Amelioration of Anxiety Associated with Opioid Withdrawal by Activation of Spinal Mechanoreceptors Via Novel Heterodyned Whole Body Vibration.

Objectives: Opioid use disorder (OUD)-associated overdose deaths have reached epidemic proportions worldwide. An important driving force for relapse is anxiety associated with opioid withdrawal. We hypothesized that our new technology, termed heterodyned whole-body vibration (HWBV) would ameliorate anxiety associated with OUD. Methods: Using a randomized, placebo (sham)-controlled, double-blind study design in an NIH-sponsored Phase 1 trial, we evaluated 60 male and 26 female participants diagnosed with OUD and undergoing treatment at pain and rehabilitation clinics. We utilized the Hamilton Anxiety Scale (HAM-A) and a daily visual analog scale anxiety rating (1-10) to evaluate anxiety. Subjects were treated for 10 min 5X/week for 4 weeks with either sham vibration (no interferential beat or harmonics) or HWBV (beats and harmonics). The participants also completed a neuropsychological test battery at intake and discharge. Results: In OUD subjects with moderate anxiety, there was a significant improvement in daily anxiety scores in the HWBV group compared to the sham treatment group (p=3.41 × 10-7). HAM-A scores in OUD participants at intake showed moderate levels of anxiety in OUD participants (HWBV group: 15.9 ± 1.6; Sham group: 17.8 ± 1.6) and progressively improved in both groups at discharge, but improvement was greater in the HWBV group (p=1.37 × 10-3). Furthermore, three indices of neuropsychological testing (mental rotations, spatial planning, and response inhibition) were significantly improved by HWBV treatment. Conclusions: These findings support HWBV as a novel, non-invasive, non-pharmacological treatment for anxiety associated with OUD.

Positional release therapy and therapeutic massage reduce muscle trigger and tender points.

OBJECTIVE: To determine if positional release therapy (PRT) or therapeutic massage (TM) was more effective in the treatment of trigger and tender points in the upper trapezius muscle. BACKGROUND: Trigger points in the upper trapezius muscle are common and can be painful. Trigger points are commonly treated using TM however, PRT is a novel treatment that deserves further investigation. METHODS: Sixty healthy male (24) and female (36) participants, (age = 27.1 ± 8.8 years, wt = 75.2 ± 17.9 kg, ht = 172.8 ± 9.7 cm) presenting with upper trapezius pain and a trigger point were recruited and randomized into either the TM or PRT group. Upper trapezius trigger points were found via palpation. Pain level was evaluated using a visual analog scale (VAS) and pain pressure threshold (PPT) was assessed using a pressure algometer. Muscle thickness was measured by B-mode ultrasound, while muscle stiffness was measured by shear-wave elastography (SWE). Participants were measured at baseline, posttreatment and again 48 h later. RESULTS: Both treatments were effective in treatment of pain and muscle stiffness. Although no statistical group differences existed, treatment using PRT showed decreased pain averages and decreased pressure sensitivity at both post treatment, and 48 h later. Neither treatment was able to maintain the reduced muscle stiffness at the 48-h measure in males. CONCLUSION: Both treatments showed a significant ability to reduce pain and acutely decrease muscle stiffness. Although not statistically different, clinically PRT is more effective at decreasing pain, and decreasing pressure sensitivity. Neither treatment method produced a long lasting effect on muscle stiffness in males.

Acute effect of whole-body vibration on electromechanical delay and vertical jump performance.

OBJECTIVES: To determine if a change in vertical jump performance from acute whole-body vibration can be explained by indirectly assessing spindle sensitivity from electromechanical delay. METHODS: Using a counter-balanced design, twenty college-aged participants performed whole-body vibration (WBV) and control treatments. WBV included 10 intervals (26 Hz, 3.6 mm) of 60 s in a half-squat followed by 60 s of rest. After 5 intervals, participants rested for 6-minutes before commencing the final 5 intervals. For the control, the exact same protocol of whole-body vibration was performed but without vibration. Electromechanical delay and vertical jump were assessed at baseline, during the 6-minute rest period and immediately after whole-body vibration and control. RESULTS: There were no differences between treatments, for both electromechanical delay (F(2, 38)=1.385, p=0.263) and vertical jump (F(2, 38)=0.040, p<0.96). Whole-body vibration had no effect on vertical jump performance. CONCLUSION: The current whole-body vibration protocol is not effective for acute vertical jump or electromechanical delay enhancement. Also, since there was no effect on electromechanical delay, this suggests that whole-body vibration did not enhance muscle spindle sensitivity for the parameters examined.

