Reliability of an electrical method to induce muscle cramp.
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Biomedical subjects
Publications and source records attributed to Christopher D Ingersoll.
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OBJECTIVE: To determine the effects of a simulated knee joint effusion on center of pressure (COP) path and mean power frequency (MPF) during standing. DESIGN: Quasi-experimental design. SETTING: Sports injury research laboratory in a university setting. PARTICIPANTS: Twenty healthy volunteers, 10 of whom (age, 20.1+/-2.4y; height, 168.0+/-8.1cm; weight, 70.4+/-13.3kg) were assigned to an effusion group and 10 of whom (age, 25+/-3.8y; height, 169.4+/-8.9cm; weight, 74.7+/-7.7kg) were assigned to a control group. INTERVENTIONS: COP data were collected before and after a 60-mL injection of sterile saline into the knee joint space. MAIN OUTCOME MEASURES: COP path and mediolateral and anteroposterior MPF. RESULTS: COP path decreased after the effusion (pre-effusion mean, 92.2+/-21.9cm; posteffusion mean, 77.27+/-23.0cm). No change was found within the control group for COP path (P>.05). No differences were detected before or after joint effusion when the MPF was examined (P>.05). CONCLUSIONS: Possible explanations for the improved postural control after the effusion include additional somatosensory feedback, an augmented neural drive to the soleus, and/or increased capsular tension.
Measurement of the Hoffmann reflex (H-reflex) provides an estimate of alpha motoneuron activity in the target motoneuron (MN) pool. The H-reflex has been assessed for a wide variety of reasons in neuroscience research. However, the majority of protocols have focused on the assessment of only one muscle and its corresponding motoneuron pool at any instant. Previously established protocols do not simultaneously assess reflex activity in multiple muscles elicited from a single stimulation. This new protocol allows for assessment of alpha motoneuron activity in three muscles around the ankle joint from a single stimulus to the sciatic nerve. To elicit the responses, the sciatic nerve was stimulated just prior to its bifurcation into the tibial and common peroneal nerves in the popliteal fossa. Electromyographic recording electrodes were placed on the tibialis anterior, peroneal longus, and soleus muscles. The 1-ms square wave pulse was delivered every 15 s during the recruitment curve mapping. The maximum H reflex and M waves were measured in each muscle and their ratios calculated. The measurement of these ratios simultaneously allows for assessment of the cumulative alpha motoneuron activity about the ankle at a given point in time.
EGb 761 has been shown to increase acetylcholine synthesis and release and increase cholinergic receptors leading to an increase in cholinergic neurotransmission. These effects may be observed in the neuromuscular system, manifested by changes in motoneuron pool excitability as measured by the Hoffmann reflex to motor response (H/M) ratio. The objective was to determine whether a single dose of EGb 761 affects motoneuron pool excitability of the soleus muscle as measured by the H/M ratio. Following initial soleus H/M measurements, 20 healthy volunteers were randomly assigned to 1 of 3 treatment groups (control, 180 g cellulose placebo, and 180 g EGb 761). H/M ratios were recorded 1, 2, and 3 hours post treatment. A 3 x 4 repeated-measures analysis of variance was used to analyze differences in H/M ratio between treatments. No differences were observed between treatments (p = 0.75) or over time (p = 0.17), and there was not a treatment by time interaction (p = 0.27). A single dose of 180 g of EGb 761 does not affect soleus motoneuron pool excitability.
