Wednesday, November 30, 2011

Do Compression Garments Enhance the Active Recovery Process after High-Intensity Running?


Do Compression Garments Enhance the Active Recovery Process after High-Intensity Running?


by 

Lovell, DI, Mason, DG, Delphinus, EM, and McLellan, CP. Do compression garments enhance the active recovery process after high-intensity running? J Strength Cond Res 25(12): 3264–3268, 2011—

This study examined the effect of wearing waist-to-ankle compression garments (CGs) on active recovery after moderate- and high-intensity submaximal treadmill running. 

Twenty-five male semiprofessional rugby league players performed two 30-minute treadmill runs comprising of six 5-minute stages at 6 km·h−1, 10 km·h−1, approximately 85% V̇O2max, 6 km·h−1 as a recovery stage followed by approximately 85% V̇O2max and 6 km·h−1 wearing either CGs or regular running shorts in a randomized counterbalanced order with each person acting as his own control. All stages were followed by 30 seconds of rest during which a blood sample was collected to determine blood pH and blood lactate concentration [La−]. Expired gases and heart rate (HR) were measured during the submaximal treadmill tests to determine metabolic variables with the average of the last 2 minutes used for data analysis.

 The HR and [La−] were lower (p ≤ 0.05) after the first and second 6 km·h−1 recovery bouts when wearing CGs compared with when wearing running shorts. The respiratory exchange ratio (RER) was higher and [La−] lower (p ≤ 0.05) after the 10 km·h−1 stage, and only RER was higher after both 85% V̇O2max stages when wearing CGs compared with when wearing running shorts.

 There was no difference in blood pH at any exercise stage when wearing the CGs and running shorts. The results of this study indicate that the wearing of CGs may augment the active recovery process in reducing [La−] and HR after high-intensity exercise but not effect blood pH. The ability to reduce [La−] and HR has important consequences for many sports that are intermittent in nature and consist of repeated bouts of high-intensity exercise interspersed with periods of low-intensity exercise or recovery.



Friday, November 18, 2011

Elite golfers' kinematic sequence in full-swing and partial-swing shots


Elite golfers' kinematic sequence in full-swing and partial-swing shots

Sports Biomechanics

Volume 9Issue 4, 2010

Abstract

The aim of this study was to investigate whether kinematic proximal-to-distal sequencing (PDS) and speed-summation are common characteristics of both partial and full-swing shots in golf players of different skill levels and genders. A total of 45 golfers participated, 11 male tournament professionals, 21 male and 13 female elite amateurs. They performed partial shots with a wedge to targets at three submaximal distances, 40, 55 and 70 m, and full-swing shots with a 5 iron and a driver for maximal distance. Pelvis, upper torso and hand movements were recorded in 3D with an electromagnetic tracking system (Polhemus Liberty) at 240 Hz and the magnitude of the resultant angular velocity vector of each segment was computed. 
The results showed a significant proximal-to-distal temporal relationship and a concomitant successive increase in maximum (peak) segment angular speed in every shot condition for both genders and levels of expertise. A proximal-to-distal utilization of interaction torques is indicated. Using a common PDS movement strategy in partial and full-swing golf shots appears beneficial from mechanical and control points of view and could serve the purpose of providing both high speed and accuracy.





 

Wednesday, November 16, 2011

Sport-Related Concussions in United States High Schools


Assessment and Management of Sport-Related Concussions in United States High Schools

Background: Little existing data describe which medical professionals and which medical studies are used to assess sport-related concussions in high school athletes.

Purpose: To describe the medical providers and medical studies used when assessing sport-related concussions. To determine the effects of medical provider type on timing of return to play, frequency of imaging, and frequency of neuropsychological testing.

Study Design: Descriptive epidemiology study.

Methods: All concussions recorded by the High School Reporting Information Online (HS RIO) injury surveillance system during the 2009 to 2010 academic year were included. 2 analyses were conducted for categorical variables. Fisher exact test was used for nonparametric data. Logistic regression analyses were used when adjusting for potential confounders. Statistical significance was considered for P < .05.

