Context: Limited dorsiflexion (DF) range of motion (ROM) is commonly observed in both the athletic and general populations and is a predisposing factor for lower extremity injury. Graston Technique® (GT) is a form of instrument-assisted soft tissue mobilization (IASTM), used commonly to increase ROM. Evidence of the long-term effects of GT on ROM is lacking, particularly comparing the full GT protocol versus IASTM alone. Objective: To evaluate the effectiveness of 6 sessions of the GT or IASTM compared with a control (CON) group for increasing closed-chain DF ROM. Design: Cohort design with randomization. Setting: Athletic training clinic. Patients or OtherParticipants: A total of 23 physically active participants (37 limbs) with <34° of DF. Participants’ limbs were randomly allocated to the GT, IASTM, or CON group. Intervention: Participants’ closed-chain DF ROM (standing and kneeling) were assessed at baseline and 24–48 hours following their sixth treatment. Participants in the CON group were measured at baseline and 3 weeks later. The intervention groups received 6 treatments during a 3-week period, whereas the CON group received no treatment. The GT group received a warm-up, instrument application, stretching, and strengthening of the triceps surae. The IASTM group received a warm-up and instrument application. Main Outcome Measures: Closed-chain DF was assessed with a digital inclinometer in standing and kneeling. Results: A significant difference between groups was found in the standing position (P = .03) but not in kneeling (P = .15). Post hoc testing showed significant improvements in DF in standing following the GT compared with the control (P = .02). Conclusions: The GT significantly increases ankle DF following 6 treatments in participants with DF ROM deficits; however, no differences were found between GT and IASTM. The GT may be an effective intervention for clinicians to consider when treating patients with DF deficits.
Holly M. Bush, Justin M. Stanek, Joshua D. Wooldridge, Stephanie L. Stephens and Jessica S. Barrack
Jessica M. Stephens, Shona Halson, Joanna Miller, Gary J. Slater and Christopher D. Askew
The use of cold-water immersion (CWI) for postexercise recovery has become increasingly prevalent in recent years, but there is a dearth of strong scientific evidence to support the optimization of protocols for performance benefits. While the increase in practice and popularity of CWI has led to multiple studies and reviews in the area of water immersion, the research has predominantly focused on performance outcomes associated with postexercise CWI. Studies to date have generally shown positive results with enhanced recovery of performance. However, there are a small number of studies that have shown CWI to have either no effect or a detrimental effect on the recovery of performance. The rationale for such contradictory responses has received little attention but may be related to nuances associated with individuals that may need to be accounted for in optimizing prescription of protocols. To recommend optimal protocols to enhance athletic recovery, research must provide a greater understanding of the physiology underpinning performance change and the factors that may contribute to the varied responses currently observed. This review focuses specifically on why some of the current literature may show variability and disparity in the effectiveness of CWI for recovery of athletic performance by examining the body temperature and cardiovascular responses underpinning CWI and how they are related to performance benefits. This review also examines how individual characteristics (such as physique traits), differences in water-immersion protocol (depth, duration, temperature), and exercise type (endurance vs maximal) interact with these mechanisms.
Nicholas M. Edwards, Heidi J. Kalkwarf, Jessica G. Woo, Philip R. Khoury, Stephen R. Daniels and Elaine M. Urbina
The objective of this study was to characterize the relationship between objectively-measured physical activity (PA) and cardiovascular risk factors in 7-year-old children and test the hypothesis that it differs by race.
Cross-sectional study of 308 7-year-old children drawn from a major US metropolitan community. PA (moderate-to-vigorous, MVPA; light, LPA; and inactivity, IA) was measured by accelerometry (RT3). Cardiovascular risk factors included BMI, blood pressure, and serum lipids, glucose and insulin concentrations. General linear modeling was used to evaluate the independent associations between PA measures and cardiovascular risk factors and interactions by race.