Effect of Resonant Frequency Vibration on Delayed Onset Muscle Soreness and Resulting Stiffness as Measured by Shear-Wave Elastography.

This study utilized resonant frequency vibration to the upper body to determine changes in pain, stiffness and isometric strength of the biceps brachii after eccentric damage. Thirty-one participants without recent resistance training were randomized into three groups: a Control (C) group and two eccentric exercise groups (No vibration (NV) and Vibration (V)). After muscle damage, participants in the V group received upper body vibration (UBV) therapy for 5 min on days 1-4. All participants completed a visual analog scale (VAS), maximum voluntary isometric contraction (MVIC), and shear wave elastography (SWE) of the bicep at baseline (pre-exercise), 24 h, 48 h, and 1-week post exercise. There was a significant difference between V and NV at 24 h for VAS (p = 0.0051), at 24 h and 1-week for MVIC (p = 0.0017 and p = 0.0016, respectively). There was a significant decrease in SWE for the V group from 24-48 h (p = 0.0003), while there was no significant change in the NV group (p = 0.9341). The use of UBV resonant vibration decreased MVIC decrement and reduced VAS pain ratings at 24 h post eccentric damage. SWE was strongly negatively correlated with MVIC and may function as a predictor of intrinsic muscle state in the time course of recovery of the biceps brachii.

The Effect of Beat Frequency Vibration on Sleep Latency and Neural Complexity: A Pilot Study.

Insomnia affects millions of people worldwide, and non-pharmacological treatment options are limited. A bed excited with multiple vibration sources was used to explore beat frequency vibration (BFV) as a non-pharmacological treatment for insomnia. A repeated measures design pilot study of 14 participants with mild-moderate insomnia symptom severity (self-reported on the Insomnia Severity Index) was conducted to determine the effects of BFV, and traditional standing wave vibration (SWV) on sleep latency and sleep electrocortical activity. Participants were monitored using high-density electroencephalography (HD-EEG). Sleep latency was compared between treatment conditions. A trend of decreasing sleep latency due to BFV was found for unequivocal sleep latency (p ≤ 0.068). Neural complexity during wake, N1, and N2 stages were compared using Multi-Scale Sample Entropy (MSE), which demonstrated significantly lower MSE between wake and N2 stages (p ≤ 0.002). During N2 sleep, BFV showed lower MSE than the control session in the left frontoparietal region. As a measure of information integration, reduced entropy may indicate that BFV decreases conscious awareness during deeper stages of sleep. SWV caused reduced alpha activity and increased delta activity during wake. BFV caused increased delta activity during N2 sleep. These preliminary results suggest that BFV may help decrease sleep latency, reduce conscious awareness, and increase sleep drive expression during deeper stages of sleep. SWV may be beneficial for decreasing expression of arousal and increasing expression of sleep drive during wake, implying that beat frequency vibration may be beneficial to sleep.

Added body mass alters plantar shear stresses, postural control, and gait kinetics: Implications for obesity.