Results: The HS RIO recorded 1056 sport-related concussions, representing 14.6% of all injuries. Most (94.4%) concussions were assessed by athletic trainers (ATs), 58.8% by a primary care physician. Few concussions were managed by specialists. The assessment of 21.2% included computed tomography. Computerized neuropsychological testing was used for 41.2%. For 50.1%, a physician decided when to return the athlete to play; for 46.2%, the decision was made by an AT. After adjusting for potential confounders, no associations between timing of return to play and the type of provider (physician vs AT) deciding to return the athlete to play were found.

Conclusion: Concussions account for nearly 15% of all sport-related injuries in high school athletes. The timing of return to play after a sport-related concussion is similar regardless of whether the decision to return the athlete to play is made by a physician or an AT. When a medical doctor is involved, most concussions are assessed by primary care physicians as opposed to subspecialists. Computed tomography is obtained during the assessment of 1 of every 5 concussions occurring in high school athletes.


Am J Sports Med November 2011 vol. 39 no. 11 2304-2310

Tuesday, November 15, 2011

Two Federal Studies Undertaken by the University of South Florida Point to Chiropractic Engagement to Aid in Injury Prevention


Two Federal Studies Undertaken by the University of South Florida Point to Chiropractic Engagement to Aid in Injury Prevention



The Federal government has awarded the University of South Florida (USF), School of Physical Therapy & Rehabilitation Sciences $1.42 million to research the effectiveness of specific exercise interventions for reducing the risk of back injuries amongst some of the nation’s most vulnerable — firefighters and military personnel.
“Back injury is a primary condition that dramatically affects our nation’s heroes — cited as a top reason for disability and early retirement amongst firefighters, and a top non-combat reason for service men and women being displaced from active duty,” says John Mayer, D.C., Ph.D, associate professor and Lincoln College Endowed Chair in Biomechanical and Chiropractic Research at USF, and lead researcher in the $715,000 Department of Defense (DOD) and $701,000 Federal Emergency Management Agency (FEMA) studies. “These studies will be the first to be led by a Doctor of Chiropractic at a major university that will attempt to identify the preventive outcomes of applying specific exercise interventions amongst firefighters and soldiers.”
Each study will be conducted in several phases carried out over the next few years.
With research already in progress, the FEMA study will include 106 participants headquartered at a Tampa, Fla., fire department. Participants will undergo 24 weeks of bi-weekly supervised training sessions consisting of particular stability and resistance exercises with the goal of improving back muscular endurance — commonly documented as a direct link to back pain.
Expected to begin in spring 2012, the DOD study will include 600 active duty US Army soldiers and will provide a perspective that complements traditional directions of treatment-focus. Instead, the study will assess preventive methods by implementing and evaluating targeted high intensity exercise interventions designed to strengthen the back extensor muscles.
Chiropractic engagement with regards to specific exercise interventions and their potential to prevent back conditions has continued to gain momentum,” says Mayer. “Federal agencies are now recognizing the skills of Doctors of Chiropractic to address prevention and treatment of back injury for our national heroes.”
To learn more about either study, visit www.health.usf.edu.






 

Monday, November 14, 2011

Functional Knee Brace after Anterior Cruciate Ligament Reconstruction not recommended.

I have often expressed my personal dislike of the over use of bracing in general and feel that in most cases it is over utilized. This study supports my previous statements that functional knee brace's are not helpful and we should focus on Rehabilitation not bracing. 

