Physical therapy in sport: official journal of the Association of Chartered Physiotherapists in Sports Medicine

Published by Elsevier
Online ISSN: 1466-853X
Publications
Article
To examine the relationship and differences between static and dynamic postural stability in healthy, physically active adults. Descriptive laboratory study. Research laboratory. Ten females (age: 21.6 ± 1.2 yrs, mass: 60.8 ± 7.6 kg, height: 165.0 ± 5.0 cm) and ten males (age: 25.1 ± 3.0 yrs, mass: 73.9 ± 8.7 kg, height: 173.5 ± 9.0 cm). Static postural stability was measured during a single-leg standing task (standard deviation of the ground reaction forces). Dynamic postural stability was measured during a single-leg landing task using the Dynamic Postural Stability Index. Pearson's r-coefficients were calculated to examine relationships between the two tests and a one-way ANOVA was calculated to examine potential differences in test scores (p < 0.05). None of the Pearson's r-coefficients achieved statistical significance. The one-way ANOVA and post hoc comparisons demonstrated that dynamic postural stability scores were significantly higher than static postural stability scores. A lack of a correlation between static and dynamic measures and increase in difficulty during dynamic measures indicates differences in the type and magnitude of challenge imposed by the different postural stability tasks. The more challenging dynamic measures of postural stability may be more suitable for prospective studies examining risk of ankle and knee injury in healthy, physically active individuals.
 
Characteristics of handball players and control participants.
Conventional strength ratios in control participants and athletes grouped according to age. 
Functional strength ratios in control participants and athletes grouped according to age. 
Article
Objectives: To evaluate the external (ER) and internal rotator (IR) muscles' isokinetic peak torque and conventional and functional strength ratios in handball players and controls of different ages. Design: Cross-sectional and descriptive analysis. Setting: Exercise Physiology Laboratory. Participants: A total of 228 participants (108 athletes and 120 controls) were divided into five groups according to age, ranging from 13 to 36 years old. Main outcome measures: Isokinetic tests were performed concentrically at 60 and 300 deg s(-1) and eccentrically at 300 deg s(-1). Results: The differences between the athletes and controls regarding the peak torque of the ER and IR muscles were significant in males older than 18 years. The peak torque of the IR and ER muscles increased significantly across age in male athletes, but not in female athletes, except in the case of ER peak torque, which differed significantly between 13 and 16 years old. The female athletes presented higher conventional ratios (0.81 ± 0.07) than males (0.66 ± 0.08). Values represent means and standard deviations. Athletes and controls showed mean functional strength ratios below 1.0. Conclusions: Although there were no muscular ratio differences between the athletes and the controls, their ratio values were below the literature-recommended reference values to prevent shoulder injuries.
 
Percentage of injuries by pathology. 
Percentage of injuries by anatomical location.
Percentage of physiotherapeutic procedures utilized.
Article
The purpose of this study was to assess the profile of the treatments performed at the physiotherapy department of the Brazilian Olympic Committee during the 2007 Pan-American Games. Observational study. Participants in this study included 434 athletes from the Brazilian Olympic Committee who were referred by the Brazilian medical department to the Brazilian physiotherapy department. The treatment registers were done in a standard form and stored for computer analysis and descriptive statistics calculation. Most athletes of the Brazilian delegation needed physiotherapeutic treatment (n=434, 65.7%), and approximately one quarter of the athletes went to the Games with a previous injury (n=146, 22.1%). The main complaints observed during the treatments were spine-related pathologies (lumbar pain, thoracic and cervical pain) (n=89, 25.3%), tendinopathy (n=79, 22.4%), and muscle strain (n=43, 12.2%), among others. There were 2523 physiotherapeutic treatments performed, and the most utilized procedures were kinesiotherapy, which represented 24.9% (n=969) of all the procedures performed, ultrasound (n=757, 19.4%) and cryotherapy (n=670, 17.2%). A large number of athletes required physiotherapy services during the Games. Approximately one quarter of the athletes were injured before the competition started. The main pathologies were spine-related injuries, tendinopathy and muscle strain. The most frequently utilized procedures were kinesiotherapy, ultrasound and cryotherapy.
 