CONTEXT: Obesity is a growing global health concern. The increased body mass and altered mass distribution associated with obesity may be related to increases in plantar shear that putatively leads to physical functional deficits. Therefore, measurement of plantar shear may provide unique insights on the effects of body mass and body distribution on physical function or performance. PURPOSE: 1) To investigate the effects of body mass and distribution on plantar shear. 2) To examine how altered plantar shear influences postural control and gait kinetics. HYPOTHESIS: 1) a weighted vest forward distributed (FV) would shift the center of pressure (CoP) location forward during standing compared with a weighted vest evenly distributed (EV), 2) FV would increase plantar shear spreading forces more than EV during standing, 3) FV would increase postural sway during standing while EV would not, and 4) FV would elicit greater compensatory changes during walking than EV. METHODS: Twenty healthy young males participated in four different tests: 1) static test (for measuring plantar shear and CoP location without acceleration, 2) bilateral-foot standing postural control test, 3) single-foot standing postural test, and 4) walking test. All tests were executed in three different weight conditions: 1) unweighted (NV), 2) EV with 20% added body mass, and 3) FV, also with 20% added body mass. Plantar shear stresses were measured using a pressure/shear device, and several shear and postural control metrics were extracted. Repeated measures ANOVAs with Holms post hoc test were used to compare each metric among the three conditions (α = 0.05). RESULTS: FV and EV increased both AP and ML plantar shear forces compared to NV. FV shifted CoP forward in single-foot trials. FV and EV showed decreased CoP range and velocity and increased Time-to-Boundary (TTB) during postural control compared to NV. EV and FV showed increased breaking impulse and propulsive impulse compared to NV. In addition, EV showed even greater impulses than FV. While EV increased ML plantar shear spreading force, FV increased AP plantar shear spreading force during walking. CONCLUSION: Added body mass increases plantar shear spreading forces. Body mass distribution had greater effects during dynamic tasks. In addition, healthy young individuals seem to quickly adapt to external stimuli to control postural stability. However, as this is a first step study, follow-up studies are necessary to further support the clinical role of plantar shear in other populations such as elderly and individuals with obesity or diabetes.

Preseason Screen Cannot Predict Injury over Three Years of College Football.

PURPOSE: This study aimed to investigate if the Functional Movement Screen (FMS) total score, individual component test scores, or number of asymmetries can predict noncontact injury risk over three consecutive seasons of National Collegiate Athletic Association Division I football. METHODS: Because football teams comprise individuals with vastly different physical characteristics and playing responsibilities, we divided the subjects into three homogeneous groups based on position (big, combo, and skill). Each FMS score was assessed with regard to the total team score and by individual position groups. For our injury analysis, we also controlled for exposure. Two hundred and eight National Collegiate Athletic Association Division I athletes participated over three consecutive seasons, yielding a total of 343 observations. RESULTS: There was no significant relationship between total FMS score and likelihood of injury when analyzed by the total team or by position group. These findings were the same for all groups, for both the total number of injuries and injuries weighted by injury exposure. The only significant findings occurred when we considered individual test item scores to injury by position group. We only found a significant relationship in the expected direction with push-up stability in the combo group. CONCLUSIONS: FMS was not a good predictor of noncontact injury.

Whole-Body Vibration as a Warm-up Before Exercise-Induced Muscle Damage on Symptoms of Delayed-Onset Muscle Soreness in Trained Subjects.

Magoffin, RD, Parcell, AC, Hyldahl, RD, Fellingham, GW, Hopkins, JT, and Feland, JB. Whole-body vibration as a warm-up before exercise-induced muscle damage on symptoms of delayed-onset muscle soreness in trained subjects. J Strength Cond Res 34(4): 1123-1132, 2020-There is no clear scientific evidence that whole-body vibration (WBV) used as a warm-up before performing eccentric exercise mitigates delayed-onset muscle soreness (DOMS) and speeds strength loss recovery. These benefits were observed primarily in nonresistance-trained individuals. The aim of this study was to determine whether WBV could mitigate soreness and expedite strength recovery for resistance-trained individuals when used as a warm-up before eccentric exercise. Thirty resistance-trained males completed 300 maximal eccentric contractions of the quadriceps after warming up with (WBV) or without (CON) WBV. Both CON and WBV experienced significant isometric (26.3 and 30.2%, respectively) and dynamic (50.9 and 46.4%, respectively) strength loss immediately after exercise. Isometric strength was significantly depressed after 24 hours in the CON group (8.2% p < 0.02), but not in the WBV group (5.9% p = 0.7). Isometric strength was no longer significantly depressed after 48 hours in the CON group (6.1% p < 0.07) or the WBV group (4.1% p = 0.20). Dynamic strength was significantly decreased in both the CON and WBV groups at 24 hours (17.7% p < 0.001 and 15.5% p < 0.001, respectively) and 48 hours (17.1% p < 0.01 and 13.6% p < 0.002), but only significant for the CON at 1 week after exercise (8.6% p = 0.05). Pain as measured by a visual analog scale was significant in both groups at 24 and 48 hours after exercise, but WBV experienced significantly less soreness than the CON group after 24 hours (28 vs. 46 mm p < 0.01, respectively) and 48 hours (38 vs. 50 mm p < 0.01). Pain pressure threshold increased significantly in both groups, but there was no difference between groups. These results suggest the use of WBV before eccentric exercise mildly mitigates DOMS in trained individuals. Application of WBV can function as a quick mode of warm-up before resistance training and can decrease pain perception from DOMS. This may be beneficial to athletes undergoing a heavy strength training phase where DOMS is likely.