OBJECTIVE: To determine if differing subcutaneous adipose thickness alters the treatment duration required to produce a standard cooling effect during cryotherapy. DESIGN: A 4-group, between-groups comparison in which the independent variable was skinfold thickness (0-10mm, 11-20mm, 21-30mm, 31-40mm) and the dependent variable was cooling time, defined as the treatment duration required to decrease intramuscular (IM) temperature 7 degrees C from baseline. SETTING: A sports injury research laboratory. PARTICIPANTS: Forty-seven volunteers with anterior thigh skinfold measurement of less than 40mm. INTERVENTION: Topical cryotherapy (750g crushed-ice bag) to the anterior thigh to produce a typical cooling effect, defined as IM temperature at 1cm subadipose declining by 7 degrees C. MAIN OUTCOME MEASURE: Cryotherapy treatment duration required to produce a standardized cooling effect in subjects with differing subcutaneous adipose thickness. RESULTS: Analysis of variance revealed that mean time to cool IM tissues by 7 degrees C differed across all groups, with cooling time increasing as adipose thickness increased. The mean +/- standard deviation cooling times were as follows: 31-40mm (58.6+/-11.7min), 21-30mm (37.8+/-9.6min), 11-20mm (23.3+/-6.7min), and 0-10mm (8.0+/-3.4min). CONCLUSIONS: During cold application, there is a clinically important direct relationship between adipose thickness and required cooling time. This relationship necessitates dramatic adjustments to cryotherapy duration to produce similar IM temperature changes. A 25-minute treatment may be adequate for a patient with a skinfold of 20mm or less; however, a 40-minute application is required to produce similar results in a patients with skinfolds between 21 and 30mm, whereas a 60-minute application is required for patients with skinfolds of 30 to 40mm.
The Hoffman reflex (H-reflex) has been widely used throughout neuroscience research, as it allows for the assessment of alpha motoneuron excitability arising from a specific motoneuron pool. Recently, a protocol has been developed allowing for the simultaneous examination of the soleus, peroneal, and tibialis anterior motoneuron pools elicited from a single peripheral stimulus. In order for this protocol to be useful, the reliability of the measures must be established. The purpose of the current study was to determine the intersession reliability of the soleus, peroneal, and tibialis anterior H-reflexes and their corresponding M-waves elicited from a single stimulus to the sciatic nerve. Ten healthy neurologically sound individuals (age: 23 +/- 7 yrs; height: 175 +/- 12 cm; mass: 76 +/- 22 kg) volunteered to participate in this investigation. To obtain the measurements, the sciatic nerve was stimulated just prior to its bifurcation into the tibial and common peroneal nerves in the popliteal fossa. A 1-ms square wave pulse was delivered in 0.2 V increments until the maximum M wave was seen in each muscle. The maximum H-reflex and M-waves were collected from each muscle and their ratios calculated. Intersession reliability over 2 consecutive days was estimated using intraclass correlation coefficients (ICC [2.1]). Intersession reliability for the soleus Max H, Max M, and H:M ratio were 0.9953, 0.9514, and 0.9747, respectively. The peroneal reliability measurements were as follows: 0.9979 (Max H), 0.9924 (Max M), and 0.9664 (H:M ratio). Intersession reliability was 0.8591, 0.9968, and 0.7810 for the tibialis anterior Max H. Max M. and H:M ratio, respectively. These results indicate that the H-reflex measured from the soleus, peroneal, and tibialis anterior musculature elicited with a single peripheral stimulus to the sciatic nerve is reliable between sessions. This protocol allows the clinician/researcher to reliably investigate the alpha motoneuron excitability of multiple motoneuron pools about the ankle at a single point in time.
OBJECTIVE: The purpose of this study was to determine whether a common bromelain regimen or common ibuprofen regimen are effective in resolving pain and muscle dysfunction associated with delayed onset muscle soreness of the elbow flexors. DESIGN: A randomized, double-blinded, repeated measures design was used for this study. SETTING: The study was performed in the Sports Injury Research Lab at an NCAA Division I university. PARTICIPANTS: Forty subjects who had not participated in an upper body resistance-training program 3 months prior to the study, suffered pain or injury in the nondominant arm, or experienced an adverse response to nonsteroidal anti-inflammatory drugs or pineapple (bromelain source) were recruited. Thirty-nine subjects finished the study. INTERVENTIONS: Active range of motion (ROM), perceived pain, and peak concentric torque measurements of the nondominant arm were taken prior to and 24, 48, 72, and 96 hours following an eccentric exercise protocol of the elbow flexors. Subjects were assigned to one of four treatment groups (bromelain 300 mg t.i.d., ibuprofen 400 mg t.i.d., placebo t.i.d., and control) and began treatment immediately following the exercise protocol. MAIN OUTCOME MEASURES: No differences among treatments were observed for any of the dependent variables at any time. ROM deficits and pain peaked between 48 and 72 hours. Peak torque deficiencies were observed between 24 and 72 hours. CONCLUSIONS: Ingestion of bromelain and ibuprofen had no effect on elbow flexor pain, loss of ROM, or loss of concentric peak torque as a result of an eccentric exercise regimen.