A Randomized Controlled Trial Comparing the Effectiveness of Functional Knee Brace and Neoprene Sleeve Use After Anterior Cruciate Ligament Reconstruction

  1. Trevor B. Birmingham, PhD,,*
  2. Dianne M. Bryant, PhD,,
  3. J. Robert Giffin, MD, FRCS(C),
  4. Robert B. Litchfield, MD, FRCS(C),,
  5. John F. Kramer, PhD
  6. Allan Donner, PhD, and 
  7. Peter J. Fowler, MD, FRCS(C),
+Author Affiliations
  1. From the Fowler Kennedy Sport Medicine Clinic, and the University of Western Ontario, London Ontario, Canada
  1. Address correspondence to Trevor B. Birmingham, PhD, School of Physical Therapy, Faculty of Health Sciences, University of Western Ontario, London, Ontario, Canada N6G 1H1 (e-mail: tbirming@uwo.ca).

Abstract

Background: Despite a lack of evidence for their effectiveness, functional knee braces are commonly prescribed to patients after anterior cruciate ligament (ACL) reconstruction.
Purpose: This trial was conducted to compare postoperative outcomes in patients using an ACL functional knee brace and patients using a neoprene knee sleeve.
Hypothesis: Patients using a brace will have superior outcomes than those using a sleeve.
Study Design: Randomized controlled clinical trial; Level of evidence, 1.
Methods: One hundred fifty patients were randomized to receive a brace (n = 76) or neoprene sleeve (n = 74) at their 6-week postoperative visit after primary ACL reconstruction with hamstring autograft. Patients were assessed preoperatively, then 6 weeks and 6, 12, and 24 months postoperatively. Outcome measures included disease-specific quality of life (Anterior Cruciate Ligament–Quality of Life [ACL-QOL] Questionnaire), anterior tibial translation (KT-1000 arthrometer side-to-side difference), the single-limb forward hop test (limb symmetry index), and Tegner Activity Scale. Outcomes at 1 and 2 years were compared after adjusting for baseline scores. Subjective ratings of how patients felt while using the brace/sleeve were also collected for descriptive purposes using a questionnaire. Four a priori directional subgroup hypotheses were evaluated using tests for interactions.
Results: There were no significant differences between brace (n = 62) and sleeve (n = 65) groups for any of the outcomes at 1- and 2-year follow-ups. Adjusted mean differences at 2 years were as follows: −0.94 (95% confidence interval [CI], −7.52 to 5.64) for the ACL-QOL Questionnaire, −0.10 mm (95% CI, −0.99 to 0.81) for KT-1000 arthrometer side-to-side difference, −0.87% (95% CI, −8.89 to 7.12) for hop limb symmetry index, and −0.05 (95% CI, −0.72 to 0.62) for the Tegner Activity Scale. Subjective ratings of confidence in the knee provided by the brace/sleeve were higher for the brace group than the sleeve group. Subgroup findings were minimal. Adverse events were few and similar between groups.
Conclusions: A functional knee brace does not result in superior outcomes compared with a neoprene sleeve after ACL reconstruction. Current evidence does not support the recommendation of using an ACL functional knee brace after ACL reconstruction.

Keywords:

Footnotes




 

Wednesday, November 9, 2011

Blood Donation, Recovery and Peak Aerobic Power.

Interesting little study!


Time Course for Recovery of Peak Aerobic Power After Blood Donation

Judd, TB, Cornish, SM, Barss, TS, Oroz, I, and Chilibeck, PD. Time course for recovery of peak aerobic power after blood donation. J Strength Cond Res 25(11): 3035–3038, 2011—

Peak aerobic power (V̇O2peak) is decreased after blood donation, but the time course for full recovery is unknown. We measured V̇O2peak and exercise time to fatigue before and weekly for 4 weeks after 450-ml blood donation at a blood donor clinic, to determine the time course of recovery. Twelve moderately active individuals (2 women, 10 men; 24.3 ± 5.2 years) of average aerobic fitness (based on their V̇O2peak relative to normative values) completed V̇O2peak exercise tests before donation, the day after donation, and at weekly intervals for 4 weeks after donation. V̇O2peak was determined by an incremental exercise test on a cycle ergometer. At baseline, mean absolute and relative V̇O2peak values were 4.06 ± 0.92 L·min−1 and 46.6 ± 7.0 ml·kg−1·min−1, respectively. V̇O2peak was significantly decreased on day 1 (3.85 ± 0.89 L·min−1; 44.0 ± 6.5 ml·kg−1·min−1) and during week 2 (3.91 ± 0.97 L·min−1; 44.5 ± 7.2 ml·kg−1·min−1) after blood donation (p < 0.05), and recovered at week 3 after donation. Time to fatigue and peak heart rate were not significantly affected by blood donation. 