Effect of Cuff Pressure on Blood Flow during Blood Flow-restricted Rest and Exercise.

PURPOSE: This study investigated the relationship between blood flow restriction (BFR) cuff pressure and blood flow at rest and during exercise, with the aim of determining if lower cuff pressures will provide an ischemic stimulus comparable to higher pressures. METHODS: The relationship between blood flow and cuff pressure at rest was determined by measuring blood flow (Doppler Ultrasound) through the superficial femoral artery (SFA) in 23 adults across a range of pressures (0%-100% Arterial Occlusion Pressure at rest [rAOP]). The interplay between cuff pressure, blood flow and exercise was assessed by determining AOP at rest and during plantar flexion exercise (eAOP) and subsequently measuring the blood flow response to plantar flexion exercise with BFR cuff pressure set to either 40% rAOP or 40% eAOP. RESULTS: At rest, a nonlinear relationship between cuff pressure and blood flow through the SFA exhibited a plateau at moderate pressures, with nonsignificant differences in blood flow (~9%, P = 1.0) appearing between pressures ranging from 40% to 80% rAOP. While eAOP was greater than rAOP (229 ± 1.5 mm Hg vs 202 ± 1.5 mm Hg, P < 0.01), blood flow during plantar flexion exercise did not significantly differ (P = 0.49) when applying 40% rAOP or 40% eAOP. CONCLUSIONS: Blood flow through the SFA exhibits a nonlinear relationship with cuff pressure, such that cuff pressures in the range of 40% to 80% rAOP reduce blood flow to approximately the same degree. The BFR interventions opting for lower (e.g., 40% AOP), more comfortable pressures will likely provide an ischemic stimulus comparable to that of higher (80% AOP), less-comfortable pressures.

Effects of Whole-Body Vibration on Flexibility and Stiffness: A Literature Review.

The effects of whole-body vibration (WBV) on flexibility and muscle stiffness are focused areas of research. Many studies have been performed over a large range of vibratory conditions and have reported varied results on effectiveness. When reviewing the published literature, it is difficult to track the vibration parameters that have positive effects and which have negative or no effects. In writing this paper, over 80 articles were evaluated, 24 of which met the inclusion requirements. The data gathered in the articles were used to develop charts that illustrate the vibration conditions that elicit helpful, harmful, and no effects on flexibility and muscle stiffness. A combination of published data shows that acceleration is the best metric to predict the effectiveness of WBV for improving flexibility and muscle stiffness. This review shows that acceleration in the range of 5g to 10g was most effective in increasing flexibility. Published data on muscle and tendon stiffness are limited, but shows that although WBV is generally significantly less effective in increasing stiffness than increasing flexibility, accelerations below 6.4g were the most effective.

The acute effects of stretching with vibration on dynamic flexibility in young female gymnasts.