STUDY DESIGN: A repeated-measures design was used. The independent variable was ultrasound coupling medium with 2 levels: gel pad and traditional gel. The dependent variable was peak intramuscular (IM) tissue temperature. OBJECTIVE: To compare changes in IM temperature during similar ultrasound treatments with 2 different coupling media. BACKGROUND: Gel pads are gaining popularity as an ultrasound coupling medium. Intramuscular temperatures during ultrasound with gel pads and standard gel have not been compared. METHODS AND MEASURES: Subjects were 13 student volunteers (21.3 +/- 1.4 years of age) without lower-extremity pathology. Ultrasound treatments were administered in a laboratory on two separate occasions 48 hours apart, each with a different coupling medium (standard ultrasound gel or gel pad). One-MHz continuous ultrasound was administered for 7 minutes at 1.5 W/cm2 with the transducer head moving 3 to 4 cm/s over an area approximately twice the size of the transducer head. Tissue temperature was measured every 10 seconds using implantable thermocouples inserted at a 3-cm depth to the surface of the right medial calf. Data were analyzed using an ANCOVA with pretreatment temperature as the covariate. RESULTS: Tissue temperatures increased during both treatments, with the mean and standard deviation peak temperature during the gel pad treatment reaching 39.40 +/- 1.5 degrees C compared to 39.20 +/- 2.4 degrees C during the normal gel treatment. Statistical analysis revealed no difference in temperature between ultrasound treatments using gel and those performed using gel pads. CONCLUSIONS: Because temperature changes were similar with both treatments, we conclude that these coupling methods are equivalent under the ultrasound application parameters tested.
OBJECTIVE: Arthrogenic muscle inhibition (AMI) is a presynaptic, ongoing reflex inhibition of joint musculature after distension or damage to the joint. The extent to which therapeutic interventions affect AMI is unknown. The purpose of this study was to verify that the vastus medialis (VM) is inhibited using the knee joint effusion model and to investigate the effects of cryotherapy and transcutaneous electric nerve stimulation (TENS) on AMI using this model. DESIGN AND SETTING: A 3 x 6 analysis of variance was used to compare Hoffmann-reflex data for treatment groups (cryotherapy, TENS, and control) across time (preinjection, postinjection, and 15, 30, 45, and 60 minutes after injection). SUBJECTS: Thirty neurologically sound volunteers (age = 21.8 +/- 2.4 years; height = 175.6 +/- 9.6 cm; mass = 71.5 +/- 13.3 kg) participated in this study. MEASUREMENTS: Hoffmann-reflex measurements were collected using a percutaneous stimulus to the femoral nerve and surface electromyography of the VM. RESULTS: Hoffmann-reflex measurements from the cryotherapy and TENS groups were greater than measurements from the control group at 15 and 30 minutes after injection. Measurements from the cryotherapy group were greater than for the TENS group, and measurements for the TENS group were greater than those for the control group at 45 minutes. At 60 minutes, the cryotherapy group measurements were greater than the TENS and control group measures. Measurements at 15, 30, 45, and 60 minutes after injection were reduced compared with the preinjection and postinjection measurements in the control group. Measurements in the cryotherapy group at 30, 45, and 60 minutes were greater than the preinjection, postinjection, and 15-minute data. No differences between time intervals existed in the TENS group. CONCLUSIONS: Artificial knee joint effusion results in VM inhibition. Cryotherapy and TENS both disinhibit the quadriceps after knee joint effusion, and cryotherapy further facilitates the quadriceps motoneuron pool. Cryotherapy treatment resulted in facilitation of the VM motoneuron pool during the post-treatment phase. The TENS treatment failed to disinhibit the VM motoneuron pool by 30 minutes postinjection.
