Initial electrical stimulation frequency and cramp threshold frequency and force.

Context: In the electrically induced cramp model, the tibial nerve is stimulated at an initial frequency of 4 Hz with increases in 2-Hz increments until the flexor hallucis brevis cramps. The frequency at which cramping occurs (ie, threshold frequency [TF]) can vary considerably. A potential limitation is that multiple subthreshold stimulations before TF might induce fatigue, which is operationally defined as a decrease in maximal voluntary isometric contraction (MVIC) force, thereby biasing TF.

Production of consistent pain by intermittent infusion of sterile 5% hypertonic saline, followed by decrease of pain with cryotherapy.

Context: It is suggested that postinjury pain is difficult to examine; thus, investigators have developed experimental pain models. To minimize pain, cryotherapy (cryo) is applied, but reports on its effectiveness are limited.

Objective: To investigate a pain model for the anterior knee and examine cryo in reducing the pain.

Skinfold thickness at 8 common cryotherapy sites in various athletic populations.

Context: Researchers have observed slower cooling rates in thigh muscle with greater overlying adipose tissue, suggesting that cryotherapy duration should be based on the adipose thickness of the treatment site. Skinfold data do not exist for other common cryotherapy sites, and no one has reported how those skinfolds might vary because of physical activity level or sex.

Objective: To determine the variability in skinfold thickness among common cryotherapy sites relative to sex and activity level (National Collegiate Athletic Association Division I athletes, recreationally active college athletes).

Duration of electrically induced muscle cramp increased by increasing stimulation frequency.

Context: Electrically induced muscle cramps (EIMC) do not last long enough to study many cramp treatments. Increasing stimulation frequency lengthens cramp duration; it is unknown which frequency elicits the longest EIMC.

Objective: To determine which stimulation frequency elicits the longest EIMC and whether cramp duration and stimulation frequency are correlated.

Temperature measurement reliability and validity with thermocouple extension leads or changing lead temperature.

Context: Thermocouples' leads are often too short, necessitating the use of an extension lead.

Objective: To determine if temperature measures were influenced by extension-lead use or lead temperature changes.

Design: Descriptive laboratory study.

Gastric emptying after pickle-juice ingestion in rested, euhydrated humans.

Context: Small volumes of pickle juice (PJ) relieve muscle cramps within 85 seconds of ingestion without significantly affecting plasma variables. This effect may be neurologic rather than metabolic. Understanding PJ's gastric emptying would help to strengthen this theory.

Response of thermocouples interfaced to electrothermometers when immersed in 5 water bath temperatures.

Context: Thermocouples and electrothermometers are used in therapeutic modality research. Until recently, researchers assumed that these instruments were valid and reliable.

Objective: To examine 3 different thermocouple types in 5 degrees C, 15 degrees C, 18.

Temperature increases in the human achilles tendon during ultrasound treatments with commercial ultrasound gel and full-thickness and half-thickness gel pads.

Context: Although originally manufactured for use in diagnostic imaging of internal structures, 2-cm-thick gel pads are also used as conducting media for therapeutic ultrasound over areas with bony prominences. Research on the ability of these pads to conduct enough energy to adequately heat tissues has provided mixed results. However, this research has mainly been performed on the triceps surae muscle, an area over which gel pads are not typically used.

Three percent hypohydration does not affect threshold frequency of electrically induced cramps.

Purpose: Dehydration is hypothesized to cause exercise-associated muscle cramps. The theory states that dehydration contracts the interstitial space, thereby increasing the pressure on nerve terminals and cramps ensue. Research supporting this theory is often observational, and fatigue is rarely controlled.

Study/experimental/research design: much more than statistics.

Context: The purpose of study, experimental, or research design in scientific manuscripts has changed significantly over the years. It has evolved from an explanation of the design of the experiment (ie, data gathering or acquisition) to an explanation of the statistical analysis. This practice makes "Methods" sections hard to read and understand.

Reflex inhibition of electrically induced muscle cramps in hypohydrated humans.

Introduction: Anecdotal evidence suggests that ingesting small volumes of pickle juice relieves muscle cramps within 35 s of ingestion. No experimental evidence exists supporting the ingestion of pickle juice as a treatment for skeletal muscle cramps.

Methods: On two different days (1 wk apart), muscle cramps were induced in the flexor hallucis brevis (FHB) of hypohydrated male subjects (approximately 3% body weight loss and plasma osmolality approximately 295 mOsm x kg(-1) H2O) via percutaneous tibial nerve stimulation.

Electrolyte and plasma changes after ingestion of pickle juice, water, and a common carbohydrate-electrolyte solution.

Context: Health care professionals advocate that athletes who are susceptible to exercise-associated muscle cramps (EAMCs) should moderately increase their fluid and electrolyte intake by drinking sport drinks. Some clinicians have also claimed drinking small volumes of pickle juice effectively relieves acute EAMCs, often alleviating them within 35 seconds. Others fear ingesting pickle juice will enhance dehydration-induced hypertonicity, thereby prolonging dehydration.

