Asian Journal of Sports Medicine
Volume:4 Issue: 2, Jun 2013

Patellofemoral pain syndrome (PFPS) is a very common disorder of the knee. Due to multiple forces influencing the patellofemoral joint, clinical management of this ailment is particularly intricate. Patellofemoral pain syndrome has a multifactorial nature and multiple parameters have been proposed as potential risk factors, classified as intrinsic or extrinsic. Some of the intrinsic risk factors are modifiable and may be approached in treatment. A number of modifiable risk factors have been suggested, including quadriceps weakness, tightness of hamstring, iliopsoas and gastrosoleus muscles, hip muscles dysfunction, foot overpronation, tightness of iliotibial band, generalised joint laxity, limb length discrepancy, patellar malalignment and hypermobility. In general, the routine approach of physicians to this problem does not include assessment and modification of these risk factors and therefore, it may negatively affect the management outcomes. Changing this approach necessitates an easy and practical protocol for assessment of modifiable risk factors and effective and feasible measures to address them. In this review, we aimed to introduce assessment and intervention packages appropriate for this purpose.

Training attendance is an important variable for attaining optimal results after a resistance training (RT) program, however, the association of attendance with the gains of muscle strength is not well defined. Therefore, the purpose of the present study is to verify if attendance would affect muscle strength gains in healthy young males. Ninety two young males with no previous RT experience volunteered to participate in the study. RT was performed 2 days a week for 11 weeks. One repetition maximum (1RM) in the bench press and knee extensors peak torque (PT) were measured before and after the training period. After the training period, a two step cluster analysis was used to classify the participants in accordance to training attendance, resulting in three groups, defined as high (92 to 100%), intermediate (80 to 91%) and low (60 to 79%) training attendance. According to the results, there were no significant correlations between strength gains and training attendance, however, when attendance groups were compared, the low training attendance group showed lower increases in 1RM bench press (8.8%) than the other two groups (17.6% and 18.0% for high and intermediate attendance, respectively). Although there is not a direct correlation between training attendance and muscle strength gains, it is suggested that a minimum attendance of 80% is necessary to ensure optimal gains in upper body strength.

To compare the chromatic contrast sensitivity function (CSF) for the blue-yellow opponent channel (BYOC) between female badminton players and non-athlete controls. We recruited 40 young females (18-25 years old) who played badminton for at least 5 consecutive years as the test group, and 30 age-matched female controls who had no history of regular physical activity. The Pattern Generator™ system was used to test the CSF for the BYOC which was performed at three spatial frequencies (SFs) of 2 cycles per degree (cpd), 5 cpd, and 25 cpd. Comparison of BYOC thresholds showed significantly better results in the test group for all three SFs (P<0.001). Band pass shift (better CSF in the middle SF) was seen in the test group. The control group had low pass (better CSF in the low SF). Ocular motility (heterophoria, fusional convergence and divergence at far and near distances, and near point of convergence) was better in the test group, but the inter-group difference was not significant. The BYOC threshold results for badminton players indicated a better visual performance which may be a result of enhanced performance of the parallel processing of the parvocellular and magnocellular systems. This may be inherent and/or acquired in badminton players. In addition, badminton players appear to have developed sensory-motor programmed activities. Testing the CSF for BYOC may be useful for athlete selection in different levels and/or used as a criterion for screening players in the field of badminton.

Purppose: The aim of this study was to assess the effects of a six-month pedometer-based workplace intervention on changes in resting blood pressure (BP) and Cardiorespiratory fitness (CRF). A subsample of ASUKI Step participants (n= 355) were randomly selected to have changes in their BP and CRF monitored during the intervention. Pedometers were used to monitor steps taken with a goal of walking more than 10,000 steps/day. Systolic and diastolic BP were taken using an Omron automated BP cuff. Estimated VO2 max was obtained using the Åstrand-Rhyming cycle ergometer test. A multi-level growth modeling approach, and a mixed model ANOVA were used to predict changes in systolic and diastolic BP, and estimated VO2 max over time by steps, age, gender, and university site. Steps/day averaged 12,256 (SD = 3,180) during month 1 and steadily decreased to month 6. There were significant linear and quadratic trends in systolic and diastolic BP over time. Age was positively related to initial starting values for systolic and diastolic BP, and approached significance for systolic BP changes over time. Steps/day approached significance for linear changes in systolic BP. There was a significant difference between ASU and KI participants’ estimated VO2 max. There was a significant change over time in the estimated VO2 max. The number of steps taken was significantly related to changes in estimated VO2 max over time. The results of the present study indicate that healthy individuals who took part in a pedometer intervention improved several cardiovascular disease risk factors.

