Cond Res 32(6): 1739-1744, 2018-The impact of pedaling cadence on cycling performance remains unresolved especially in female cyclists. The purpose of this study was to determine the effect of cadence on time trial (TT) performance in recreational female cyclists. Ten recreational female cyclists volunteered to participate in this study. Subjects performed 3 exercise sessions: 1 to assess peak oxygen uptake (V[Combining Dot Above]O2peak) and 2 TTs. Cadence was randomly ordered and fixed for each TT (60 or 100 rpm), whereas power output (PO) was freely adjusted by the participant, as tolerated. Time trial time, heart rate (HR), blood lactate, PO, V[Combining Dot Above]O2, and ratings of perceived exertion were measured throughout the TTs. The major finding of this study was the significantly faster (p = 0.001) TT time during the 60-rpm condition (34:23 ± 4:21) vs. the 100-rpm condition (37:34 ± 5:53). Also the 60-rpm TT resulted in significant differences for HR (155.9 ± 3.97 vs. 161.2 ± 5.20 b·min, p = 0.04), gross efficiency, (21.1 ± 0.37 vs. 17.7 ± 0.85%, p < 0.001), and PO (147 ± 7.06 vs. 129 ± 10.62 W, p = 0.003). Thus, a slower cycling cadence was associated with greater mechanical efficiency and PO, resulting in significantly better performance in a TT. These results suggest that recreational female cyclists may benefit from adopting a low cadence during an 8-km TT.

Validation of cell-based fluorescence assays: practice guidelines from the ICSH and ICCS - part V - assay performance criteria.

Multi-color flow cytometry is a unique technology, which enables the analysis of heterogeneous cellular systems and provides multiparametric information on a cell-by-cell basis. A variety of factors contribute to the complexity of validating cell-based flow cytometric methods, including the lack of fully characterized cellular reference materials and the difficulty in obtaining, or creating, samples with varying levels of a given cell type or varying levels of expression of a given antigen. This document summarizes validation requirements and describes validation strategies for quasi-quantitative and qualitative cell-based flow cytometric assays.

Yoga Nidra relaxation increases heart rate variability and is unaffected by a prior bout of Hatha yoga.

OBJECTIVE: The measurement of heart rate variability (HRV) is often applied as an index of autonomic nervous system (ANS) balance and, therefore, myocardial stability. Previous studies have suggested that relaxation or mind-body exercise can influence ANS balance positively as measured by HRV but may act via different mechanisms. No studies, to the authors' knowledge, have examined the acute response in HRV to interventions combining relaxation and mind-body exercise. The objective of this study was to compare the acute HRV responses to Yoga Nidra relaxation alone versus Yoga Nidra relaxation preceded by Hatha yoga. DESIGN: This was a randomized counter-balanced trial. SETTING: The trial was conducted in a university exercise physiology laboratory. SUBJECTS: Subjects included 20 women and men (29.15±6.98 years of age, with a range of 18-47 years). INTERVENTIONS: Participants completed a yoga plus relaxation (YR) session and a relaxation only (R) session. RESULTS: The YR condition produced significant changes from baseline in heart rate (HR; beats per minute [bpm], p<0.001) and indices of HRV: R-R (ms, p<0.001), pNN50 (%, p=0.009), low frequency (LF; %, p=0.008) and high frequency (HF; %, p=0.035). The R condition produced significant changes from baseline in heart rate (bpm, p<0.001) as well as indices of HRV: R-R (ms, p<0.001), HF (ms(2), p=0.004), LF (%, p=0.005), HF (%, p=0.008) and LF:HF ratio (%, p=0.008). There were no significant differences between conditions at baseline nor for the changes from baseline for any of the variables. CONCLUSIONS: These changes demonstrate a favorable shift in autonomic balance to the parasympathetic branch of the ANS for both conditions, and that Yoga Nidra relaxation produces favorable changes in measures of HRV whether alone or preceded by a bout of Hatha yoga.

Comparison of training methods to improve walking in persons with chronic spinal cord injury: a randomized clinical trial.

