Physical Function, Gait, and Dynamic Balance of Transfemoral Amputees Using Two Mechanical Passive Prosthetic Knee Devices

Lythgo N, Marmaras B, Connor H. Physical function, gait, and dynamic balance of transfemoral amputees using two mechanical passive prosthetic knee devices.

Objective

To investigate the effect of the 3R90 and 3R92 (Otto Bock Healthcare) mechanical passive prosthetic knee devices on the physical function, gait, and dynamic balance (sudden stop and turn) of transfemoral amputees.

Design

Intervention study with crossover design.

Setting

University research center.

Participants

Men (N=5; mean age ± SD, 58.8±11.9y) with unilateral transfemoral amputation.

Intervention

Prosthetic knee joints (N=2; 3R90 and 3R92). Acclimatization ranged from 14 to 47 days (25.5±9.3d).

Main Outcome Measures

Physical function, gait, dynamic balance.

Results

The Timed Up and Go Test, 6-Minute Walk Test, and Four Square Step Test measures improved with the 3R92. Total scores on the Prosthesis Evaluation Questionnaire were similar for the 3R92 (82.0±6.3) and the participant's own or original device (83.9±4.8). These devices were rated higher than the 3R90 (65.5±16.8). Compared with the original device, gait velocity was significantly slower (5cm/s; P=.017) with the 3R92, but was unchanged for the 3R90. This difference was not considered clinically significant because the effect size was small (0.2). No other significant gait differences were found. Large temporal gait asymmetries observed with the original device remained with the 3R90 and 3R92 (step, ≈20%; single support, ≈30%; stance, ≈19%). Although no significant differences were found for the sudden-turn or sudden-stop tasks, the sudden-turn group success rates were highest with the original devices.

Conclusions

Gait and symmetry measures were unchanged. Gait speed was slower with the 3R92, but this was not considered to be clinically significant. Sudden-turn success rates generally were higher with the original devices. A crossover stepping movement was more difficult to implement than a side-stepping movement during sudden turns.     

Comparison of Trunk Proprioception Between Patients With Low Back Pain and Healthy Controls

Lee AS, Cholewicki J, Reeves NP, Zazulak BT, Mysliwiec LW. Comparison of trunk proprioception between patients with low back pain and healthy controls.

Objective

To determine whether proprioceptive impairments exist in patients with low back pain (LBP). We hypothesized that patients with LBP would exhibit larger trunk proprioception errors than healthy controls.

Design

Case-control study.

Setting

University laboratory.

Participants

24 patients with nonspecific LBP and 24 age-matched healthy controls.

Interventions

Not applicable.

Main Outcome Measures

We measured trunk proprioception in all 3 anatomical planes using motion perception threshold, active repositioning, and passive repositioning tests.

Results

LBP patients had significantly greater motion perception threshold than controls (P<.001) (1.3±0.9° vs 0.8±0.6°). Furthermore, all subjects had the largest motion perception threshold in the transverse plane (P<.001) (1.2±0.7° vs 1.0±0.8° for all other planes averaged). There was no significant difference between LBP and healthy control groups in the repositioning tasks. Errors in the active repositioning test were significantly smaller than in the passive repositioning test (P=.032) (1.9±1.2° vs 2.3±1.4°).

Conclusions

These findings suggest that impairments in proprioception may be detected in patients with LBP when assessed with a motion perception threshold measure.     

No Effects of Whole-Body Vibration Training on Muscle Strength and Gait Performance in Persons With Late Effects of Polio: A Pilot Study

Brogårdh C, Flansbjer U-B, Lexell J. No effects of whole-body vibration training on muscle strength and gait performance in people with late effects of polio: a pilot study.

Objective

To evaluate the feasibility and possible effects of whole-body vibration (WBV) training on muscle strength and gait performance in people with late effects of polio.

Design

A case-controlled pilot study with assessments before and after training.

Setting

A university hospital rehabilitation department.