Electrical stimulation cramp threshold frequency correlates well with the occurrence of skeletal muscle cramps.

The minimum electrical stimulation frequency (HZ) at which a muscle cramps is termed threshold frequency (TF). TF is theorized to represent one's predisposition to cramping; however, TF and cramp occurrence have never been correlated. We hypothesized that TF would be lower in individuals with a cramp history and lower on the second of two days of testing; genetics may partially explain this lower TF.

Reliability and validity of electrothermometers and associated thermocouples.

Objective: Examine thermocouple model uncertainty (reliability+validity).

Design: First, a 3x3 repeated measures design with independent variables electrothermometers and thermocouple model. Second, a 1x3 repeated measures design with independent variable subprobe.

Are room temperature and thermal neutral synonymous terms? An investigation of common therapeutic modality control variables.

Context: Therapeutic modality control variables are thought to be thermal neutral, a term sometimes used interchangeably with room temperature. We question this common assumption.

Objective: To determine thermal neutrality of common therapeutic modality control variables.

Pain and soreness associated with a percutaneous electrical stimulation muscle cramping protocol.

Muscle cramps are difficult to study scientifically because of their spontaneity and unpredictability. Various laboratory techniques to induce muscle cramps have been explored but the best technique for inducing cramps is unclear. Electrical stimulation appears to be the most reliable, but there is a perception that it is extremely painful.

An 18-day stretching regimen, with or without pulsed, shortwave diathermy, and ankle dorsiflexion after 3 weeks.

Context: The amount of retained ankle flexibility gains and the effects of diathermy on those gains are unclear.

Objective: To determine the retention of flexibility 3 weeks after an 18-day stretching regime and the effect of pulsed, shortwave diathermy on that retention.

Design: We used a 2x4 factorial with repeated measures on day (1, 19, 24, and 39).

Neoprene thigh sleeves and muscle cooling after exercise.

Context: Neoprene sleeves are alleged to increase heat in skeletal muscle, but no published research supports this belief.

Objectives: To quantify anterior thigh skin and intramuscular temperature changes in varsity athletes wearing a neoprene thigh sleeve.

Design: A 2 x 2 x 3 x 5 factorial design with replicated measures on 3 variables.

The uncertainty (validity and reliability) of three electrothermometers in therapeutic modality research.

Context: Data from electrothermometers are used to determine therapeutic modality usage, but the value of experimental results is only as good as the data collected.

Objective: To determine the reliability and validity of 3 electrothermometers from 2 manufacturers.

Design: A 3 x 4 x 17 factorial with repeated measures on 2 factors.

Human Tissue-Temperature Rise During Ultrasound Treatments With the Aquaflex Gel Pad.

OBJECTIVE: To measure tissue-temperature rise in the lateral aspect of the ankle during 10-minute ultrasound treatments with ultrasound gel (gel), a gel pad with a thin layer of ultrasound gel on the top (gel/pad), and a gel pad with a thin layer of ultrasound gel on the top and the bottom coated with ultrasound gel (gel/pad/gel). DESIGN AND SETTING: We used a 1 x 3 repeated-measures, crossover design. The dependent variables were tissue-temperature change and time to peak temperature.

Pulsed Shortwave Diathermy and Prolonged Long-Duration Stretching Increase Dorsiflexion Range of Motion More Than Identical Stretching Without Diathermy.

OBJECTIVE: To compare the effects of 3 treatments on ankle dorsiflexion range of motion: prolonged long-duration stretching, pulsed shortwave diathermy followed by stretching, and pulsed shortwave diathermy, stretching, and ice combined. DESIGN AND SETTING: A 2 x 5 x 15 repeated-measures (on 2 factors) design guided this study. Range-of-motion change in triceps surae flexibility was the dependent variable.

The Carry-Over Effects of Diathermy and Stretching in Developing Hamstring Flexibility.

OBJECTIVE: To compare the effects of low-load, short-duration stretching with or without high-intensity, pulsed short-wave diathermy on hamstring flexibility. DESIGN AND SETTING: We used a single-blind, repeated-measures design (pretest and posttest for all treatments) that included a placebo. The 3 independent variables were treatment mode, pretest and posttest measurements, and day.

Effects of warm-up before eccentric exercise on indirect markers of muscle damage.

Purpose: To test whether active and passive warm-up conducted before eccentric exercise attenuates clinical markers of muscle damage.

Methods: Untrained subjects were exposed to one of five conditions: low-heat passive warm-up (N = 10), high-heat passive warm-up (N = 4), or active warm-up (N = 9), preceding eccentric exercise; eccentric exercise without warm-up (N = 10); or high-heat passive warm-up without eccentric exercise (N = 10). Passive warm-up of the elbow flexors was achieved using pulsed short-wave diathermy, and active warm-up was achieved by concentric contraction.