We conclude that blood donation causes a significant decrease in V̇O2peak for between 2 and 3 weeks. The practical application of this study is that aerobic power in people of average fitness will be decreased, up to 3 weeks after donating blood. Despite this, there is no effect of blood donation on performance as measured by time to fatigue during an incremental test on a cycle ergometer.


 

Monday, November 7, 2011

NFL and Hamstring injuries why so many this year?


Why so many Hamstring injuries in NFL this Year? Most of these types of injuries occur in players that are at high speed positions and during the the short preseason. Now if you take away access to proper training during the off season by the  trainers on their teams and sprinkle in almost no off season preparation and a shorted preseason you have a recipe for disaster. I would also add that the injury rate has increased overall this season compared to previous season for the very same reason. The body does not like it when it is rushed in its development. For those of you that have heard me lecture on this topic you are familiar with the concept that it take a greater amount of time for ligaments and tendon insertions to increase in tensile strength then for muscles to gain in power and strength. So if this process is rushed you will see that either the tendon or ligaments begin to fail with micro tears that can develop into more serious injuries. This study was published in April of this year take a look!


Hamstring Muscle Strains in Professional Football Players

A 10-Year Review


  1. Marcus C. C. W. Elliott, MD*
  2. Bertram Zarins, MD
  3. John W. Powell, PhD, ATC and 
  4. Charles D. Kenyon

  1. *Peak Performance Project, Santa Barbara, California
  2. Department of Orthopaedic Surgery, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts
  3. Graduate Athletic Training Program, Michigan State University, East Lansing, Michigan
  4. Investigation performed at Peak Performance Project, Santa Barbara, California
  1. §Charles D. Kenyon, Peak Performance Project, 110 Santa Barbara Street, Santa Barbara, CA 93101 (e-mail: charlie.kenyon@gmail.com).

Abstract

Background: Investigations into hamstring strain injuries at the elite level exist in sports such as Australian Rules football, rugby, and soccer, but no large-scale study exists on the incidence and circumstances surrounding these injuries in the National Football League (NFL).
Hypothesis: Injury rates will vary between different player positions, times in the season, and across different playing situations.
Study Design: Descriptive epidemiology study.
Methods: Between 1989 and 1998, injury data were prospectively collected by athletic trainers for every NFL team and recorded in the NFL’s Injury Surveillance System. Data collected included team, date of injury, activity the player was engaged in at the time of injury, injury severity, position played, mechanism of injury, and history of previous injury. Injury rates were reported in injuries per athlete-exposure (A-E). An athlete-exposure was defined as 1 athlete participating in either 1 practice or 1 game.
Results: Over the 10-year study period 1716 hamstring strains were reported for an injury rate (IR) of 0.77 per 1000 A-E. More than half (51.3%) of hamstring strains occurred during the 7-week preseason. The preseason practice IR was significantly elevated compared with the regular-season practice IR (0.82/1000 A-E and 0.18/1000 A-E, respectively). The most commonly injured positions were the defensive secondary, accounting for 23.1% of the injuries; the wide receivers, accounting for 20.8%; and special teams, constituting 13.0% of the injuries in the study.
Conclusion: Hamstring strains are a considerable cause of disability in football, with the majority of injuries occurring during the short preseason. In particular, the speed position players, such as the wide receivers and defensive secondary, as well as players on the special teams units, are at elevated risk for injury. These positions and situations with a higher risk of injury provide foci for preventative interventions.

Keywords:




Am J Sports Med April 2011vol. 39 no. 4 843-850
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