SPRING 2012: VOLUME 5 ISSUE 1
In this issue:
- Scapular muscle recruitment during therapeutic exercise.
David Wallace, Scott Carabello, Nick Chaber.
- Understanding the causes, prevention and treatment of osteoporosis (part 2): detecting and diagnosing the disease.
Adam Hawkey
- Research Concepts and Methods (part 4).
David Jenkins
- The characteristics of professional and semi- professional football players following off-season and pre-season training periods.
Julian Smith, David Morrison.
- Convulsive syncope following acupuncture treatment: a case study.
Tim Trevail.
- Weight loss and dehydration level in English elite male futsal players.
Daniel Berdejo-del-Fresno.
- Effects of limb dominance and ankle bracing on lateral peak impact forces and performance measures in basketball.
Adam Hawkey, Ian Lahart, Alan Nevill.
The characteristics of professional and semi-professional football players following off-season…
by Julian Smith and David Morrison
The current was a within and between group repeated measures comparison of the performance of professional and semi-professional football players following off-season and pre-season training periods on a battery of fitness tests. Following ethical approval, 23 professional and 16 semi-professional male football players completed informed consent and medical questionnaires. Participants completed two testing sessions, immediately following the off-season and 6-week pre-season training periods. A mixed design group (playing level) by time MANOVA indicated an effect for differences in performance over time (Wilks lambda 7,28 = .20, P < .01, Partial Eta2 = .90) and an interaction effect for differences in performance over time by playing level (Wilks lambda 7,28 = .20, P < .01, Partial Eta2 = .80). Univariate follow-up tests indicated effects for differences over time in body fat (F 1,44 = 54.62, P < 0.01, Partial Eta2 = .62), 15m sprint time (F 1,44 = 67.96, P < 0.01, Partial Eta2 = .67), anaerobic endurance (F 1,44 = 18.17, P < 0.01, Partial Eta2 = .35), and the YIET (F 1,44 = 46.98, P < 0.01, Partial Eta2 = .58). Interaction effects were indicated for differences in body fat (F 1,44 = 25.78, P < .01, Partial Eta2 = .43), 15m sprint time (F 1,44 = 71.36, P < .01, Partial Eta2 = .68), anaerobic endurance (F 1,44 = 5.32, P = .03, Partial Eta2 = .14), and agility (F 1,44 = 5.78, P = .02, Partial Eta2 = .15), over time by playing level. With the exception of 15m sprint time, all interaction effects were due to the greater improvements over time of the semi-professional players. Pre-season training programmes may lack sufficient specificity to illicit adaptations in certain key fitness components. Consequently, football players may be commencing the playing season without the necessary levels of conditioning.
Scapular Muscle Recruitment during Therapeutic Exercise
by David Wallace, Scott Carabello and Nick Chaber
Proprioceptive neuromuscular facilitation (PNF) patterns have been used to improve muscle strength and may facilitate muscle recruitment patterns typically seen during overhead activities. The purpose of this study is to compare scapula muscle activity during commonly used scapular strengthening exercises. Ten healthy men and twenty healthy women between the ages of 18 and 23 participated in the study (n=30, mean age 23±4 yrs., mean height 1.69±0.16m, mean mass 72.6±15 kg). Prior to enrollment in the study, subjects were screened for inclusion and exclusion criteria, which included no history of shoulder pathology were recruited for this study.Allparticipants performed the following exercises while surface EMG recorded the activity of the scapula muscles: (1) seated row, (2) push-up with a plus, (3) D1 flexion PNF and (4) D2 flexion PNF pattern. The main outcome measures were:average percent maximum voluntary isometric contraction (MVIC) of middle trapezius, lower trapezius, upper trapezius and serratus anterior muscle during each exercise.When performing the D2 PNF exercise, middle trapezius was more active compared to the row (p=0.012) and the D1 PNF exercise (p<0.001). There were no differences in serratus anterior activity (p>
0.05). The ratio between upper trapezius to lower trapezius was higher during the PNF exercises versus the throw (p<0.05). These results suggest that the D2 flexion exercise is most efficient for recruiting the middle trapezius and serratus anterior, but it does not encourage ideal intramuscular activation of the scapular muscles as compared to an overhead activity.