Article
The main objective is to determine whether there are differences in the relative isokinetic and electromyographic responses between the internal rotator (IR) muscles on the dominant and non-dominant sides of tennis players during performance of an isokinetic fatigue protocol. Ten male tennis players were recruited for this isokinetic and electromyographic study. Participants performed 35 concentric maximal voluntary actions, carrying out internal rotations of both shoulders at an angular velocity of 120° s(-1). Maximal torque (T((45°))Max), torque decrease (T((45°))), Root Mean Square normalised (RMSnorm) and Neuromuscular Efficiency (NME) parameters were analysed. Although an increased T((45°))Max was observed on the dominant side compared to the non-dominant side, the progression of torque differences did not indicate differences in fatigue-resistance between the two sides. RMSnorm was also higher on the dominant side compared to the non-dominant side, without showing a fatigue effect. NME values decreased during performance of the fatigue protocol without any side effect. Practicing tennis induces an increased T((45°))Max on the dominant side compared to the non-dominant side, but does not appear to provoke differences in the fatigue-resistance of IR muscles. EMG analysis showed that the fatigue induced was mainly peripheral (from metabolic and ionic changes).
 
Article
Evaluate the effects of a weight-bearing neuromuscular training program on 2D and 3D lower extremity kinematics during a single leg step down. Pre-test, post-test quasi experimental. Laboratory. Sixty nine healthy females performed a single leg step down. The 20 females with the most medial knee orientation during this task participated in this study (20.0 yr (1.6 yr), 167.9 cm (6.0 cm), 63.2 kg (8.3 kg)). 2D knee frontal plane projection angle (FPPA) and 3D lower extremity joint (hip and knee) and segment (pelvis and femur) angles during a single leg step down before and after training were compared using paired t-tests. Pearson correlation coefficients were used to measure the association of 2D and 3D kinematic changes following training. Knee FPPA decreased 4.6° after training (P < 0.001). Hip flexion (P < 0.001) and hip adduction (P = 0.04) increased after training. However, no other 3D joint kinematic changes were observed. Segment angle changes included decreased femoral internal rotation (P = 0.008) and adduction (P = 0.08) and increased anterior pelvic tilt (P < 0.001) and contralateral pelvic drop (P = 0.02). The association between changes in 2D and 3D joint kinematics ranged from 0.12 to 0.34. Exercises intended to improve altered lower extremity kinematics may reduce medial knee 2D FPPA values during a single leg step down. However, this 2D change may not be linked with any specific change in 3D joint kinematics.
 
Article
In sports medicine, muscle strength and joint flexibility of the contralateral limb is used as a rehabilitation goal for the injured extremity. The present study was designed to determine whether side differences in hamstrings and quadriceps muscle strength, or in the ratio between hamstrings and quadriceps strength (H:Q), might be of clinical importance. Cross-sectional study in a randomly selected, population-based cohort. University hospital in Uppsala. Quadriceps and hamstrings strength was assessed by maximum isokinetic concentric contractions at an angular velocity of 90°/s. A sample of 159 randomly selected women from Uppsala county population registers, aged 20-39 years, was included in the study. Peak isokinetic concentric torques of the quadriceps and hamstrings, and the corresponding H:Q ratios. In this cohort of non-athletes the muscle strength in the dominant leg was on average 8.6% (p <0.001) weaker in the knee flexors, but 5.3% (p = 0.009) stronger in the knee extensor as compared with the non-dominant leg. This gives an H:Q ratio in the dominant leg of 46% as compared with 53% (p > 0.001) in the non-dominant leg. Our study shows that in a population-based sample of women there is a significant asymmetry in leg muscle strength favouring non-dominant leg flexion and dominant leg extension. In this study the H:Q ratio was therefore substantially lower in the dominant leg. Whether this should influence rehabilitation goals must be further investigated.
 
Article
To determine whether tester experience influences the reliability of three-dimensional gait collections. Reliability study. Ten healthy subjects visited a university gait laboratory on two separate days and underwent a walking gait analysis. During each visit, kinematic data were collected by a biomechanist with 8 years of 3D gait analysis experience (EXP) and a physical therapist with no previous 3D gait analysis experience (NOV). Joint kinematic angles were calculated using either a functional or predictive joint identification method. Within-tester and between-tester measures of reliability were determined by calculating the root mean square error (RMS) and coefficient of multiple correlations (CMC). Within-tester RMS and CMC values were not significantly different (P > 0.05) between the EXP and NOV testers using either a functional or predictive joint approach. Within-tester CMC values exceeded 0.90 for both testers across all kinematic variables. Between-tester CMC reliability values were greater than 0.85 for all variables measured. Following basic training, a physiotherapy clinician with no previous 3D gait experience is as reliable as an experienced gait biomechanist with respect to marker placement accuracy. In addition, reliability comparisons between an experienced and novice tester appear independent of the joint identification method chosen.
 