Participants

People (N=5; 3 men, 2 women; mean age, 64±6.7y; range, 55−71y) with clinically and electrophysiologically verified late effects of polio.

Interventions

All participants underwent 10 sessions of supervised WBV training (standing with knees flexed 40°−55° up to 60 seconds per repetition and 10 repetitions per session twice weekly for 5 weeks).

Main Outcome Measures

Isokinetic and isometric knee muscle strength (dynamometer), and gait performance (Timed Up & Go, Comfortable Gait Speed, Fast Gait Speed, and six-minute walk tests).

Results

All participants completed the 5 weeks of WBV training, with no discernible discomfort. No significant changes in knee muscle strength or gait performance were found after the WBV training period.

Conclusions

This pilot study did not show any significant improvements in knee muscle strength and gait performance following a standard protocol of WBV training. Thus, the results do not lend support to WBV training for people with late effects of polio.     

Changes in Passive Mechanical Properties of the Gastrocnemius Muscle at the Muscle Fascicle and Joint Levels in Stroke Survivors

Gao F, Grant TH, Roth EJ, Zhang L-Q. Changes in passive mechanical properties of the gastrocnemius muscle at the muscle fascicle and joint levels in stroke survivors.

Objectives

To investigate the ankle joint-level and muscle fascicle-level changes and their correlations in stroke survivors with spasticity, contracture, and/or muscle weakness at the ankle.

Design

To investigate the fascicular changes of the medial gastrocnemius muscle using ultrasonography and the biomechanical changes at the ankle joint across 0°, 30°, 60°, and 90° knee flexion in a case-control manner.

Setting

Research laboratory in a rehabilitation hospital.

Participants

Stroke survivors (n=10) with ankle spasticity/contracture and healthy control subjects (n=10).

Interventions

Not applicable.

Main Outcome Measurements

At the muscle fascicle level, medial gastrocnemius muscle architecture including the fascicular length, pennation angle, and thickness were evaluated in vivo with the knee and ankle flexion changed systematically. At the joint level, the ankle range of motion (ROM) and stiffness were determined across the range of 0° to 90° knee flexion.

Results

At comparable joint positions, stroke survivors showed reduced muscle fascicle length, especially in ankle dorsiflexion (P≤.048) and smaller pennation angle, especially for more extended knee positions (P≤.049) than those of healthy control subjects. At comparable passive gastrocnemius force, stroke survivors showed higher fascicular stiffness (P≤.044) and shorter fascicle length (P≤.025) than controls. The fascicle-level changes of decreased muscle fascicle length and pennation angle and increased medial gastrocnemius fascicle stiffness in stroke were correlated with the joint level changes of increased joint stiffness and decreased ROM (P<.05).

Conclusions

This study evaluated specific muscle fascicular changes as mechanisms underlying spasticity, contracture, and joint-level impairments, which may help improve stroke rehabilitation and outcome evaluation.     

Proprioceptive acuity in active rotation movements in healthy knees

Muaidi QI, Nicholson LL, Refshauge KM. Proprioceptive acuity in active rotation movements in healthy knees.

Objectives

To investigate the ability of asymptomatic participants to discriminate between active knee rotation movements of different magnitude and to determine whether proprioceptive acuity of active knee rotation differs between limbs (dominant and nondominant and right and left).

Design

Cross-sectional study.

Setting

Laboratory in an Australian university.

Participants

Healthy volunteers (N=30) without previous cruciate ligament injury or surgery, previous fracture of the lower limbs, or other lower-limb disorders in the last 3 months.

Interventions

Not applicable.

Main Outcome Measures

Knee rotation proprioceptive acuity was determined by using our custom-designed device. The measure of proprioceptive acuity used in this study was the just-noticeable difference (JND). Participants actively rotated the knee (internal or external rotation) to 1 of 4 movement blocks and judged the magnitude of the permitted motion. Proprioceptive acuity scores, representing a participant’s ability to detect small differences in magnitude of active knee rotation movements, were then calculated.