OBJECTIVE: To compare two forms of device-specific training - body-weight-supported (BWS) ambulation on a fixed track (TRK) and BWS ambulation on a treadmill (TM) - to comprehensive physical therapy (PT) for improving walking speed in persons with chronic, motor-incomplete spinal cord injury (SCI). METHODS: Thirty-five adult subjects with a history of chronic SCI (>1 year; AIS 'C' or 'D') participated in a 13-week (1 hour/day; 3 days per week) training program. Subjects were randomized into one of the three training groups. Subjects in the two BWS groups trained without the benefit of additional input from a physical therapist or gait expert. For each training session, performance values and heart rate were monitored. Pre- and post-training maximal 10-m walking speed, balance, muscle strength, fitness, and quality of life were assessed in each subject. RESULTS: All three training groups showed significant improvement in maximal walking speed, muscle strength, and psychological well-being. A significant improvement in balance was seen for PT and TRK groups but not for subjects in the TM group. In all groups, post-training measures of fitness, functional independence, and perceived health and vitality were unchanged. CONCLUSIONS: Our results demonstrate that persons with chronic, motor-incomplete SCI can improve walking ability and psychological well-being following a concentrated period of ambulation therapy, regardless of training method. Improvement in walking speed was associated with improved balance and muscle strength. In spite of the fact that we withheld any formal input of a physical therapist or gait expert from subjects in the device-specific training groups, these subjects did just as well as subjects receiving comprehensive PT for improving walking speed and strength. It is likely that further modest benefits would accrue to those subjects receiving a combination of device-specific training with input from a physical therapist or gait expert to guide that training.

Long-term glycine propionyl-l-carnitine supplemention and paradoxical effects on repeated anaerobic sprint performance.

BACKGROUND: It has been demonstrated that acute GPLC supplementation produces enhanced anaerobic work capacity with reduced lactate production in resistance trained males. However, it is not known what effects chronic GPLC supplementation has on anaerobic performances or lactate clearance. PURPOSE: The purpose of this study was to examine the long-term effects of different dosages of GPLC supplementation on repeated high intensity stationary cycle sprint performance. METHODS: Forty-five resistance trained men participated in a double-blind, controlled research study. All subjects completed two testing sessions, seven days apart, 90 minutes following oral ingestion of either 4.5 grams GPLC or 4.5 grams cellulose (PL), in randomized order. The exercise testing protocol consisted of five 10-second Wingate cycle sprints separated by 1-minute active recovery periods. Following completion of the second test session, the 45 subjects were randomly assigned to receive 1.5 g, 3.0 g, or 4.5 g GPLC per day for a 28 day period. Subjects completed a third test session following the four weeks of GPLC supplementation using the same testing protocol. Values of peak power (PP), mean power (MP) and percent decrement of power (DEC) were determined per bout and standardized relative to body mass. Heart rate (HR) and blood lactate (LAC) were measured prior to, during and following the five sprint bouts. RESULTS: There were no significant effects of condition or significant interaction effects detected for PP and MP. However, results indicated that sprint bouts three, four and five produced 2 - 5% lower values of PP and 3 - 7% lower values of MP with GPLC at 3.0 or 4.5 g per day as compared to baseline values. Conversely, 1.5 g GPLC produced 3 - 6% higher values of PP and 2 -5% higher values of MP compared with PL baseline values. Values of DEC were significantly greater (15-20%) greater across the five sprint bouts with 3.0 g or 4.5 g GPLC, but the 1.5 g GPLC supplementation produced DEC values -5%, -3%, +4%, +5%, and +2% different from the baseline PL values. The 1.5 g group displayed a statistically significant 24% reduction in net lactate accumulation per unit power output (p < 0.05). CONCLUSIONS: The effects of GPLC supplementation on anaerobic work capacity and lactate accumulation appear to be dosage dependent. Four weeks of GPLC supplementation at 3.0 and 4.5 g/day resulted in reduced mean values of power output with greater rates of DEC compared with baseline while 1.5 g/day produced higher mean values of MP and PP with modest increases of DEC. Supplementation of 1.5 g/day also produced a significantly lower rate of lactate accumulation per unit power output compared with 3.0 and 4.5 g/day. In conclusion, GPLC appears to be a useful dietary supplement to enhance anaerobic work capacity and potentially sport performance, but apparently the dosage must be determined specific to the intensity and duration of exercise.

Caffeine enhances upper body strength in resistance-trained women.