Article
To compare the incidence, severity and nature of injuries sustained by Saudi National Team footballers during match-play and training on natural grass and 3rd generation (3G) artificial turf. Injury data was collected on all Saudi National Team players competing at the Gulf Cup (Yemen December 2010: 3G) and the Asian Cup (Qatar January 2011; grass). A total of 49 players were studied (mean ± SD; Age 27 ± 4 yr; body mass 71.4 ± 6.7 kg; height 176.8 ± 6.3 cm; professional playing experience 9 ± 3 yr) of which 31 competed at the Gulf Cup, 32 at the Asian Cup (14 at both). A prospective cohort design was used to investigate the incidence, nature and severity of injuries sustained with data collected using a standardised injury questionnaire. All data were collected by the team physiotherapist with the definition of injury set at any injury that required player and clinician contact. Injury and exposure data were collected and reported for games, training and all football activity. A total of 82 injuries [incidence - 56.1 per 1000 h total game and training exposure] were recorded at the Asian Cup (grass) and 72 injuries [incidence - 37.9 per 1000 h total game and training exposure] were recorded at the Gulf Cup (3G). Incidence data for training, game and all football exposure injury rates were higher when playing on grass. The vast majority of injuries on both surfaces were very minor that, whilst requiring medical attention, did not result in loss of match/training exposure. Injuries that resulted in 1-3 days absence from training or game play had similar incidence rates (Grass: 7.4 vs. 3G: 7.4 injuries per 1000 h exposure). More severe injuries were less frequent but with a higher incidence when playing on grass. Lower limb injuries were the most common in both tournaments with a higher incidence on grass (Grass: 14.2 vs. 3G: 7.9 injuries per 1000 h exposure). Muscle injuries were the most frequent of all injuries with similar incidence rates on both surfaces (Grass: 5.4 vs. 3G: 4.7 injuries per 1000 h exposure). Injuries that involved player contact were also more common on grass (Grass: 11.5 vs. 3G: 3.2 injuries per 1000 h exposure). Whether reporting all injuries or just those that prevented players from taking part in training or match play, injury incidence rates were generally higher when Saudi National Team footballers played on grass than on 3G artificial surface. Although this is a small study, the unique quasi-repeated measures study design with elite Saudi National Team footballers, adds to the current belief that 3G artificial turf does not increase injury risk in football.
 
Article
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). Randomized Control Trial. University laboratory. 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. 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. 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). 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.
 
Article
To compare lateral abdominal muscle thickness between weightlifters and matched controls. A case control study design. University laboratory. 16 female Thai national weightlifters and 16 matched controls participated in this study. Ultrasound imaging with a 12-MHz linear array was used to measure the resting thickness of transversus abdominis (TrA), internal oblique (IO) and total thickness (Total) of lateral abdominal muscle (LAM) on the right side of abdominal wall. The absolute muscle thickness and the relative contribution of each muscle to the total thickness were determined. Weightlifters had significantly thicker absolute TrA and IO muscles than matched controls (p < 0.01). Further, the relative thickness of the IO was significantly greater in weightlifters than matched controls (p < 0.05). The findings of this study suggest that routine Olympic style weight training among female weightlifters appears to result in preferential hypertrophy or adaptation of the IO muscle.
 
Locations of electrodes in the RA and OE (right and left sides) muscles and the RF (right side). (RAUR-Rectus Abdominis upper right, RAUL-Rectus Abdominis upper left; RALR-Rectus Abdominis lower right, RALL-Rectus Abdominis lower left; OER-Obliquus Externus right, OEL-Obliquus Externus left; RF-Rectus Femoris). 
Representative EMG signal register of the RA muscle (upper umbilical-right) in loads of 100%, 80%, 60%, 40%, 20%. 
Article
The aim of this study was to describe by means of surface electromyography the activation of the rectus abdominis, obliquus externus and rectus femoris muscles during the "crunch" abdominal exercise performed with loads. Thirteen subjects performed crunch exercises with loads representing 80, 60, 40 and 20% of the 1-RM (100%) in a random order with the subjects drawing lots, and with a 5 min rest between sets. Surface bipolar EMG electrodes were used. The root mean square of the EMG was calculated for the first repetition of each load. Differences between conditions were tested using a one way ANOVA for repeated measures. Post-hoc Bonferroni tests was used to detect significant differences between specific loads (p<0.05). An average of the percentage values of all studied abdominal muscles was used as a representative value of abdominal synergy (Ab Syn). In general it can be concluded that the abdominal muscles were significantly more recruited in the 100% load condition. Abdominal activation significantly differed between the various loads; however, in general adjacent loads (20 vs. 40% - 1-RM) did not differ. These results suggest that for young, healthy and physically active adults when the objective is progression in the training process of abdominal force, the option ought to be for changes of load superior to 20% of the 1-RM.
 