Understanding the causes, prevention, and treatment of osteoporosis (part 2)...
by Adam Hawkey
Osteoporosis is a multifactorial disease characterised by low bone mineral density (BMD), a disruption of the normal bone architecture, and increased risk of fracture. Common sites of osteoporotic fracture include the spine, hip, and forearm, with 1,150 people reportedly dying each month in the UK as a result of hip fracture. Worldwide the incidence of hip fractures is expected to more than triple from 1.66 million in 1990 to 6.26 million in 2050, while in the European Union an increase from 414 000 to 972 000 cases per annum is expected over the next 50 years. Osteoporosis is diagnosed clinically as a BMD of 2.5 standard deviations (SD) or more below the average for the young healthy female population. Therefore, BMD measurement is fundamental in assessing osteoporosis risk; comparable to measuring blood pressure to predict stroke and substantially better than measuring serum cholesterol to predict cardiovascular disease respectively. BMD is most commonly measured, at the hip or lumbar spine, using dual-energy x-ray absorptiometry (DXA). Measurements at other sites (primarily the heel and finger) using peripheral DXA or ultrasound is also possible, although not considered as accurate. Recently, other methods of analysis have become available, including micro- computed tomography (microCT) and quantitative computed tomography (QCT), which are able to better distinguish between trabecular and cortical bone. However, DXA is currently considered the gold standard for BMD measurement as it is accurate, precise, requires only a short scanning period, and has a limited radiation dose. The purpose of this article (the second of a four-part feature) is to define osteoporosis and its parameters, discuss the devastating impact is has on individuals and society, and explain the diagnostic methods used to quantify bone density.
Weight loss and dehydration in English Futsal players
by Daniel Berdejo-del-Fresno, University of Manchester, UK
Futsal is a high intensity intermittent sport in which accelerations and short sprints are performed at maximal or almost maximal intensity, interspersed by brief recovery periods, during a period of time relatively long. Hydration is the word used to define the process of decrease in the amount of body water. Any activity that causes dehydration will provoke a decrease in the physical performance. An easy way to know the dehydration level of a sportsman is to weigh the subject before and after practising sport. The current study investigates the dehydration level of elite English male futsal players, in two games (i.e. friendly vs. official) and evaluates the resulting values by using studies available in the literature. Eleven (n=11) elite level male futsal players from a top-2 team competing in the Football Association (FA) Futsal National League volunteered to participate in this study. The anthropometric tests used were: mass, height and BMI. Body mass (kg) was recorded before the warm-up and after the game, the subjects wearing only underwear. Besides, the percentage of mass loss, activity time and sweating rate was also calculated. The average activity time was 48.18 ± 3.89 minutes (friendly game) and 48.18 ± 13.47 minutes (official game), with a mean mass loss of 1.27 ± 1.08 kg and 1.09 ± 0.94 kg, respectively. The mass loss percentage was 1.75 ± 1.53% and 1.47 ± 1.22%, respectively. The sweating rate was higher in the official game than in the friendly (11.17 mL/min and 10.44 mL/min). Significant differences were not found in the dehydration level between the two types of game in an elite level English Futsal team. Nevertheless, the results showed that these players obtained a dehydration level that could affect their performance.
Effects of limb dominance and ankle bracing on lateral peak impact forces and performance measures..
by Hawkey A., Lahart I., and Nevill A.
Ankle injuries are frequently suffered by basketball players. While ankle bracing has been reported to reduce injury incidence, research is limited regarding lateral peak impact forces (LPIF) and limb dominance. There is also equivocal evidence of ankle bracing’s effect on basketball-specific performance. Eight male national league basketball players (n=8) performed 45o cutting manoeuvres, at 4.5m/s to 5.5m/s, past a static defensive opponent on dominant and non-dominant sides; both braced (Aircast Airsport) and un-braced. A further 10 players (n=18; mean + SD, age = 20 + 6 yrs; weight = 720 + 161 N; height = 1.83 + 0.17 m), performed basketball-specific performance tests (20m sprint, agility, and vertical jump tests) in both braced and un-braced conditions. Two-way analysis of variance (ANOVA) with repeated measures revealed significant differences (P = 0.001) between LPIF on dominant (Mean = 639.46 N, SE = 20.6 N) and non-dominant limbs (Mean = 728.96 N, SE = 17.6 N). ANOVA also revealed significant differences (P = 0.005) between LPIF in braced (Mean = 658.15 N, SE = 17.4 N) and un-braced conditions (Mean = 710.27 N, SE = 19 N). Paired-sample T-test reported no significant difference (P = 0.6) in 20m Sprint times with (Mean = 3.22 s, SE = 0.03 s) and without bracing (Mean = 3.23 s, SE = 0.03 s). No significant difference (P = 0.78) was reported in Agility performance with (Mean = 20.46 s, SE = 2.4 s) and without bracing (Mean = 20.51 s, SE = 2.48 s). No significant difference (P = 0.28) was reported in Jump performance braced (Mean = 0.62 m, SE = 0.002 m) and un-braced (Mean = 0.61 m, SE = 0.002 m). Current study suggests using a semi-rigid ankle brace reduces LPIF to the ankle-foot complex, potentially limiting ankle injury without impairing basketball-specific performance.