BACKGROUND: Research has indicated that low-to-moderate dosages of caffeine supplementation are ergogenic for sustained endurance efforts as well as high-intensity exercise. The effects of caffeine supplementation on strength-power performance are equivocal, with some studies indicating a benefit and others demonstrating no change in performance. The majority of research that has examined the effects of caffeine supplementation on strength-power performance has been carried out in both trained and untrained men. Therefore, the purpose of this study was to determine the acute effects of caffeine supplementation on strength and muscular endurance in resistance-trained women. METHODS: In a randomized manner, 15 women consumed caffeine (6 mg/kg) or placebo (PL) seven days apart. Sixty min following supplementation, participants performed a one-repetition maximum (1RM) barbell bench press test and repetitions to failure at 60% of 1RM. Heart rate (HR) and blood pressure (BP) were assessed at rest, 60 minutes post-consumption, and immediately following completion of repetitions to failure. RESULTS: Repeated measures ANOVA indicated a significantly greater bench press maximum with caffeine (p

Elbow joint position sense after neuromuscular training with handheld vibration.

CONTEXT: Clinicians use neuromuscular control exercises to enhance joint position sense (JPS); however, because standardizing such exercises is difficult, validations of their use are limited. OBJECTIVE: To evaluate the acute effects of a neuromuscular training exercise with a handheld vibrating dumbbell on elbow JPS acuity. DESIGN: Crossover study. SETTING: University athletic training research laboratory. PATIENTS OR OTHER PARTICIPANTS: Thirty-one healthy, college-aged volunteers (16 men, 15 women, age = 23 + or - 3 years, height = 173 + or - 8 cm, mass = 76 + or - 14 kg). INTERVENTION(S): We measured and trained elbow JPS using an electromagnetic tracking device that provided auditory and visual biofeedback. For JPS testing, participants held a dumbbell and actively identified the target elbow flexion angle (90 degrees ) using the software-generated biofeedback, followed by 3 repositioning trials without feedback. Each neuromuscular training protocol included 3 exercises during which participants held a 2.55-kg dumbbell vibrating at 15, 5, or 0 Hz and used software-generated biofeedback to locate and maintain the target elbow flexion angle for 15 seconds. MAIN OUTCOME MEASURE(S): We calculated absolute (accuracy) and variable (variability) errors using the differences between target and reproduced angles. RESULTS: Training protocols using 15-Hz vibration enhanced accuracy and decreased variability of elbow JPS (P < or = .005), whereas 5-Hz vibration did not affect accuracy (F(1,61) = 2.625, P = .100) but did decrease variability (F(1,61) = 7.250, P = .009). The control condition and 0-Hz training protocol had no effect on accuracy or variability (P > or = .200). CONCLUSIONS: Our results suggest these neuromuscular control exercises, which included low-magnitude, low-frequency handheld vibration, may enhance elbow JPS. Future researchers should examine vibration of various durations and frequencies, should include injured participants and functional multijoint and multiplanar measures, and should examine long-term effects of training protocols on JPS and injury.

Glycine propionyl-L-carnitine produces enhanced anaerobic work capacity with reduced lactate accumulation in resistance trained males.

BACKGROUND: Recent research has indicated that short term administration of glycine propionyl-L-carnitine (GPLC) significantly elevates levels of nitric oxide metabolites at rest and in response to reactive hyperaemia. However, no scientific evidence exists that suggests such supplementation enhances exercise performance in healthy, trained individuals. The purpose of this study was to examine the effects of GPLC on the performance of repeated high intensity stationary cycle sprints with limited recovery periods in resistance trained male subjects. METHODS: In a double-blind, placebo-controlled, cross-over design, twenty-four male resistance trained subjects (25.2 +/- 3.6 years) participated in two test sessions separated by one week. Testing was performed 90 minutes following oral ingestion of either 4.5 grams GPLC or 4.5 grams cellulose (PL), in randomized order. The exercise testing protocol consisted of five 10-second Wingate cycle sprints separated by 1-minute active recovery periods. Peak (PP) and mean values (MP) of sprint power output and percent decrement of power (DEC) were determined per bout and standardized relative to body masss. Heart rate (HR) and blood lactate (LAC) were measured prior to, during and following the five sprint bouts. RESULTS: Significant main effects (p < 0.001) were observed for sprint bout order in values of PP, MP, DEC, and HR. There were significant main effects detected for condition in PP and MP (p < 0.05), with values across the five sprint bouts 2.6 - 15% greater with GPLC. Significant statistical interactions were detected between bout order and condition for both PP and MP (p < 0.05). There was a significant main effect of condition for LAC, LAC values 15.7% lower 4 min post-exercise with GPLC (p = 0.09) and with GPLC resulting in 16.2% less LAC at 14 min post-exercise (p < 0.05). CONCLUSION: These findings indicate that short-term oral supplementation of GPLC can enhance peak power production in resistance trained males with significantly less LAC accumulation.