In black children, greater time spent in PA was independently associated with lower levels of triglycerides (MVPA and LPA, both p < .01), glucose (MVPA, p < .05), and insulin (MVPA, p < .01); these associations were not evident in white children. Across races, greater inactivity was independently associated with greater low-density lipoprotein cholesterol in overweight participants (p < .01) but not in normal weight participants. No PA measure was associated with BMI, systolic blood pressure, or high-density lipoprotein cholesterol.
In this cohort of 7-year-old children, the relationship between PA and some cardiovascular risk factors differed by race. These findings may have implications for targeting of PA promotion efforts in children.
Jessica G. Hunter, Alexander M.B. Smith, Lena M. Sciarratta, Stephen Suydam, Jae Kun Shim and Ross H. Miller
Studies of running mechanics often use a standardized lab shoe, ostensibly to reduce variance between subjects; however, this may induce unnatural running mechanics. The purpose of this study was to compare the step rate, vertical average loading rate, and ground contact time when running in standardized lab shoes versus participants’ normal running shoes. Ground reaction forces were measured while the participants ran overground in both shoe conditions at a self-selected speed. The Student’s t-test revealed that the vertical average loading rate magnitude was smaller in lab shoes versus normal shoes (42.09 [11.08] vs 47.35 [10.81] body weight/s, P = .013), while the step rate (170.92 [9.43] vs 168.98 [9.63] steps/min, P = .053) and ground contact time were similar (253  vs 251  ms, P = .5227) and the variance of all outcomes was similar in lab shoes versus normal shoes. Our results indicate that using standardized lab shoes during testing may underestimate the loads runners actually experience during their typical mileage.
Nicholas M. Edwards, Philip R. Khoury, Heidi J. Kalkwarf, Jessica G. Woo, Randal P. Claytor and Stephen R. Daniels
Establishing and maintaining healthy physical activity (PA) levels is important throughout life. The purpose of this study was to determine the extent of PA tracking between ages 3 and 7 y. Objective measures of PA (RT3, triaxial accelerometer) were collected every 4 mo from ages 3–7; data from 234 children with PA measures available during each year of age were analyzed. Mean PA (total, moderate/vigorous (MV), and inactivity [IA]) was calculated for each year of age and adjusted for wear time. Correlations with age 3 PA were moderate at age 4 (r = .42−.45) but declined by age 7 (r = .19−.25). After classification into sex-specific tertiles of PA at age 3, boys in the high age 3 MVPA tertile maintained significantly higher PA at all subsequent ages, while girls in the high age 3 MVPA tertile were not significantly higher at age 6 and 7. Boys and girls in the high age 3 IA tertile had significantly higher IA at multiple subsequent years of age (p < .05 at ages 5 and 6). In conclusion, boys who were relatively more active at age 3 remained more active for several subsequent years. These findings highlight early-childhood differences in physical activity patterns between boys and girls.
Jessica M. Stephens, Shona L. Halson, Joanna Miller, Gary J. Slater, Dale W. Chapman and Christopher D. Askew
Purpose: To explore the influence of body composition on thermal responses to cold-water immersion (CWI) and the recovery of exercise performance. Methods: Male subjects were stratified into 2 groups: low fat (LF; n = 10) or high fat (HF; n = 10). Subjects completed a high-intensity interval test (HIIT) on a cycle ergometer followed by a 15-min recovery intervention (control [CON] or CWI). Core temperature (Tc), skin temperature, and heart rate were recorded continuously. Performance was assessed at baseline, immediately post-HIIT, and 40 min postrecovery using a 4-min cycling time trial (TT), countermovement jump (CMJ), and isometric midthigh pull (IMTP). Perceptual measures (thermal sensation [TS], total quality of recovery [TQR], soreness, and fatigue) were also assessed. Results: Tc and TS were significantly lower in LF than in HF from 10 min (Tc, LF 36.5°C ± 0.5°C, HF 37.2°C ± 0.6°C; TS, LF 2.3 ± 0.5 arbitrary units [a.u.], HF 3.0 ± 0.7 a.u.) to 40 min (Tc, LF 36.1°C ± 0.6°C, HF 36.8°C ±0.7°C; TS, LF 2.3 ± 0.6 a.u., HF 3.2 ± 0.7 a.u.) after CWI (P < .05). Recovery of TT performance was significantly enhanced after CWI in HF (10.3 ± 6.1%) compared with LF (3.1 ± 5.6%, P = .01); however, no differences were observed between HF (6.9% ±5.7%) and LF (5.4% ± 5.2%) with CON. No significant differences were observed between groups for CMJ, IMTP, TQR, soreness, or fatigue in either condition. Conclusion: Body composition influences the magnitude of Tc change during and after CWI. In addition, CWI enhanced performance recovery in the HF group only. Therefore, body composition should be considered when planning CWI protocols to avoid overcooling and maximize performance recovery.