BACKGROUND: While stretching with vibration has been shown to improve static flexibility; the effect of stretching with vibration on dynamic flexibility is not well known. The purpose of this study was to examine the effectiveness of stretching with vibration on acute dynamic flexibility and jump height in novice and advanced competitive female gymnasts during a split jump. METHODS: Female gymnast (N.=27, age: 11.5±1.7 years, Junior Olympic levels 5-10) participated in this cross-over study. Dynamic flexibility during gymnastic split jumps were video recorded and analyzed with Dartfish software. All participants completed both randomized stretching protocols with either the vibration platform turned on (VIB) (frequency of 30 Hz and 2 mm amplitude) or off (NoVIB) separated by 48 h. Participants performed 4 sets of three stretches on the vibration platform. Each stretch was held for 30 seconds with 5 seconds rest for a total of 7 minutes of stretch. RESULTS: Split jump flexibility decreased significantly from pre to post measurement in both VIB (-5.8±5.9°) (P<0.001) and NoVIB (-2.6±6.1°) (P=0.041) conditions (adjusted for gymnast level). This effect was greatest in lower skill level gymnasts (P=0.003), while the highest skill level gymnasts showed no significant decrease in the split jump (P=0.105). Jump height was not significantly different between conditions (P=0.892) or within groups (P=0.880). CONCLUSIONS: An acute session of static stretching with or without vibration immediately before performance does not alter jump height. Stretching with vibration immediately prior to gymnastics competition decreases split jump flexibility in lower level gymnasts more than upper level gymnasts.

Performance on the Functional Movement Screen in older active adults.

BACKGROUND: The Functional Movement Screen (FMS™) has become increasingly popular for identifying functional limitations in basic functional movements. This exploratory and descriptive study was undertaken to confirm feasibility of performing the FMS™ in older active adults, assess prevalence of asymmetries and to evaluate the relationship between functional movement ability, age, physical activity levels and body mass index (BMI). METHODS: This is an observational study; 97 men (n = 53) and women (n = 44) between the ages of 52 and 83 participated. BMI was computed and self-reported physical activity levels were obtained. Subjects were grouped by age (5-year intervals), BMI (normal, over-weight, and obese) and sex. Each participant's performance on the FMS™ was digitally recorded for later analysis. RESULTS: The youngest age group (50-54 years) scored highest in all seven tests and the oldest age group (75+) scored lowest in most of the tests compared to all other age groups. The subjects in the "normal weight" group performed no different than those who were in the "overweight" group; both groups performed better than the "obese" group. Of the 97 participants 54 had at least one asymmetry. The pairwise correlations between the total FMS™ score and age (r = -0.531), BMI (r = -0.270), and the measure of activity level (r = 0.287) were significant (p < 0.01 for all). CONCLUSION: FMS™ scores decline with increased BMI, increased age, and decreased activity level. The screen identifies range of motion- and strength-related asymmetries. The FMS™ can be used to assess functional limitations and asymmetries. Future research should evaluate if a higher total FMS™ score is related to fewer falls or injuries in the older population.

Effect of whole body vibration on skin blood flow and nitric oxide production.

BACKGROUND: Vascular dysfunction due to hyperglycemia in individuals with diabetes is a factor contributing to distal symmetric polyneuropathy (DSPN). Reactive oxygen species reduce the bioavailability of nitric oxide (NO), a powerful vasodilator, resulting in reduced circulation and nerve ischemia. Increases in blood NO concentrations and circulation have been attributed to whole body vibration (WBV). The purpose of this study was to the determine the effects of low-frequency, low-amplitude WBV on whole blood NO concentrations and skin blood flow (SBF) in individuals with symptoms of DSPN. METHODS: Ten patients with diabetes and impaired sensory perception in the lower limbs participated in this crossover study. Each submitted to 2 treatment conditions, WBV and sham, with a 1-week washout period between. Blood draws for NO analysis and laser Doppler imager scans of SBF were performed before, immediately after, and following a 5-minute recovery of each of the treatments. RESULTS: Low-frequency, low-amplitude WBV significantly increased SBF compared to the sham condition (F(2,18) = 5.82, P = .0115). Whole blood NO concentrations did not differ between the WBV and sham conditions immediately or 5 minutes after treatment (F(2,18) = 1.88, P = .1813). CONCLUSIONS: These findings demonstrate that patients with diabetes respond to WBV with increased SBF compared to the sham condition. The implication is that WBV is a potential nonpharmacological therapy for neurovascular complications of diabetes.