Effects of resistance and endurance training in persons with paraplegia.

INTRODUCTION: The specific effects of resistance and endurance training on upper extremity work capacity, muscular strength, and anaerobic power in chronic survivors of paraplegia have not been previously determined. PURPOSE: This study compared the effects of 12 wk of endurance training (ET) with 12 wk of resistance training (RT) on VO(2peak), upper extremity strength, and power output in persons with chronic paraplegia. METHODS: Eighteen subjects with neurologically complete paraplegia, T6-T10, participated in three weekly exercise sessions during a 12-wk training period. Subjects were matched into pairs (body mass and gender) and were randomly assigned to ET or RT. The ET group performed 30 min of arm cranking at 70%-85% of HR(peak). The RT group performed three sets of 10 repetitions at six exercise stations with an intensity of ranging from 60% to 70% of 1 repetition maximum (1RM). Values of upper extremity strength (1RM) were established using the Mayhew regression equation. VO(2peak) was determined during arm ergometry testing using open circuit spirometry. Arm Wingate anaerobic testing (WAnT) was used to determine subjects' peak and mean anaerobic power output. RESULTS: VO(2peak) values were significantly greater after RT (15.1%) and ET (11.8%). Muscular strength significantly increased for all exercise maneuvers in the RT group (P values < 0.01) with no changes detected in the ET group. Mean WAnT power increased in the RT and ET groups by 8% and 5%, respectively. The RT group displayed significantly greater gains in peak WAnT power (P < 0.001) than ET, 15.6% and 2.6%, respectively. CONCLUSION: Persons with paraplegia can significantly improve their upper extremity work capacity, muscular strength, and power by participating in RT.

Acute enhancement of lower-extremity dynamic strength and flexibility with whole-body vibration.

The purpose of this investigation was to examine the acute effects of whole-body vibration (WBV) on muscular strength, flexibility, and heart rate (HR). Twenty adults (10 men, 10 women) untrained to WBV participated in the study. All subjects completed assessment of lower-extremity isokinetic torque, flexibility, and HR immediately before and after 6 minutes of WBV and 6 minutes of leg cycling ergometry (CYL), in randomized order. During WBV, subjects stood upright on a vibration platform for a total of 6 minutes. Vibration frequency was gradually increased during the first minute to a frequency of 26 Hz, which was maintained for the remaining 5 minutes. During CYL, power output was gradually increased to 50 W during the first minute and maintained at that power output for the remaining 5 minutes. Lower-extremity flexibility was determined using the sit-and-reach box test. Peak and average isokinetic torque of knee extension and flexion were measured by means of a motor-driven dynamometer with velocity fixed at 120 degrees .s. Change scores for the outcome measures were compared between treatments using Student's paired t-tests. Analysis revealed significantly greater HR acceleration with CYL (24.7 bpm) than after WBV (15.8 bpm). The increase of sit-and-reach scores after WBV (4.7 cm) was statistically greater (p < 0.05) than after CYL (0.8 cm). After WBV, increases in peak and average isokinetic torque of knee extension, 7.7% and 9.6%, were statistically greater than after CYL (p < 0.05). Average torque of knee flexion also increased more with WBV (+7.8%) than with CYL (-1.5%) (p < 0.05). The findings of this study indicate that short-term WBV standing elicits acute enhancements of lower-extremity muscular torque and flexibility, suggesting the application of this technology as a preparatory activity before more intense exercise.

The acute effects of different durations of static stretching on dynamic balance performance.