OBJECTIVE: Wound care is a part of daily activity for many athletic trainers. Knowing which cleansers are effective against the bacteria that most commonly cause infection and whether they are toxic to healthy cells enables athletic trainers to make educated decisions on which cleanser to use. We compared the bactericidal effectiveness and cytotoxicity to human fibroblast cells of 4 cleansers at various dilutions. DESIGN AND SETTING: A 4 x 4 factorial design was used for the cytotoxicity testing. The independent variables were type and dilution of cleanser. The dependent variable was cell viability of the human fibroblast cells. We used a 2 x 3 x 4 x 4 factorial design for the bacterial testing. The independent variables were type and dilution of bacteria and type and dilution of cleanser. The dependent variable was the bactericidal action of the cleanser on the bacteria. SUBJECTS: Human foreskin samples were used to obtain a line of fibroblast cells. Bacterial samples were obtained from an athletic training clinic, isolated from swabs of a whirlpool water supply valve (Pseudomonas aeruginosa) or skin surface (Staphylococcus aureus). MEASUREMENTS: We obtained bactericidal measurements by testing isolated Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria. Minimum and maximum concentrations were identified according to bactericidal effectiveness. Cytotoxicity measurements were obtained from spectrophotometer readings of a neutral red assay for fibroblast cell viability. Final dilutions tested were determined by pilot testing. RESULTS: At the 1:5 dilution of product in sterile 0.9% saline, both Cinder Suds and Nitrotan and hydrogen peroxide were different from the control with regard to Pseudomonas aeruginosa. At the 1:10 dilution, both Betadine and hydrogen peroxide were different from the control with regard to Pseudomonas aeruginosa. These 2 cleansers were also different from each other. At the 1:10 dilution, only Betadine was not different from the control for the cytotoxicity testing. CONCLUSIONS: Betadine was both effective against bacteria and not harmful to human fibroblast cells at a 1:10 dilution of a commercially purchased solution.
OBJECTIVE: To provide a comprehensive review of the literature regarding the role of external ankle support on joint kinematics, joint kinetics, sensorimotor function, and functional performance. DATA SOURCES: We searched MEDLINE and SPORT Discus databases from 1960-2001 for the key words ankle bracing, ankle support, ankle taping, and ankle prophylaxes. We also used personal libraries based on our own research to complement the existing literature. DATA SYNTHESIS: The effects of external ankle support have been studied on a plethora of dependent measures. Here, we specifically discuss the role of external ankle support on joint kinematics, joint kinetics, sensorimotor function, and functional performance and present a general consensus regarding the overall effects of these prophylactic devices. CONCLUSIONS/RECOMMENDATIONS: The effects of ankle support on joint kinematics during static joint assessment and on traditional functional-performance measures (ie, agility, sprint speed, vertical jump height) are well understood. However, the potential effects of ankle support on joint kinetics, joint kinematics during dynamic activity (eg, a cutting maneuver), and various sensorimotor measures are not well known. Future research investigating the role of external ankle bracing needs to focus on these areas.
OBJECTIVE: To determine if the spectral qualities of medial-lateral (ML) and anterior-posterior (AP) center of pressure during a 1-legged stance are affected by 4 days of ankle-brace application. DESIGN AND SETTING: The study, which consisted of a pretest-posttest randomized group design, took place in the Sports Injury Research Laboratory at Indiana State University. SUBJECTS: Twenty-eight Indiana State University students, who had not suffered from any ankle injuries within the past 2 years and were free of any neurologic or vestibular disorders, participated in the study. MEASUREMENTS: The effects of 3 independent variables on mean frequency amplitude for both ML and AP center of pressure were examined: (1) treatment (brace, control), (2) frequency bin (0%-20%, 20%-40%, 40%-60%, 60%-80%, and 80%-100% of area), and (3) time (pretest, immediately after brace application, and after 1, 2, 3, or 4 days of brace wear). RESULTS: We detected no difference (P >.05) for the ML or AP mean frequency when comparing the brace and control groups. CONCLUSIONS: Application of an ankle brace may not require modifications in the postural-control strategies during a 1-legged stance in subjects with healthy ankles.
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