This study aims to investigate the association between the rating of perceived exertion (RPE), heart rate (HR) and the blood lactate concentration ([La]) in successive judo fight simulations (randori). Ten athletes participated in the study (age: 25.6±2.1 years; stature: 1.75±0.07 m; body mass: 75.6±14.9kg; %BF: 11.5±7.8%; practice: 14.5±6.2 years) and completed 4 judo fight simulations (T1 to T4) with duration of 5 min separated by 5 min passive recovery periods. Before each randori, [La] and HR were collected, and after each randori, the same measures and the RPE (CR-10 scale) were collected. Significant correlations were observed between: (1) CR-10 and HR (T2: r =0.70; T3: r =0.64; both, P<0.05); (2) ΔCR-10 and Δ[La] (T1-T2: r =. 71, P< 0.05; T2-T3: r =0.92, P<0.01; T3-T4: r =0.73, P<0.05). Moreover, significant differences were noted in the behavior of the HR between the 2nd (T2) and 3rd (T3) judo fight simulations (P<0.05). The use of CR-10 in the evaluation process, as well as in deciding the load of training in judo, should be done with caution.

The aim of this study was to investigate whether supplementation of carbohydrate together with peptide glutamine would prevent anaerobic power decrease during repeated competitions. Twenty-eight physical education male students voluntarily participated in the study. Subjects were randomly divided on a Maximal power (Max power) output value basis to four groups: 1) G group (Oral ingestion of glutamine at the dose of 0.25 g/kg body mass in 250 ml of water), 2) M group (A single carbohydrate at a concentration of 50g of maltodextrin in 250 ml of water), 3) GM group (Carbohydrate at a concentration of 50g of maltodextrin + Glutamine at the dose of 0.25 g/kg body mass in 250 ml of water) and, 4) P group (Just 250 ml of water and 30 gram sweetener). Each subject performed three times Running-based Anaerobic Sprint Test (RAST) with intervals of 1 hour. Max power, Minimal power (Min power) and Fatigue index were calculated for each participant. There was a significant decrease in Max and Min power in P group in time series (P< 0.05). Furthermore, regarding the Max and Min power, there was significant difference between P and GM group in third bout indicating stronger influence of combination of maltodextin and glutamine in comparison with pure consumption of glutamine and maltodextrin (P< 0.05). It seems acute supplementation of glutamine and maltodextrin combination, 2 hours before exercise is more efficient in storing glycogen than consumption of a pure carbohydrate or glutamine and consequently prevents decline of anaerobic power in repeated bouts of RAST protocol better than pure maltodextrin or glutamine.

The present study aims at investigating the physiological response and technical-tactical parameters in Brazilian jiu-jitsu competition. The study included 35 male Brazilian jiu-jitsu athletes (adult category, body mass: 80.2 ± 13.0 kg), graded from white to brown belt, during combats fought at regional level. Twenty-two fights were analyzed in terms of technique and time structure. Blood glucose, lactate and maximal isometric grip strength were determined before and after the fights. The rate of perceived exertion was also assessed after the fight, using the 6-20 Borg rating. The fights were recorded and the following variables were determined: the exertion/pause ratio and subjective intensity of actions, categorized between low and high intensity. The results indicated that during Brazilian jiu-jitsu fights, the glycolytic pathway is only moderately activated (lactate before: 4.4 (4.0 – 4.6) mmol/L, after: 10.1 (8.0 – 11.3) mmol/L; glucose before: 112.4 ± 22.3 mg/dL, after: 130.5 ± 31.0 mg/dL). The exertion during the fight resulted in significant reductions in handgrip strength (right hand grip before: 45.9 ± 10.3 kgf, after: 40.1 ± 9.5 kgf; left hand grip before: 44.2 ± 11.1 kgf, after: 37.0 ± 10.2 kgf). The athletes rated the fight as hard: 15 (13 – 15). Effort/pause ratio was 6:1, while high-intensity actions lasted approximately 4 s, resulting in a low/high intensity? ratio of 8:1. It is recommended that coaches direct the training loads to simulate the energy demand imposed by the competitive matches, activating moderately the glycolytic pathway. Moreover, the time structure of combats can be used to prescribe both physical and technical-tactical training.