Article
To offer a three-dimensional description of the scapular kinematics and scapulohumeral rhythm (SHR) in healthy subjects during quasi-static shoulder abduction. To analyze and compare the influence of loaded and unloaded conditions on scapula kinematics and SHR. Eleven subjects were analyzed using videogrammetry and the application of mathematical modelling during quasi-static shoulder abduction positions (intervals of approximately 30 degrees). Scapular kinematic data under unloaded and loaded conditions. The scapula presented external rotation, upward rotation and posterior tilting during the studied movement. Analyzing the scapulohumeral rhythm, different behaviours were observed in the scapular movement planes. Loading condition increased scapular upward rotation and posterior tilt at 60 degrees and 90 degrees of abduction (p>0.01). Analyzed scapular kinematics and scapulohumeral rhythm showed differences between adopted loading conditions. The clinical applications of these findings are discussed.
 
Article
To compare the muscle activity of the abductor hallucis (AbdH) and the medial longitudinal arch (MLA) angle during toe curl (TC) and short foot (SF) exercises while sitting or in one-leg standing position. Two-way repeated-measures ANOVA was used to analyze the effects of exercise type and position on the muscle activity of the AbdH and the MLA angle. Twenty subjects with normal feet participated in this study. The muscle activity of the AbdH and the MLA angle were measured during TC and SF exercises while sitting or in one-leg standing position. The EMG activity of AbdH in SF exercise was significantly greater than during TC exercise in both exercise postural positions (p < 0.001). During the SF exercise, the EMG activity of the AbdH in the one-leg standing position was significantly higher than that while sitting (p < 0.001). The MLA angle in SF exercise was significantly smaller than during TC exercise in both postural positions (p < 0.001). These results suggest that SF exercise is a more useful strengthening exercise than TC exercise in activating the AbdH muscle.
 
Article
Extracorporeal shock wave therapy (ESWT) is becoming a popular method for the treatment of musculoskeletal disorders. We herein report a case of Achilles tendon rupture possibly related to ESWT. A 49-year-old female was treated with a calcaneal osteotomy due to Haglund's disease on the right. However, she developed chronic calcific Achilles tendinopathy postoperatively, and during the following 2 year period after surgery she received various non-steroidal anti-inflammatory drugs and one injection of corticosteroids. She was subsequently treated with extracorporeal shock wave therapy (ESWT), but persistent pain, local swelling and redness over posterior right ankle were noted. Two months after ESWT she experienced an Achilles tendon tear and received Achilles tendon reconstruction. While ESWT is generally considered safe, physicians should be aware of potential major complications.
 
Article
To evaluate the effects of Kinesio taping on a patient with chronic Achilles tendon pain. Case report. A 22-year-old male amateur badminton player slipped on the ground as he landed after jumping while playing badminton, resulting in chronic Achilles tendon pain of the dominant (right) leg. We performed Achilles tendon taping (ATT) over 5 weeks. The patient's ultrasonography showed that the tendon thickness was moderately reduced from 0.42 cm to 0.37 cm and that the angles of active dorsiflexion and active plantar flexion without pain increased from 15° to 20° and from 20° to 45°, respectively. The Victorian Institute of Sport Assessment-Achilles (VISA-A) questionnaire score increased from 64 to 95, and the load-induced pain assessment score decreased from 6 to 0. The pain threshold increased from 0.8 kg to 10 kg. The tenderness at 3 kg, assessed on a numeric rating scale, decreased from 7 to 0, and the patient was able to play badminton and soccer without pain. We verified the effect with an increase in the active ankle joint range of motion and the VISA-A questionnaire score, which was achieved by a decrease in tenderness and pain from repeated ATT application.
 
