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J. William Myrer, J. Brent Feland and Gilbert W. Fellingham

Chronic knee pain is a prevalent health problem of old and middle age. The authors’ objective was to determine whether a topical analgesic would reduce knee pain and improve the function of a group of 40- to 65-year-old people with chronic knee pain. The experimental design was a double-blind, randomized, placebo-controlled clinical trial. The dependent variables were knee pain, active range of motion, and isometric strength. Forty-six men and women volunteered, of whom 3 dropped out, leaving 23 in the treatment group and 20 in the placebo group. Knee pain was assessed with a visual analogue scale and the knee-pain scale for frequency and severity. Testing took place before treatment and after 21 and 35 days of treatment. The results indicated that although both groups experienced improved pain scores, there were no differences between groups over the treatment period for any of the dependent variables.

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Billy E. Cotts, Kenneth L. Knight, J. William Myrer and Shane S. Schulthies

Context:

It has been suggested that contrast-bath therapy alters sensation and enables patients to return to exercise more quickly.

Objective:

To determine whether contrast-bath therapy alters sensation of pressure in the ankle.

Design:

A 2 × 4 × 4 factorial design with repeated measures on 2 factors. Independent variables included gender, time (preapplication and 1, 6, and 11 min postapplication), and treatment (control, cold bath, hot bath, and contrast bath).

Setting:

Laboratory.

Participants:

12 men and 12 women, college track athletes actively engaged in preseason workouts 5-6 days/wk.

Interventions:

Sensation of pressure was tested preapplication and 1, 6, and 11 min postapplication. Each treatment lasted 20 min.

Main Outcome Measure:

Sensation of pressure at baseline and 1, 6, and 11 min postapplication over the anterior talofibular ligament of the right ankle.

Results:

There was no difference between genders. Sensation of pressure was greater for the heat condition than the other 3 conditions at 1 and 6 min postapplication. During the heating condition, sensation of pressure was greater at 1 and 6 min postapplication than during preapplication. During the contrast condition, sensation of pressure was less at 6 min postapplication than during preapplication.

Conclusion:

Contrast- and cold-bath therapy (at 13 °C) do not affect numbness.

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Kazuto Sakita, Matthew K. Seeley, Joseph William Myrer and J. Ty Hopkins

Context:

Standing and side-lying external-rotation exercises produce high activation of the deltoid and infraspinatus. Slight shoulder abduction during these exercises may decrease deltoid activity and increase infraspinatus activity.

Objective:

To determine if the addition of a towel under the arm during standing and side-lying external rotation affects infraspinatus, middle and posterior deltoid, and pectoralis major activation characteristics compared with a no-towel condition.

Design:

Controlled laboratory study.

Participants:

20 male volunteers (age 26 ± 3 y, height 1.80 ± 0.07 m, mass 77 ± 10 kg) who were right-hand dominant and had bilaterally healthy shoulders with no current cervical pathology and no skin infection or shoulder lesion.

Interventions:

External-rotation exercises without a towel roll (0° shoulder abduction) and with a towel roll (30° shoulder abduction) were performed in a standing and side-lying.

Main Outcome Measures:

Maximal voluntary isometric contraction for the infraspinatus, middle and posterior deltoid, and pectoralis major and external rotation in standing and side-lying with and without a towel roll were performed. Normalized average and peak surface EMG amplitude were compared between the towel conditions during standing and side-lying external rotation.

Results:

Both infraspinatus and pectoralis major activity had no significant differences between the towel conditions in standing and side-lying (P > .05). In standing and side-lying, posterior-deltoid activity was significantly greater with a towel roll (P < .05). Middle-deltoid activity had no significant differences between the towel conditions in standing (P > .05). However, in side-lying, middle-deltoid activity was significantly lower with a towel roll (P < .05).

Conclusion:

Middle-deltoid activity decreased with a towel roll during side-lying exercises. More data are needed to determine if a towel roll could be used to potentially reduce superior glide during external-rotation exercises.