Results

The means of the JND for proprioceptive acuity of internal rotation (1.37°±.11°) were significantly (P=.04) lower than for external rotation (1.6°±.14°) regardless of side (right, left) or dominance. No significant difference was found between the mean JND for left and right knee rotations (P=.84) or between the mean JND for dominant and nondominant knee rotation (P=.69).

Conclusions

Participants perceived smaller differences between active internal rotation movements than external rotation. No significant difference was found between the dominant and nondominant leg or between the left and right leg; therefore, clinicians can establish whether a proprioceptive deficit exists after unilateral injury and can use acuity of the uninjured knee as a normal status for rehabilitation.     

Comparison of surface cooling and invasive cooling for rapid induction of mild therapeutic hypothermia in pigs--effectiveness of two different devices

Aim of the study

The effectiveness and safety of non-invasive surface cooling was compared to invasive endovascular cooling in an animal model.

Methods

Eight healthy pigs (29-38 kg) were cooled twice, starting in the first 4 pigs with unique surface cooling pads followed by endovascular cooling. In the second 4 pigs the order was reversed. The goal was to quickly lower pulmonary artery temperature from 38 to 33 °C. A paired t-test was used to compare cooling rates (°C/h, mean ± standard deviation) between both cooling techniques.

Results

Mean non-invasive surface cooling rate (11.9 ± 3.8 °C/h) significantly exceeded mean invasive cooling rate (3.9 ± 0.7 °C/h; p < 0.001). The mean difference in cooling rates was 8.0 ± 3.6 °C/h. No surface cooling related adverse skin reactions were observed.

Conclusions

Surface cooling is a simple method for achieving fast cooling rates. In our animal model, non-invasive cooling was three times faster than rapid endovascular cooling without overshoot.     

Effect of botulinum toxin injection on length and lengthening velocity of rectus femoris during gait in hemiparetic patients

Background

In hemiparetic patients, rectus femoris spasticity is one of the main causes of reduced knee flexion in swing phase, known as stiff knee gait. Botulinum toxin is often used to reduce rectus femoris spasticity and to increase knee flexion during swing phase. However, the mechanisms behind these improvements remain poorly understood. The aim of this study was (1) to quantify maximal rectus femoris length and lengthening velocity during gait in ten adult hemiparetic subjects with rectus femoris spasticity and stiff knee gait and to compare these parameters with those of ten healthy subjects and (2) to study the effect of botulinum toxin injection in the rectus femoris muscle on the same parameters.

Methods

10 patients with stiff knee gait and rectus femoris spasticity underwent 3D gait analysis before and one month after botulinum toxin injection of the rectus femoris (200 U Botox®, Allergan Inc., Markham, Ontario, CANADA). Rectus femoris length and lengthening velocity were quantified using a musculoskeletal model (SIMM®, MusculoGraphics, Inc., Santa Rosa, California, USA).

Findings

Maximal length and lengthening velocity of the rectus femoris were significantly reduced on the paretic side. There was a significant increase in muscle length as well as lengthening velocity during gait following botulinum toxin injection.

Interpretation

This study showed that botulinum toxin injection in the spastic rectus femoris of hemiparetic patients improves muscle kinematics during gait. However maximal rectus femoris length did not reach normal values following injection, suggesting that other mechanisms are likely involved.     

Functional Electrical Stimulation to Dorsiflexors and Plantar Flexors During Gait to Improve Walking in Adults With Chronic Hemiplegia

Embrey DG, Holtz SL, Alon G, Brandsma BA, McCoy SW. Functional electrical stimulation to dorsiflexors and plantar flexors during gait to improve walking in adults with chronic hemiplegia.

Objective

To determine whether functional electrical stimulation (FES) timed to activate the dorsiflexors and plantar flexors during gait improves the walking of adults with hemiplegia.

Design

Randomized crossover trial.

Setting

Outpatient rehabilitation clinic.

Participants

Adults with hemiplegia (N=28) with a mean age ± SD of 60±10.9 years and 4.9±3.8 years postincident.