Position of measurement of Gastrocnemius MVC. 
Position of measurement of Soleus MVC. 
Muscle activity levels in experimental and control groups during HLECM exercise conditions. Data are mean and standard deviation. GAS SK ¼ gastrocnemius activity in straight knee condition. GAS BK ¼ gastrocnemius activity in bent knee condition. SOL SK ¼ soleus activity in straight knee condition. SOL BK ¼ soleus activity in bent knee condition. 
Article
To compare surface electromyographic (EMG) activity of the gastrocnemius and soleus muscles between persons with and without Achilles tendinopathy (AT) during an eccentric muscle exercise in different knee joint positions. Repeated measures design. Research laboratory. Participants (n = 18) diagnosed with AT and 18 control subjects were recruited. Gastrocnemius and soleus muscle activity was examined by surface (EMG) during extended and flexed knee joint conditions while performing the eccentric training technique. The EMG data were expressed as a percentage of a maximum voluntary contraction (MVC). EMG activity was notably higher (mean difference: 10%, effect size: 0.59) in those subjects with AT. Irrespective of the presence of AT, there was a significant interaction effect between muscle and joint position. The gastrocnemius muscle was significantly more active in the extended knee condition and soleus muscle activity was unchanged across joint positions. The results indicated that the presence of AT influenced calf muscle activity levels during performance of the eccentric exercise. There were differences in muscle activity during the extended and flexed knee conditions. This result does support performing Alfredson, Pietila, Jonsson, and Lorentzon (1998) eccentric exercise in an extended knee position but the specific effects of the knee flexed position on the Achilles tendon during eccentric exercise have yet to be determined, particularly in those with AT.
 
Article
Ruptures of the Achilles tendon are common however simultaneous ruptures occur less frequently. Eccentric loading exercise programmes have been used to successfully treat Achilles tendinopathy. We report a case of simultaneous bilateral Achilles tendon rupture in a patient predisposed to rupture due to longstanding raised serum lipoprotein and recently introduced therapeutic statin medication. The patient was also a keen rock climber and had regularly undertaken loading exercise. This case illustrates that the therapeutic effect of mixed loading exercises for the Achilles tendon may not be adequate to overcome the predisposition to rupture caused by hyperlipidaemia and statin medication.
 
Article
Objectives: Several substances are routinely injected in and around tendons. The present study evaluated the long term effects of high volume image guided injection (HVIGI) of normal saline, local anaesthetic and aprotinin in athletic patients with resistant tendinopathy of the main body of the Achilles tendon. Design: Case series. Methods: The study included a series of 94 athletes (69 men and 25 women; average age 37.5 years, range 22-63) with ultrasound confirmed tendinopathy of the main body of the Achilles tendon. All the patients had not improved after at least three months of conservative management. Patients were injected with 10 mL of 0.5% Bupivacaine Hydrochloride, 25 mg aprotinin, and up to 40 mL of injectable normal saline. We prospectively administered the Victorian Institute of Sport Assessment-Achilles tendon (VISA-A) to assess the short- and long-term pain and functional improvement. Results: At baseline (n = 94), the VISA-A score was 41.7 ± 23.2 (range 11-60), and had improved to 74.6 ± 21.4 (range 71-100) by 12 months (n = 87) (p = 0.003), with no significant difference between sexes. Conclusion: HVIGI with aprotinin significantly reduces pain and improves function in patients with chronic Achilles tendinopathy in the short- and long-term follow up.
 
Article
To determine the incidence and risk factors for injury associated with the performance of acrobatic gymnastics. Retrospective injury and training survey. New South Wales acrobatic gymnastics clubs. Surveys were completed by 73 acrobatic gymnasts (69 female) aged 8-26 years. Data on injury incidence and frequency for injury site were collected. Multiple-regression and ROC curve analysis were used to evaluate training-associated injury risk factors. Half (50.7%) of the participants had sustained an injury associated with acrobatic gymnastics in the past 12 months, with 28.8% of participants affected by chronic injury at the time of the study. Age of onset for acute and chronic acrobatics-related injury averaged 13.9 (SD +/- 3.03) and 14.7 (SD +/- 3.85) years, respectively. Injury sites were predominately the knee, ankle and wrist. Risk factors for injury were having an age of >or=13 years and training for >or=8 h per week at age 11 years. The results suggest that the 11-15 years age period is critical for the occurrence of injury in acrobatic gymnasts. This is possibly due to the adolescent growth spurt which may create an increased vulnerability to injury if training volume during this time is above a certain threshold.
 