Hamstring flexibility increases the same with 3 or 9 repetitions of stretching held for a total time of 90 s.

OBJECTIVE: To determine if stretching for a constant total time with differing repetition durations and number of repetitions over a 6-week period produced different changes in hamstring flexibility measured by knee extension range of motion (ROM). DESIGN: Randomized Control Trial. SETTING: University laboratory. SUBJECTS: 34 volunteers, 18-25 years old with tight hamstrings as determined by a greater than 30° loss of knee extension with hip flexed to 90° participated in the study. MAIN OUTCOME MEASURES: Change in knee extension ROM was assessed in participants who were randomly assigned to a control, or to a stretching group of either 10 s for 9 repetitions or 30 s for 3 repetitions, for a total stretch time of 90 s. Each group stretched 6 days a week for 6 weeks. RESULTS: Pre to post stretch comparison indicated both stretching groups were successful in increasing joint ROM (11.6 ± 5.25°-13.4 ± 5.36°) over the control (F = 19.77, p < 0.003). However, there was no significant difference between the stretching groups (p = 0.9). CONCLUSION: Stretching for 6 weeks for total of 90 s showed increased joint ROM regardless of the number of repetitions or the duration of each individual stretch.

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. DESIGN: Controlled laboratory study. SETTING: Therapeutic modality laboratory. PARTICIPANTS: 30 physically active healthy male subjects who were free from any lower extremity orthopedic, neurological, cardiovascular, or endocrine pathologies. MAIN OUTCOME MEASURES: Perceived pain was measured every minute. Surface temperature was also assessed in the center of the patella and the popliteal fossa. RESULTS: There was a significant interaction between group and time (F68,864 = 3.0, P = .0001). At the first minute, there was no difference in pain between the 3 groups (saline/cryo = 4.80 ± 4.87 mm, saline/sham = 2.80 ± 3.55 mm, no saline/cryo = 4.00 ± 3.33 mm). During the first 5 min, pain increased from 4.80 ± 4.87 to 45.90 ± 21.17 mm in the saline/cryo group and from 2.80 ± 3.55 to 31.10 ± 20.25 mm in the saline/sham group. Pain did not change within the no-saline/cryo group, 4.00 ± 3.33 to 1.70 ± 1.70 mm. Pain for the saline/sham group remained constant for 17 min. Cryo decreased pain for 16 min in the saline/cryo group. There was no difference in preapplication surface temperature between or within each group. No change in temperature occurred within the saline/sham. Cooling and rewarming were similar in both cryo groups. Ambient temperature fluctuated less than 1°C during data collection. CONCLUSION: Intermittent infusion of sterile 5% hypertonic saline may be a useful experimental pain model in establishing a constant level of pain in a controlled laboratory setting. Cryotherapy decreased the induced anterior knee pain for 16 min.

Static stretching does not alter pre and post-landing muscle activation.

BACKGROUND: Static stretching may result in various strength and power deficiencies. Prior research has not determined, however, if static stretching causes a change in muscle activation during a functional task requiring dynamic stability. The purpose of this study was to determine if static stretching has an effect on mean pre and postlanding muscle (vastus medialis VM, vastus lateralis VL, medial hamstring MH, and biceps femoris BF) activity. METHODS: 26 healthy, physically active subjects were recruited, from which 13 completed a 14-day static stretching regimen for the quadriceps and hamstrings. Using the data from the force plate and EMG readings, a mean of EMG amplitude was calculated for 150 msec before and after landing. Each trial was normalized to an isometric reference position. Means were calculated for the VM, VL, MH, and BF from 5 trials in each session. Measures were collected pre, immediately following the 1st stretching session, and following 2 weeks of stretching. RESULTS: A 14-day static stretching regimen resulted in no significant differences in pre or postlanding mean EMG amplitude during a drop landing either acutely or over a 14-day period. CONCLUSIONS: Static stretching, done acutely or over a 14-day period does not result in measurable differences of mean EMG amplitude during a drop landing. Static stretching may not impede dynamic stability of joints about which stretched muscles cross.