Interventions

Intervention “A” included 3 months of wearing the FES system, which activated automatically during walking for 6 to 8h/d, 7d/wk, plus walking 1h/d, 6d/wk. Intervention “B” included 3 months of walking 1h/d, 6d/wk without FES. Of the 28 patients who completed the study, 15 were randomly assigned to group A-B, 13 to group B-A. Crossover occurred at 3 months.

Main Outcome Measures

Variables were measured at pretreatment, 3 months, and 6 months. Three primary outcomes were selected a priori and included 2 functional variables, the 6-minute walk test and the Emory Functional Ambulatory Profile, and 1 participation variable, the Stroke Impact Scale. Secondary impairment measures included muscle strength and spasticity. Assessments were done without electrical stimulation.

Results

In phase 1, patients who received treatment A (A-B group) showed improvement compared with patients who received treatment B (B-A group) on the 6-minute walk test (P=.02), Emory Functional Ambulatory Profile (P=.08), and Stroke Impact Scale (P=.03). In phase 2, the A-B group maintained improvement in all 3 primary outcomes even without FES. Both groups improved significantly on all primary outcome measures, comparing 6-month to initial measures (P≤.05).

Conclusions

An FES system that stimulates dorsiflexors and plantar flexors similar to the timing of typical adult gait, combined with daily walking, can improve the walking ability of adults with hemiplegia.     

Therapeutic hypothermia after cardiac arrest: A retrospective comparison of surface and endovascular cooling techniques

Objectives

Therapeutic hypothermia (32-34 °C) is recommended for comatose survivors of cardiac arrest; however, the optimal technique for cooling is unknown. We aimed to compare therapeutic hypothermia using either surface or endovascular techniques in terms of efficacy, complications and outcome.

Design

Retrospective cohort study.

Setting

Thirty-bed teaching hospital intensive care unit (ICU).

Patients

All patients (n = 83) undergoing therapeutic hypothermia following cardiac arrest over a 2.5-year period. The mean age was 61 ± 16 years; 88% of arrests occurred out of hospital, and 64% were ventricular fibrillation/tachycardia.

Interventions

Therapeutic hypothermia was initiated in the ICU using iced Hartmann's solution, followed by either surface (n = 41) or endovascular (n = 42) cooling; choice of technique was based upon endovascular device availability. The target temperature was 32-34 °C for 12-24 h, followed by rewarming at a rate of 0.25 °C h⁻¹.

Measurements and main results

Endovascular cooling provided a longer time within the target temperature range (p = 0.02), less temperature fluctuation (p = 0.003), better control during rewarming (0.04), and a lower 48-h temperature load (p = 0.008). Endovascular cooling also produced less cooling-associated complications in terms of both overcooling (p = 0.05) and failure to reach the target temperature (p = 0.04). After adjustment for known confounders, there were no differences in outcome between the groups in terms of ICU or hospital mortality, ventilator free days and neurological outcome.

Conclusion

Endovascular cooling provides better temperature management than surface cooling, as well as a more favorable complication profile. The equivalence in outcome suggested by this small study requires confirmation in a randomized trial.     

Effects of ankle joint mobilizations in adults poststroke: a pilot study

Kluding PM, Santos M. Effects of ankle joint mobilizations in adults poststroke: a pilot study.

Objective

To compare the effect of 2 interventions on ankle mobility, ankle kinematics, and weight-bearing symmetry during functional activities in subjects with hemiparesis after a stroke.

Design

Randomized trial.

Setting

Academic medical center.

Participants

A convenience sample of 16 subjects with hemiparesis after stroke (mean age, 55.2y; mean time since stroke, 21.4mo).

Intervention

Subjects received 8 sessions over 4 weeks of either functional task practice combined with ankle joint mobilizations, or functional task practice only.

Main Outcome Measures

Changes in ankle range of motion (ROM) (not blinded), ankle kinematics during sit-to-stand (STS) and gait, and lower-extremity weight-bearing symmetry during STS and static standing.