Article
To compare electromyographic (EMG) activity of the serratus anterior (SA) during knee push-up plus exercises according to various surfaces (static stable, static unstable, and oscillating unstable surfaces). Comparative study by repeated measures. Yonsei University laboratory. In total, 15 healthy male subjects participated. The subjects performed knee push-up plus exercises on three different surfaces: static stable, static unstable, and oscillating unstable surfaces. Surface EMG activity of the SA for the peak and average amplitudes were collected from the dominant arm and presented as a percentage of the maximal voluntary contraction. A one-way repeated-measures ANOVA with a Bonferroni post hoc test was performed to compare differences in SA EMG activity according to the surface. The peak and average amplitudes of SA activity were significantly greater during knee push-up plus on the oscillating unstable surface than on the static stable or static unstable surfaces (p < 0.01). Additionally, there was no significant difference between the stable and static unstable surfaces (p > 0.05). Knee push-up plus exercise on an oscillating unstable surface activates the SA more than the same exercise on static stable and static unstable surfaces.
 
Article
Compare the muscle activation patterns of the quadricep-hamstring during drop jumps with increasing demands of drop heights. Observational. University biomechanics laboratory. Fifteen male and eight female college physical education students. Electromyographic activity of the rectus femoris (RF) and biceps femoris (BF) during the landing and takeoff phase of drop jumps from 20 to 60-cm heights. The ground contact time, vertical ground reaction force (vGRF), knee flexion angle during ground contact, and jump height after takeoff were also analyzed. The activation of RF was higher in the drop jump from 60-cm than that from 20- and 30-cm (comparing 107.0 ± 45.9 to 82.3 ± 30.8 and 88.9 ± 38.9 %MVIC, P<.05) during the landing phase. Activation of BF remained similar across all drop heights. Drop jump from 60-cm resulted in greater contact time during takeoff phase and peak vGRF, and resulted in greater maximum knee flexion but straighter knee at ground contact than from lower drop heights. At drop height of 60-cm, the altered knee muscular activation and movement patterns may diminish the effectiveness of plyometric training and increase the potential injury risk of knee.
 
Article
Objectives: Growing evidence supports hip muscle activation and strengthening exercise prescription to prevent and treat various lower limb injuries. Common prescriptions include single-legged and double-legged squatting, with and without a Swiss ball. We aimed to establish the effect of varying forms of squatting exercises on gluteal muscle activation. Design and setting: Observational laboratory study. Participants: Nineteen (11 male) healthy participants (28.4 +/- 2.7 years old) were compared using one-way repeated measures analysis of variance. Main outcome measures: Surface electromyography (EMG) measures of gluteus medius (GMed) and gluteus maximus (GMax) during the isometric phase of single-legged and double-legged squatting, with and without a Swiss ball. Results: A greater percentage of maximal voluntary contraction (%MVC) during single-legged squatting was found compared to double-legged squatting for GMed (42 versus 9%MVC, p < 0.001) and GMax (35 versus 14%MVC, p < 0.001). Additionally, the Swiss ball increased GMax activity (42 versus 35%MVC, p = 0.026) and demonstrated a trend toward increased GMed activity (46 versus 42%MVC, p = 0.075) during the single-legged squat. Conclusions: These results indicate single-legged squatting may be more appropriate than double-legged squatting to facilitate strength gains of GMed and GMax. Additionally, the Swiss ball may be a useful adjunct to target gluteal muscle strengthening during single-legged squatting.
 
Article
The trapezius muscle plays a crucial role in maintaining proper shoulder mechanics and is often considered a source of weakness and dysfunction in patients. The purpose of this study was to investigate the activation patterns of the middle and lower trapezius during four prone horizontal abduction exercises of the glenohumeral joint (GHJ). The muscle activation patterns of 19 female and 13 male volunteers were measured using surface EMG during horizontal arm abduction exercises commonly used in rehabilitative settings. Each subject performed 10 repetitions of horizontal abduction (ABD) at each position using only the weight of the arm. Function was assessed during shoulder horizontal abduction while positioned at: 75 degrees , 90 degrees , 125 degrees and 160 degrees of GHJ ABD. Electromyographic activity was collected during the concentric phase during each test repetition in the lower (LTRAP) and middle trapezius (MTRAP). A repeated measure ANOVA was performed followed by Bonferroni's post hoc test. The MTRAP had significantly greater recruitment at 90 degrees and 125 degrees , compared to 160 degrees . Similarly, results for the lower trapezius indicated that recruitment at 90 degrees and 125 degrees was significantly greater than 160 degrees . Most significant muscle activation for the middle and lower trapezius occurred at 90 degrees and 125 degrees of GHJ ABD. For the clinician, training at 90 degrees is easy to identify, and provides maximal activation, negating the need for multiple training angles.
 