Editorial: Quantification, clarification and standardisation of whole body vibration.
by Adam Hawkey
Vibration is defined as a mechanical stimulus characterised by a recurring oscillatory motion back and forth over the same pattern. We experience vibration throughout our daily lives when driving a car or operating machinery with motorised parts, and exposure is traditionally associated with negative effects on the human body. However, whole body vibration (WBV) is an intervention that has gained popularity in both the medical and sporting arenas in recent years. Despite its popularity though, it would appear that our understanding of how human systems respond to these vibratory signals lags somewhat behind the availability of the WBV platforms used for training, and that inconsistencies and inaccuracies reported regarding WBV have the potential to limit the replication and development of research. There is also concern that researchers, by inadvertently using incorrectly reported protocols from previous studies, may unknowingly expose participants to harmful interventions. The aim of this editorial, therefore, is to quantify, clarify, and standardise the terminology used to describe WBV training.
Research Concepts and Methods – 4
by David Jenkins
At the conclusion of the third part of this series, Research Concepts and Methods – 3, I pointed to the first of four combinations of research methodology constructs, that of quantitative outputs for analysis generated via statistical methods directly from quantitative data inputs. This article offers an overview of the nature and characteristics of this type of research, and also outlines some of the major considerations that need to be addressed before embarking on any data collection for such work. I am not attempting to describe or explain individual quantitative or statistical methods – there are myriad textbooks (see my short list of recommended texts below), available at all levels of study for these purposes – my aim here is to outline the main underpinning concepts relating to quantitative inputs and outputs;and, for convenience, and within the context of this, I also use the terms statistics and quantitative inputs and outputs interchangeably.With this in mind, I set out below the following sections: a closer examination of the statistical utility framework illustrated in the previous article (Research Concepts and Methods-3Journal of Sports TherapyVol. 3 Issue. 3);an introduction to the main parameters for testing hypotheses; the relationship between samples and populations; and some concluding remarks.
Research Concepts and Methods – 4
by David Jenkins
At the conclusion of the third part of this series, Research Concepts and Methods – 3, I pointed to the first of four combinations of research methodology constructs, that of quantitative outputs for analysis generated via statistical methods directly from quantitative data inputs. This article offers an overview of the nature and characteristics of this type of research, and also outlines some of the major considerations that need to be addressed before embarking on any data collection for such work. I am not attempting to describe or explain individual quantitative or statistical methods – there are myriad textbooks (see my short list of recommended texts below), available at all levels of study for these purposes – my aim here is to outline the main underpinning concepts relating to quantitative inputs and outputs;and, for convenience, and within the context of this, I also use the terms statistics and quantitative inputs and outputs interchangeably.With this in mind, I set out below the following sections: a closer examination of the statistical utility framework illustrated in the previous article (Research Concepts and Methods-3Journal of Sports TherapyVol. 3 Issue. 3);an introduction to the main parameters for testing hypotheses; the relationship between samples and populations; and some concluding remarks.
Convulsive syncope following acupuncture treatment: a case study
by Tim Trevail
The incidence of adverse events following acupuncture has been described as minimal. However, there are reports of patients undergoing acupuncture suffering from a transient loss of consciousness and upright posture due to global cerebral ischemia; known as convulsive syncope. The current study concerns a 21 year old male patient who was receiving acupuncture treatment for medial tibial stress syndrome. He developed a case of convulsive syncope immediately following the treatment. The patient was referred to a specialist registrar in cardiology. He was then subjected to a range of laboratory tests, including an exercise induced stress test measuring heart rate and blood pressure, which revealed no abnormalities. Consequently, the patient was cleared to return to sport. This current case study suggests a wider consideration is needed to include the athletic population who may have been recently subjected to any of the aforementioned stresses.