Results

The combined intervention group gained 5.7°±3.1° in passive ankle ROM compared with 0.2°±2.6° in the functional practice only group (95% confidence interval [CI], 2.5-8.6; P<.01). No significant changes in ankle kinematics or weight bearing during static standing were noted in either group. The functional practice group decreased differences in weight bearing during STS by 9.5%±6.47%, whereas the combined intervention group increased this difference by 3.37%±5.29% (95% CI, 3.26-19.46; P=.01).

Conclusions

The increase in ankle motion did not improve joint kinematics and may have prevented improvement in weight-bearing symmetry.     

Gait Analysis for Evaluating the Relationship Between Increased Signal Intensity on T2-Weighted Magnetic Resonance Imaging and Gait Function in Cervical Spondylotic Myelopathy

Kim CR, Yoo JY, Lee SH, Lee DH, Rhim SC. Gait analysis for evaluating the relationship between increased signal intensity on T2-weighted magnetic resonance imaging and gait function in cervical spondylotic myelopathy.

Objective

To determine relationships between increased signal intensity (ISI) on T2-weighted cervical spine magnetic resonance imaging (MRI) and parameters of gait analysis in patients with cervical spondylotic myelopathy (CSM).

Design

Retrospective comparative study.

Setting

Gait analysis laboratory.

Participants

Patients (N=36) who undertook cervical laminectomy or laminoplasty because of CSM.

Interventions

Not applicable.

Main Outcome Measures

Subjects were evaluated by using the modified Japanese Orthopaedic Association (JOA) scale, the Nurick scale, cervical spine MRI, and gait analysis. Two radiologists classified patients into 3 groups: intense, faint, and no ISI.

Results

Relative to patients without ISI, those with ISI showed significantly slower gait speed, longer step time, decreased single-limb support time, increased double-limb support time, and limited range of motion of knee and ankle (P<.05). Increased intensity tended to correlate with poor gait function including slower gait speed, longer step time, decreased single-limb support time, and increased double-limb support time. The modified JOA and Nurick scale did not correlate with ISI.

Conclusions

In patients with CSM who received surgical treatment, more intense ISI on T2-weighted MRI correlated preoperatively with increased difficulties in gait function. Gait analysis may be a useful tool for evaluating gait functions in cervical myelopathy.     

Bilateral frontal plane mechanics after unilateral total knee arthroplasty

Milner CE, O'Bryan ME. Bilateral frontal plane mechanics after unilateral total knee arthroplasty.

Objective

To compare frontal plane knee mechanics among the operated and nonoperated limbs after total knee arthroplasty (TKA) and a healthy control limb.

Design

A cross-sectional analysis with age-matched control group.

Setting

A biomechanics and sports medicine laboratory.

Participants

Subjects (n=16; 8 men, 8 women; mean age, 61±7y; height, 1.71±0.10m; weight, 87.5±15.1kg) and age-matched healthy controls (n=16; 8 men, 8 women; mean age, 63±7y; height, 1.7±.09m; weight 72.5±13.9kg).

Interventions

Not applicable.

Main Outcome Measures

Peak knee adduction angle, first peak knee adduction moment, and the frontal plane knee angle and moment at loading peak during the stance phase of walking.

Results

Peak knee adduction angle (P=.176), and the frontal plane knee angle (P=.116) and moment (P=.260) at loading peak were similar across the operated, nonoperated, and healthy control limbs. The first peak knee adduction moment was higher in the nonoperated limb when compared with the operated limb and with the healthy control (P=.003). First peak knee adduction moment was similar in the operated knee and the healthy control.

Conclusions

The greater first peak knee adduction moment in the nonoperated knee indicates a possible mechanism for the predictable deterioration of this knee after unilateral TKA of the contralateral knee.     

Age-related differences in Tai Chi gait kinematics and leg muscle electromyography: a pilot study

Wu G. Age-related differences in Tai Chi gait kinematics and leg muscle electromyography: a pilot study.