The purpose of this study was to examine the effects of different durations of static stretching on dynamic balance. Women (N = 28) were tested before and after 2 stretching interventions and a control condition on 3 separate days, at least 48 hours apart. The stretching sessions involved a cycle ergometer warm-up at 70 rpm and 70 W followed by passive stretching of the lower-body muscles. Each stretching position was held at a point of mild discomfort and repeated 3 times with 15 seconds between stretches. In the 2 stretching protocols, the positions were maintained for 15 or 45 seconds. The control condition involved the same cycle ergometer warm-up, with a 26-minute rest period between pre- and posttests. Balance was assessed using the Biodex Balance System. A 2-way repeated-measures analysis of variance was used with the effects of study condition (control, 15 seconds, 45 seconds) and time (pre-, postscores). Post hoc paired t-tests were used when appropriate to determine possible statistical significance between pre- and posttest scores. Analyses indicated no significant main effects for either study condition or time. However, there was a significant condition x time interaction (p < 0.05). Post hoc analyses indicated that the 15-second condition produced a significant improvement in the balance scores (p < 0.01), with no significant effects with the control condition or the 45-second treatment. The results of this study reveal that a stretching protocol of 45-second hold durations does not adversely affect balance when using the current stabilometry testing procedure. Furthermore, a stretching intervention with 15-second hold durations may improve balance performance by decreasing postural instability. Strength and conditioning professionals concerned with reported performance limitations associated with static stretching should consider applying shorter-duration stretching protocols when aiming to improve balance performance.

New functional electrical stimulation approaches to standing and walking.

Spinal cord injury (SCI) is a devastating neurological trauma that is prevalent predominantly in young individuals. Several interventions in the areas of neuroregeneration, pharmacology and rehabilitation engineering/neuroscience are currently under investigation for restoring function after SCI. In this paper, we focus on the use of neuroprosthetic devices for restoring standing and ambulation as well as improving general health and wellness after SCI. Four neuroprosthetic approaches are discussed along with their demonstrated advantages and their future needs for improved clinical applicability. We first introduce surface functional electrical stimulation (FES) devices for restoring ambulation and highlight the importance of these devices for facilitating exercise activities and systemic physiological activation. Implanted muscle-based FES devices for restoring standing and walking that are currently undergoing clinical trials are then presented. The use of implanted peripheral nerve intraneural arrays of multi-site microelectrodes for providing fine and graded control of force during sit-to-stand maneuvers is subsequently demonstrated. Finally, intraspinal microstimulation (ISMS) of the lumbosacral spinal cord for restoring standing and walking is introduced and its results to date are presented. We conclude with a general discussion of the common needs of the neuroprosthetic devices presented in this paper and the improvements that may be incorporated in the future to advance their clinical utility and user satisfaction.

Exercise responses and adaptations in rowers and spinal cord injury individuals.

Elite rowers (ROWERS) and those who have had a spinal cord injury (SCI) are different physically in many realms. Both have physical activity histories that affect their lower-extremity extensor muscles in a dramatically different fashion. ROWERS can sustain a 500-W power output during their 5- to 6-min race. After a complete SCI, a 75-W power output might be achieved during a VO(2peak) test. Elite SCI wheelchair racers can achieve a higher value that is similar to that of a sedentary able-bodied person. ROWERS can attain a VO(2 max) of more than 7.5 L.min(-1) and can tolerate a blood lactate of 30 mmol.L(-1). After a complete SCI in which muscles become markedly atrophied, a peak VO(2) of 2 L.min(-1) and a blood lactate of 10 mmol.L(-1) might be achieved. ROWERS rely on the 75% slow-twitch fiber composition of their trained thigh muscles to train and race. Such activity modestly increases fiber size and markedly increases mitochondrial content. After a complete SCI, affected muscle fibers markedly atrophy, maintain most of their mitochondrial content, and become fast-twitch. These data suggest remarkable plasticity of physical function to the extreme that a marked increase in energy demanding, rather continuous physical activity can make a muscle more "slow-twitch"; so it will demand less energy when contracted. In contrast, SCI eventually causes muscle to be composed of more fast-twitch fibers. Molecular biologists may explain why fast-twitch fibers, which appear ideal for some athletes because of their high power output, are abundant in muscles that are seldom recruited. Until then, our results indicate that the fiber type composition of muscle in humans is stable unless extreme alterations in physical activity are endured.

Relation between muscular strength and cardiorespiratory fitness in people with thoracic-level paraplegia.