Nicholas M. Edwards, Gregory D. Myer, Heidi J. Kalkwarf, Jessica G. Woo, Philip R. Khoury, Timothy E. Hewett and Stephen R. Daniels
Evaluate effects of local weather conditions on physical activity in early childhood.
Longitudinal prospective cohort study of 372 children, 3 years old at enrollment, drawn from a major US metropolitan community. Accelerometer-measured (RT3) physical activity was collected every 4 months over 5 years and matched with daily weather measures: day length, heating/cooling degrees (degrees mean temperature < 65°F or ≥ 65°F, respectively), wind, and precipitation. Mixed regression analyses, adjusted for repeated measures, were used to test the relationship between weather and physical activity.
Precipitation and wind speed were negatively associated with total physical activity and moderate-vigorous physical activity (P < .0001). Heating and cooling degrees were negatively associated with total physical activity and moderate-vigorous physical activity and positively associated with inactivity (all P < .0001), independent of age, sex, race, BMI, day length, wind, and precipitation. For every 10 additional heating degrees there was a 5-minute daily reduction in moderatevigorous physical activity. For every additional 10 cooling degrees there was a 17-minute reduction in moderate-to-vigorous physical activity.
Inclement weather (higher/lower temperature, greater wind speed, more rain/snow) is associated with less physical activity in young children. These deleterious effects should be considered when planning physical activity research, interventions, and policies.
Jessica M. Stephens, Ken Sharpe, Christopher Gore, Joanna Miller, Gary J. Slater, Nathan Versey, Jeremiah Peiffer, Rob Duffield, Geoffrey M. Minett, David Crampton, Alan Dunne, Christopher D. Askew and Shona L. Halson
Purpose: To examine the effect of postexercise cold-water immersion (CWI) protocols, compared with control (CON), on the magnitude and time course of core temperature (T c) responses. Methods: Pooled-data analyses were used to examine the T c responses of 157 subjects from previous postexercise CWI trials in the authors’ laboratories. CWI protocols varied with different combinations of temperature, duration, immersion depth, and mode (continuous vs intermittent). T c was examined as a double difference (ΔΔT c), calculated as the change in T c in CWI condition minus the corresponding change in CON. The effect of CWI on ΔΔT c was assessed using separate linear mixed models across 2 time components (component 1, immersion; component 2, postintervention). Results: Intermittent CWI resulted in a mean decrease in ΔΔT c that was 0.25°C (0.10°C) (estimate [SE]) greater than continuous CWI during the immersion component (P = .02). There was a significant effect of CWI temperature during the immersion component (P = .05), where reductions in water temperature of 1°C resulted in decreases in ΔΔT c of 0.03°C (0.01°C). Similarly, the effect of CWI duration was significant during the immersion component (P = .01), where every 1 min of immersion resulted in a decrease in ΔΔT c of 0.02°C (0.01°C). The peak difference in T c between the CWI and CON interventions during the postimmersion component occurred at 60 min postintervention. Conclusions: Variations in CWI mode, duration, and temperature may have a significant effect on the extent of change in T c. Careful consideration should be given to determine the optimal amount of core cooling before deciding which combination of protocol factors to prescribe.