Objective

To compare the biomechanic features of Tai Chi gait by elders with those by young adults, and with those of normative gait.

Design

Cross-sectional study.

Setting

Laboratory-based testing.

Participants

Young (n=6; 3 women) and old (n=6; 5 women) Tai Chi practitioners.

Intervention

All subjects had practiced Tai Chi for at least 4 months.

Main Outcome Measures

Spatial, temporal, and leg muscle electromyography during Tai Chi gait and normative gait.

Results

The primary age-related differences in Tai Chi gait were during single stance, with elders having significantly shorter single-stance time (−50%), less lateral displacement (-30%), knee flexion (-42%), hip flexion (-39%), activation time in the tibialis anterior (-13%), soleus (-39%), and tensor fascia lata (TFL) (-21%), activation magnitude in the tibialis anterior (-39%), and coactivation time of the tibialis anterior and soleus (-47%). Compared with normative gait, elders during Tai Chi gait had significantly larger knee (139%) and hip (66%) flexions, longer duration (90%-170%) and higher magnitude (200%-400%) of the tibialis anterior, rectus femoris, and TFL muscle activities, and longer duration of coactivation of most leg muscle pairs (130%-380%).

Conclusions

The elders practice Tai Chi gait in higher posture than younger subjects. The Tai Chi gait poses significantly higher challenges to elder’s balance and muscular system than does their normative gait.     

The effects of hip and ankle stretching on gait function of older people

Christiansen CL. The effects of hip and ankle stretching on gait function of older people.

Objective

To examine effects of hip and ankle stretching on gait function of older people.

Design

Randomized controlled trial.

Setting

Flexibility training was performed in participants' homes. Assessments were performed in a biomechanics laboratory.

Participants

Forty healthy volunteers (mean age ± SD, 72.1±4.7y) randomized to 2 groups: intervention (n=20) and control (n=20).

Intervention

Intervention participants performed an 8-week stretching program, and control group participants maintained activity level for 8 weeks. One investigator made weekly visits to instruct and monitor participants.

Main Outcome Measures

Primary outcome measures were passive joint motion for hip extension and ankle dorsiflexion and freely chosen gait speed. Secondary outcome measures were gait parameters during freely chosen gait speed and set gait speed walking (stride length, joint displacement).

Results

Compared with the control group, the intervention group had increased combined hip and knee motion (P=.023), ankle motion (P=.020), and freely chosen gait speed (P=.016). The intervention group showed statistically nonsignificant trends of increased stride length at freely chosen gait speed and set gait speed.

Conclusions

Findings suggest joint motion is a modifiable impairment that is effectively targeted with flexibility training for older people. Participants in the intervention group had improvements in joint motion as well as increased freely chosen gait speed. Mechanisms responsible for changes in freely chosen gait speed warrant further investigation.     

Botulinum Toxin Dilution and Endplate Targeting in Spasticity: A Double-Blind Controlled Study

Gracies J-M, Lugassy M, Weisz DJ, Vecchio M, Flanagan S, Simpson DM. Botulinum toxin dilution and endplate targeting in spasticity: a double-blind controlled study.

Objective

To determine the effects of botulinum neurotoxin type A (BTX-A) dilution and endplate-targeting in spastic elbow flexors.

Design

Double blind randomized controlled trial; 4-month follow-up after a 160-unit injection of BTX-A into spastic biceps brachii (4 sites). Randomization into: group 1: 100 mouse units (MU)/mL dilution, 0.4cc/site, 4-quadrant injection; group 2: 100MU/mL dilution, 0.4cc/site, 4 sites along endplate band; group 3: 20MU/mL dilution, 2cc/site, 4-quadrant injection (n=7 per group).

Setting

Institutional tertiary care ambulatory clinic.

Participants

Referred sample of 21 adults with spastic hemiparesis. No participant withdrew due to adverse effects.

Intervention

A 160-unit injection of BTX-A of different dilutions and locations into biceps brachii.