Reliability of 16 balance tests in individuals with Down syndrome.

To assess test-retest reliability scores on 16 balance tests of 21 individuals with Down syndrome whose ages ranged from 5 to 31 yr., participants performed a standing test on firm and soft surfaces with the eyes open and closed, the balance subset of the Bruininks-Oseretsky test, full turn, timed-up-and-go test, forward reach, and sit-to-stand. Each participant completed all 16 tests twice in one day and then again on a subsequent day for a total of 4 sessions. The interclass reliability correlation coefficients (ICC) value for each measure of balance varied considerably by age and sex. Based on having an ICC > .50, only 3 tests were reliable in young males and young females, whereas 5 tests could reliably be used in adult females and 9 tests could reliably be used in adult males. The results of this study raise suspicions as to the reliability of tests commonly used to assess balance and differences in reliability due to age and sex. Results of balance tests should be interpreted with caution in males and females with Down syndrome across the age span.

Whole-body vibration strengthening compared to traditional strengthening during physical therapy in individuals with total knee arthroplasty.

This study investigated the use of whole-body vibration (WBV) as an alternative strengthening regimen in the rehabilitation of individuals with total knee arthroplasty (TKA) compared with traditional progressive resistance exercise (TPRE). Individuals post TKA (WBV n = 8; TPRE n = 8) received physical therapy with WBV or with TPRE for 4 weeks. Primary dependent variables were knee extensor strength, quadriceps muscle activation, mobility, pain, and range of motion (ROM). There was a significant increase in knee extensor strength and improvements in mobility, as measured by maximal volitional isometric contraction and the Timed Up and Go Test (TUG), respectively, for both groups (p < 0.01). The WBV knee extensor strength improved 84.3% while TPRE increased 77.3%. TUG scores improved 31% in the WBV group and 32% for the TPRE group. There were no significant differences between groups for strength or muscle activation (Hotelling's T(2) = 0.42, p = 0.80) or for mobility (F = 0.54; p = 0.66). No adverse side effects were reported in either group. In individuals with TKA, both WBV and TPRE showed improved strength and function. Influence of WBV on muscle activation remains unclear, as muscle activation levels were near normal for both groups.

Ground reaction force differences between running shoes, racing flats, and distance spikes in runners.

Various shoes are worn by distance runners throughout a training season. This study measured the differences in ground reaction forces between running shoes, racing flats, and distance spikes in order to provide information about the potential effects of footwear on injury risk in highly competitive runners. Ten male and ten female intercollegiate distance runners ran across a force plate at 6.7 m·s(-1) (for males) and 5.7 m·s(-1) (for females) in each of the three types of shoes. To control for differences in foot strike, only subjects who exhibited a heel strike were included in the data analysis. Two repeated-measures ANOVAs with Tukey's post-hoc tests (p < 0.05) were used to detect differences in shoe types among males and females. For the males, loading rate, peak vertical impact force and peak braking forces were significantly greater in flats and spikes compared to running shoes. Vertical stiffness in spikes was also significantly greater than in running shoes. Females had significantly shorter stance times and greater maximum propulsion forces in racing flats compared to running shoes. Changing footwear between the shoes used in this study alters the loads placed on the body. Care should be taken as athletes enter different phases of training where different footwear is required. Injury risk may be increased since the body may not be accustomed to the differences in force, stance time, and vertical stiffness. Key pointsTo determine the differences in ground reaction forces between regular running shoes and competitive footwear, force plate data was obtained from 10 males (6.7 m·s(-1)) and 10 females (5.7 m·s(-1)) for each of three shoe types.Data from men and women were analyzed in two separate groups, and significant differences were found for various GRF components between the three types of shoes.The significant increases in GRF components in competitive footwear suggest that the body must deal with greater impact forces in these shoes than in running shoes at the same running speed.The results from this study warrant the recommendation that runners transition gradually from periods when most or all of their training is done in running shoes to more competitive seasons when more of their training is done in racing flats and spikes.