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Allen C. Parcell, Jason M. Smith, Shane S. Schulthies, J. William Myrer and Gilbert Fellingham

It is purported that supplementation with Cordyceps Sinensis (CordyMax Cs-4) will improve oxidative capacity and endurance performance. The intent of this investigation was to examine the effects of CordyMax Cs-4 supplementation on VO2peak, ventilatory threshold, and endurance performance in endurance-trained cyclists. Twenty-two male cyclists participated in 5 weeks of supplementation with CordyMax Cs-4 tablets (3 g/d). Training intensity was maintained by weekly documentation and reporting throughout the 5-week period. Subjects completed a VO2peak test and work-based time trial prior to and following the supplementation period. VO2peak was similar within and between placebo (PLA) and treatment (CS) groups prior to (59.9 ± 5.9 vs. 59.1 ± 5.4 ml/kg/min, respectively) and following (60.1 ± 5.5 vs. 57.1 ± 5.8 ml/kg/min, respectively) the supplementation period. Ventilatory threshold (VT) was measured at 72 ± 10% of VO2peak in P and T prior to supplementation and did not change in either group following the supplementation. PLA completed the time trial in 61.4 ± 2.4 min compared to 62.1 ± 4.0 min in T. Time trial measurements did not differ between groups, nor did they change in response to supplementation. It is concluded that 5 weeks of CordyMax Cs-4 supplementation has no effect on aerobic capacity or endurance exercise performance in endurance-trained male cyclists.

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Ulrike H. Mitchell, J. William Myrer, J. Ty Hopkins, Iain Hunter, J. Brent Feland and Sterling C. Hilton

Background and Purpose:

Proprioceptive neuromuscular facilitation (PNF) stretches are widely used in athletics and rehabilitation. Although it has been shown that they produce better range-of-motion (ROM) increases than the slow or static stretch, the mechanisms responsible remain an enigma. This study was conducted to determine whether the previously proposed neurophysiological mechanisms of reciprocal inhibition and autogenic inhibition are responsible for the success of PNF stretches. In addition, the authors assessed the existence of the phenomenon of successive induction because it is used to strengthen reciprocal inhibition.

Methods:

Eighteen subjects 17–44 y performed the PNF stretches contract-relax (CR) and contract-relax, agonist contract (CRAC). EMG data were collected from the medial hamstring muscles via surface and indwelling wire electrodes and analyzed for reciprocal inhibition and successive induction, as well as autogenic inhibition (surface electrodes only).

Results:

Reciprocal inhibition was not evident. The results indicated an elevated rather than an inhibited EMG during the antagonist contraction, possibly representing cocontraction. The authors did confirm the presence of successive induction. Autogenic inhibition was also not evident, and the expected inhibition and therefore lower EMG values after muscle contraction were not observed; instead, they were higher than baseline.

Conclusion:

Previous neurophysiological explanations for mechanisms of PNF stretching appear to be inadequate. This study corroborates previous findings that a muscle’s tone increases during its antagonist’s contraction. Other explanations should be considered regarding the mechanism for the effectiveness of the CRAC and CR PNF techniques in a nonneurologically impaired population.

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Ulrike H. Mitchell, J. William Myrer, J. Ty Hopkins, Iain Hunter, J. Brent Feland and Sterling C. Hilton

Context:

Some researchers have suggested that an alteration of stretch perception could be responsible for the success of the contract-relax (CR) stretch, a stretch technique derived from proprioceptive neuromuscular facilitation (PNF).

Objective:

This study was conducted to determine if the alteration of the stretch perception is a possible explanation for the range of motion (ROM) gains of the CR stretch.

Participants:

Eighteen subjects performed two stretches in randomized order: the slow stretch and the CR stretch.

Main Outcome Measure:

The stretch intensity was controlled. The stretch force was measured and compared between the slow stretch and CR stretch.

Results:

There was a significant difference between the stretch force that could be applied in the PNF stretch (126.0 N) and the slow stretch (108.4 N); P = 0.00086. The average stretch tolerance progressively increased with successive trials from 120.6 N in the first trial to 132.4 N in the fourth trial.

Conclusion:

The alteration of stretch perception plays a role in the success of the CR form of PNF stretching. At least four repetitions of the CR stretch are recommended to get the greatest ROM gain.