Main Outcome Measures

Primary: agonist and antagonist (cocontraction) mean rectified voltage (MRV) of elbow flexors/extensors during maximal isometric flexion/extension; secondary: maximal voluntary power of elbow flexion/extension; spasticity angle and grade in elbow flexors/extensors (Tardieu Scale); active range of elbow extension/flexion.

Results

BTX-A injection overall reduced agonist flexor MRV (-47.5%, P<0.0001), antagonist flexor MRV (-12%, P=.037), antagonist extensor MRV (-19%, P<.01), flexion maximal voluntary power (-33%, P<.001), elbow flexor spasticity angle (-30%, P<.001) and grade (-17%, P=.03), and increased extension maximal voluntary power (24%, P=.037) and active range of elbow extension (5.5%, 8°, P=.002). Agonist and antagonist flexor MRV reductions in group 3 (-81% and -31%) were greater than in groups 1 and 2, whereas increase in active range of elbow extension was greater in group 2 (10%) than in groups 1 and 3 (P<.05, analysis of covariance [ANCOVA]). Elbow flexor spasticity was significantly reduced in groups 2 and 3 only (P<.05, ANCOVA).

Conclusions

In spastic biceps, high-volume or endplate-targeted BTX-A injections achieve greater neuromuscular blockade, cocontraction and spasticity reduction, and active range of elbow extension improvement, than low volume, nontargeted injections.     

Quality of proteins in riboflavin and UV light-treated FFP during 1 year of storage at −18 °C

Background

The Mirasol® Pathogen Reduction Technology (PRT) System for plasma combines riboflavin (vitamin B₂) and UV light energy to reduce pathogens in plasma products. This study evaluated protein quality of apheresis derived plasma products treated with riboflavin and UV light and stored at −18 °C for up to 1 year. Comparisons were made to paired, untreated controls after 6 months and 1 year of storage.

Methods

This study evaluated the in vitro protein quality of apheresis derived plasma products processed between 8 and 8.5 h from collection and stored at −18 °C for 6 months and 1 year. Plasma (205 ± 5 mL) was combined with 35 ± 5 mL of 500 μM riboflavin, and exposed to UV light (6.24 J/mL). A total of 14 plasma units were used for this study. Plasma units were analyzed using standard coagulation assays immediately following treatment, and after 6 months and 1 year of storage at −18 °C.

Results

Fibrinogen, Total protein, Factors II, VIII, IX, X and XII were modestly affected by storage for 1 year at −18 °C. The average percent protein retention in treated plasma samples after 1 year of storage in comparison to controls held under similar conditions were: Total Protein, 103%, Factor II, 88%, Factors VII and XI, 62%, Factor V 60%, Factor VIII and IX, 77%, Fibrinogen, 75%, Factor X, 85% and Factor XII, 82%.

Conclusion

Results after 6 months (double the EU guidelines recommended storage time) and 1 year (four times longer than the EU guidelines recommended storage time) of storage at −18 °C demonstrated that all proteins were well preserved. Values observed for treated products stored under these conditions are within the same range as those reported for other pathogen inactivated plasma products.     

A method to measure the accuracy of loads in knee-ankle-foot orthoses using conventional gait analysis, applied to persons with poliomyelitis

Andrysek J, Redekop S, Matsui NC, Kooy J, Hubbard S. A method to measure the accuracy of loads in knee-ankle-foot orthoses using conventional gait analysis, applied to persons with poliomyelitis.

Objectives

To determine (1) the forces and moments passing through knee-ankle-foot orthoses (KAFOs) during walking and (2) the accuracy with which these loads can be measured using conventional gait analysis techniques.

Design

Comparative case series.

Setting

Rehabilitation facility with human movement laboratory (gait lab).

Participants

Four patients with poliomyelitis wearing KAFOs.

Interventions

KAFOs were instrumented with a load cell, and walking data were concurrently collected using conventional gait analysis.