OBJECTIVES: To determine the relation between muscular strength, aerobic power (V O2 peak), submaximal blood lactate accumulation, and endurance performance in people with thoracic-level paraplegia. DESIGN: Participants performed tests of isokinetic strength, a graded exercise test, and 2 endurance performance tests. A Latin square counterbalanced design was used to determine the order of testing. SETTING: Research laboratory in a university setting. PARTICIPANTS: Ten adult male volunteers with thoracic-level paraplegia. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The relations between strength, V O2 peak, submaximal blood lactate accumulation, and endurance were determined by correlation analysis. RESULTS: Shoulder flexion strength correlated with V O2 peak and power output at V O2 peak. Shoulder strength accounted for 68.4% of the variation in performance time. Greater isokinetic elbow flexion and extension strength was associated with higher V O2 and power output at a blood lactate concentration of 4 mmol/L (flexion) and with a greater power output at V O2 peak (extension). CONCLUSIONS: These findings suggest that in this population, greater muscular strength is associated with greater aerobic power and endurance. Greater muscular strength could exert a positive influence on exercise performance by enabling higher levels of cardiorespiratory stress as the result of reduced or delayed local muscle fatigue.

Reliability of upper extremity anaerobic power assessment in persons with tetraplegia.

BACKGROUND/OBJECTIVE: Reliable assessment of upper extremity anaerobic power in persons with cervical spinal cord injury (SCI) may indicate the ability to successfully and safely perform many daily activities. PURPOSE: To examine test-retest reliability of upper extremity Wingate anaerobic testing (WAnT) in persons with motor/sensory complete tetraplegia. METHODS: Forty-five persons with cervical-level SCI (15 individuals each at C5, C6, and C7 levels of injury) performed 2-arm WAnT bouts, with 2 to 4 days between bouts. Subjects performed the WAnT seated in their wheelchairs using a tabletop-mounted Monarch 834E ergometer. Resistance loads were applied relative to injury level, with 1%, 2%, and 3% of body mass applied to subjects with C5, C6, and C7 level injuries, respectively. All subjects were directed to crank the ergometer at maximal velocity for a 30-second period. Values of peak power (Ppeak) and mean power (Pmean) were determined using an SMI OptoSensor 2000 system. Ppeak and Pmean were compared between trials and between groups using 2-way analyses of variance for repeated measures. Coefficients of determination (r2) were calculated between trials. RESULTS: There were no significant differences in Ppeak or Pmean detected between the 2 trials of WAnT in the C5, C6, or C7 groups. Regression analyses revealed statistically significant associations between bouts for Pmean and Ppeak in each of the 3 groups (P < 0.05). CONCLUSIONS: Upper extremity WAnT is reliable for upper extremity anaerobic power assessment in persons with cervical SCI at or below the C5 level.

Exercise recommendations for individuals with spinal cord injury.

Persons with spinal cord injury (SCI) exhibit deficits in volitional motor control and sensation that limit not only the performance of daily tasks but also the overall activity level of these persons. This population has been characterised as extremely sedentary with an increased incidence of secondary complications including diabetes mellitus, hypertension and atherogenic lipid profiles. As the daily lifestyle of the average person with SCI is without adequate stress for conditioning purposes, structured exercise activities must be added to the regular schedule if the individual is to reduce the likelihood of secondary complications and/or to enhance their physical capacity. The acute exercise responses and the capacity for exercise conditioning are directly related to the level and completeness of the spinal lesion. Appropriate exercise testing and training of persons with SCI should be based on the individual's exercise capacity as determined by accurate assessment of the spinal lesion. The standard means of classification of SCI is by application of the International Standards for Classification of Spinal Cord Injury, written by the Neurological Standards Committee of the American Spinal Injury Association. Individuals with complete spinal injuries at or above the fourth thoracic level generally exhibit dramatically diminished cardiac acceleration with maximal heart rates less than 130 beats/min. The work capacity of these persons will be limited by reductions in cardiac output and circulation to the exercising musculature. Persons with complete spinal lesions below the T(10) level will generally display injuries to the lower motor neurons within the lower extremities and, therefore, will not retain the capacity for neuromuscular activation by means of electrical stimulation. Persons with paraplegia also exhibit reduced exercise capacity and increased heart rate responses (compared with the non-disabled), which have been associated with circulatory limitations within the paralysed tissues. The recommendations for endurance and strength training in persons with SCI do not vary dramatically from the advice offered to the general population. Systems of functional electrical stimulation activate muscular contractions within the paralysed muscles of some persons with SCI. Coordinated patterns of stimulation allows purposeful exercise movements including recumbent cycling, rowing and upright ambulation. Exercise activity in persons with SCI is not without risks, with increased risks related to systemic dysfunction following the spinal injury. These individuals may exhibit an autonomic dysreflexia, significantly reduced bone density below the spinal lesion, joint contractures and/or thermal dysregulation. Persons with SCI can benefit greatly by participation in exercise activities, but those benefits can be enhanced and the relative risks may be reduced with accurate classification of the spinal injury.