The aim of this study was to investigate eccentric torque production capacity of the ankle, knee and hip muscle groups in patients with unilateral chronic ankle instability (CAI) as compared to healthy matched controls. In this case-control study, 40 participants (20 with CAI and 20 controls) were recruited based on convenient non-probability sampling. The average peak torque to body weight (APT/BW) ratio of reciprocal eccentric contraction of ankle dorsi flexor/plantar flexor, ankle evertor/invertor, knee flexor/extensor, hip flexor/extensor and hip abductor/adductor was determined using an isokinetic dynamometer. All subjects participated in two separate sessions with a rest interval of 48 to 72 hours. In each testing session, the torque production capacity of the ankle, knee, and hip muscle groups of only one lower limb was measured. At first, 3 repetitions of maximal eccentric-eccentric contraction were performed for the reciprocal muscles of a joint in a given movement direction. Then, the same procedure of practice and testing trials was repeated for the next randomly-ordered muscle group or joint of the same limb. There was no significant interaction of group (CAI and healthy controls) by limb (injured and non-injured) for any muscle groups. Main effect of limb was not significant. Main effect of group was only significant for eccentric torque production capacity of ankle dorsi flexor and hip flexor muscle groups. The APT/BW ratio of these muscles was significantly lower in the CAI group than the healthy controls (P<0.05). CAI is associated with eccentric strength deficit of ankle dorsi flexor and hip flexor muscles as indicated by reduction in torque production capacity of these muscles compared to healthy controls. This strength deficit appeared to exist in both the injured and non-injured limbs of the patients.

When assessing fitness levels, body composition is usually measured. The purpose of this study was to determine the overall efficacy of a body mass index (BMI) equation for predicting body composition with respect to college aged participants. Body composition was measured using dual-energy x-ray absorptiometry (DXA) and was estimated using the Womersley and Durnin BMI prediction equation. There was no significant (P=0.8) percent body fat (%BF) difference between the BMI prediction equation and DXA (BMI Predicted=25 (10) [min=6; max=52] %BF vs. DXA=25 (6) [min=10; max=45] %BF). In addition, a significant correlation was found between the two approaches (r=0.791, P=0.001). However, both the SEE (6.32 %BF) and TE (6.63 %BF) were outside acceptable ranges for prediction equations. The Womersley and Durnin equation for estimating %BF was not found to be a good estimate. Therefore, although the BMI predicted %BF has been previously found to predict skinfold estimated %BF, it does not appear valid in estimating %BF from DXA.

Platelet-rich plasma (PRP) is derived from centrifuging whole blood to obtain a high platelet concentration containing numerous growth factors. Despite its widespread use, there is still a lack of high-level evidence regarding randomized clinical trials assessing the efficacy of PRP in treating ligament injuries. Although there is research showing an improvement in the early stages of healing in the animal model of acute medial collateral ligament (MCL) injury of the knee, there is no strong evidence to support the efficacy of PRP injections for treating MCL lesions in humans. In this report, we present a case of an elite football player, treated with multiple PRP local injections followed by rehabilitation, for a high grade MCL lesion of the knee. He was able to resume training at day 18, painfree, with full range of motion and the ability to complete a functional test based on all sport specific movements. He played matches at 25 days with no residual symptoms or functional deficit. There were no further complaints or recurrences at the 16 months follow up. On the basis of this report, we can assume that the treatment of high grade acute MCL lesions of the knee with PRP is a promising therapeutic option to be further explored with good quality Randomized Controlled Trials (RCTs).