Main Outcome Measures

Load measurements and gait parameters.

Results

Predominant orthotic loads (knee joint forces and moments) were composed of knee flexion moments and axial compression forces. With conventional gait analysis, peak knee joint moments were substantially underestimated compared with those directly measured using the load cell. Defining the knee axis anatomically versus at the orthotic axis, tracking it dynamically, and compensating for each patient's corrected knee flexion contracture resulted in considerable improvements in the gait lab estimates of knee joint moments.

Conclusions

A practical method that directly measures moments and forces in conventional KAFOs has been applied to show that conventional gait analysis techniques substantially underestimate knee joint moments in the KAFOs of persons with poliomyelitis. Underestimation of orthotic loads could result in underdesigned orthotic components and ultimately higher incidence of component failure in clinical applications.     

The effectiveness of progressively increasing stimulation frequency and intensity to maintain paralyzed muscle force during repetitive activation in persons with spinal cord injury

Chou L-W, Lee SC, Johnston TE, Binder-Macleod SA. The effectiveness of progressively increasing stimulation frequency and intensity to maintain paralyzed muscle force during repetitive activation in persons with spinal cord injury.

Objective

To compare the effectiveness of progressively increasing stimulation intensity, progressively increasing frequency, or progressively increasing both frequency and intensity on paralyzed quadriceps femoris muscle force maintenance during repetitive activation.

Design

Factorial design with different stimulation protocols as independent variables.

Setting

A muscle performance laboratory.

Participants

People (N=8) with spinal cord injury (SCI) (age, 14.63±1.77y).

Interventions

Not applicable.

Main Outcome Measure

Number of contractions when the peak force was 90% or more of a subject's maximal twitch force.

Results

The protocol involving progressively increasing stimulation intensity and then frequency generated more successful contractions (189.88±53.33) than progressively increasing the frequency followed by intensity (122.75±26.56 contractions). Regardless of the order, progressively increasing both intensity and frequency generated more successful contractions than progressively increasing intensity (97 contractions) or frequency (62 contractions) alone.

Conclusions

Our findings suggest that during repetitive electric activation, progressively increasing both stimulation frequency and intensity can produce more successful contractions than progressively increasing only frequency or intensity. These findings can help researchers and clinicians design more effective stimulation protocols for persons with SCI during functional electric stimulation applications.     

Increased EMG response following electromyographic biofeedback treatment of rectus femoris muscle after spinal cord injury

Objective

To study increases in electromyographic (EMG) response from the right and left rectus femoris muscles of individuals with long-term cervical spinal cord injuries after EMG biofeedback treatment.

Design

Repeated measure trials compared EMG responses before and after biofeedback treatment in patients with spinal cord injuries.

Main outcome measures

The Neuroeducator was used to analyse and provide feedback of the EMG signal and to measure EMG response.

Setting

Department of Traumatic Orthopaedics, School of Medicine, University of São Paulo, Brazil.

Participants

Twenty subjects (three men and 17 women), between 21 and 49 years of age, with incomplete spinal cord injury at level C6 or higher (range C2 to C6). Of these subjects, 10 received their spinal cord injuries from motor vehicle accidents, one from a gunshot, five from diving, three from falls and one from spinal disc herniation.

Results

Significant differences were found in the EMG response of the right rectus femoris muscle between pre-initial (T1), post-initial (T2) and additional (T3) biofeedback treatment with the subjects in a sitting position [mean (standard deviation) T1: 26 μV (29); T2: 67 μV (50); T3: 77 μV (62)]. The mean differences and 95% confidence intervals for these comparisons were as follows: T1 to T2, −40.7 (−53.1 to −29.4); T2 to T3, −9.6 (−26.1 to 2.3). Similar differences were found for the left leg in a sitting position and for both legs in the sit-to-stand condition.

Conclusions

The EMG responses obtained in this study showed that treatment involving EMG biofeedback significantly increased voluntary EMG responses from right and left rectus femoris muscles in individuals with spinal cord injuries.