Effect of variable loading in the determination of upper-limb anaerobic power in persons with tetraplegia.

This article examines the effects of levels of resistance loading during arm Wingate Anaerobic Testing (WAnT) in persons with differing levels of cervical spinal cord injury (SCI). Thirty-nine persons with motor-complete SCI tetraplegia (13 each at C5, C6, and C7) performed six bouts of arm-crank WAnT with relative loads equivalent to 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 percent of body mass (BM). Power output was determined with the use of the SMI OptoSensor 2000 (Sports Medicine Industries, Inc., St. Cloud, MN, USA) hardware and software package. Values of peak power (P(peak)) and mean power (P(mean)) were examined statistically between groups (C5, C6, and C7) and across levels of resistance loading. Resistance loads that provided the greatest values of P(mean) for the three groups were as follows: C5 = 1.0 or 1.5 percent of BM; C6 = 1.5 or 2.0 percent of BM; and C7 = 2.5, 3.0, or 3.5 percent of BM. Appropriate loading for arm WAnT is specific to the level of tetraplegia and may provide a useful assessment of upper limb power production.

Metabolic and cardiac responses to robotic-assisted locomotion in motor-complete tetraplegia: a case report.

BACKGROUND/OBJECTIVE: To examine acute metabolic responses to treadmill locomotion in a participant with motor-complete tetraplegia. METHODS: The participant--a woman with a chronic ASIA B C3-C4 spinal cord injury--walked on a treadmill with 40% body weight support (BWS) and robotic assistance. Oxygen consumption (VO2), minute ventilation (VE), and heart rate (HR) were measured during seated resting, supported standing, and 40 minutes of walking with stepping assistance from a Lokomat-driven gait orthosis. RESULTS: A resting VO2 equal to 50 milliliters per minute was predictably low, and did not change after the participant assumed an upright posture. Both VO2 and VE increased immediately upon onset of locomotion, suggesting a neurogenic rather than a humoral regulatory response to movement. VO2 averaged 2.4 metabolic units (METS) during locomotion at an average expenditure of 2.98 kilocalories per minute. HR was unaltered by standing, but during locomotion averaged 1 7 beats higher than during resting. Increases in VE but not VO2 upon standing, and decreases in VO2 but not VE immediately after walking, rule out changes in VE alone as the source for increased VO2 during walking. CONCLUSION: The data collected on this single participant show that treadmill locomotion with BWS and robotic assistance elicits a metabolic response to treadmill gaiting characterized by increased VO2, VE, HR, and caloric expenditure.

Combined hyperlipidemia in a single subject with tetraplegia: ineffective risk reduction after atorvastatin monotherapy.

BACKGROUND/OBJECTIVE: Effects of atorvastatin (Lipitor) drug monotherapy (10 mg daily) on fasting blood lipid profiles and cardiovascular disease (CVD) risks were examined for a single subject with C5-C6 tetraplegia. Routine fasting lipid profiles were analyzed by standard biochemistry techniques for total cholesterol (TC), triglycerides (TG), low-density lipoprotein-cholesterol (LDL-C), and high-density lipoprotein-cholesterol (HDL-C). Lipid profiles were analyzed on 3 occasions before drug therapy was initiated and 3 months after therapy commenced. The TC:HDL and LDL:HDL ratios were computed for all sampling times and used to assess pretreatment and post-treatment CVD risk. RESULTS: Fasting TC, TG, and LDL-C were all significantly reduced by therapy. The pretreatment HDL-C of 35 mg/dL was lowered to 21 mg/dL. As a result, the TC:HDL risk ratio was only marginally reduced from 6.6 to 6.4, whereas the LDL:HDL risk ratio remained unchanged by treatment. CONCLUSIONS: In this man with tetraplegia, atorvastatin drug monotherapy rapidly lowered TC, TG, LDL-C, and HDL-C. However, the TC:HDL ratio, considered the best predictor of CVD risk, was unchanged.