Normalized aIEMG of the (a) VMO, (b) VL, and (c) VMO/VL ratio during concentric and eccentric phase of the leg press exercise up to 90 in 15 of knee flexion increment (n ¼ 10).  
Article
To investigate the effects of submaximal and vigorous isometric hip adduction on the vastus medialis obliquus (VMO) and vastus lateralis (VL) activity during the leg press exercise from 90° of knee flexion until full extension. Experimental. University biomechanics laboratory. Ten healthy male college students. Electromyographic (EMG) activation of VMO, VL and hip adductor longus (HAL) of the dominant leg were recorded during double leg press (LP), leg press with submaximal isometric hip adduction force (LP+), and leg press with vigorous isometric hip adduction force (LP++). The VMO, VL muscle activation, as well as the VMO/VL ratio between different leg press exercises were analyzed by MANOVA over concentric and eccentric phases, and in 15° increments of knee flexion motion. The effect size was calculated. Neither LP+ nor LP++ changed the overall VMO-VL activation patterns. Specific to knee angle, however, small to medium effect size was shown with incorporation of isometric hip adduction to the leg press exercise for VMO/VL ratio. Targeted training using the leg press exercise to the last 45° of knee extension/flexion with vigorous hip adduction may be useful in promoting a greater VMO/VL ratio.
 
Article
The purpose of this study was to establish reliability and responsiveness of the dynamic visual acuity test (DVAT) at head speeds of 150-200 degrees per second (deg/s) and the gaze stabilization test (GST) in high school and college football players. Reliability design. Fifty high school and college football athletes completed the DVAT and GST in both the yaw (horizontal) and pitch (vertical) planes twice within two weeks. Test-retest reliability for the DVAT was good in yaw, Intraclass Correlation Coefficient (ICC) = 0.770, and moderate/good in pitch, ICC = 0.725. Minimal detectable change (MDC) was 0.16 logMAR for yaw and 0.21 logMAR for pitch. GST reliability was moderate in yaw, ICC = 0.634, and poor in pitch, ICC = 0.411. MDCs were 73.4 deg/s (yaw) and 81.2 deg/s (pitch). The DVAT is reliable at high head speeds in high school and college football athletes in both yaw and pitch. GST head speeds were higher than previously reported in the literature, but reliability of this tool for this population was poor to moderate. From a clinical perspective, DVAT may be reliably used in the assessment of high school and college football athletes; however, GST requires further evaluation.
 
Article
To determine whether elite motorsport athletes demonstrate superior levels of Visual Acuity than age and sex-matched controls. A cross-sectional observational study. A University vision and balance laboratory. Young male motorsport athletes from the New Zealand Elite Motorsport Academy and healthy age and sex-matched controls. Vision performance tests comprising; Static Visual Acuity (SVA), Dynamic Visual Acuity (DVA), Gaze Stabilization Test (GST), and the Perception Time Test (PTT). Motorsport athletes demonstrated superior visual acuity compared to age and sex-matched controls for all measures, and while this was not statistically significant for SVA, GST and DVA, it reached statistical significance for the PTT (p<or=0.05). This preliminary investigation into the visual ability of motorsport athletes demonstrated that they may have superior visual performance when compared to controls. Increased visual acuity and perception time may not only act to increase performance, but may also reduce the risk of potential injury. This study highlights the need for further research into the area of visual performance, particularly in motorsport and other high-speed sports, where such skills might be integral to performance and injury reduction.
 
Article
Athletes suspected of being concussed are frequently evaluated on the side-line for self-reported symptoms which guide subsequent management and return-to-play decisions. Concussion-like symptoms have been shown to be influenced by prior participation in physical activity; however, the potential contribution of acute exercise on symptoms is not well understood. The purpose of this study was to systematically review the literature in order to further understand the acute effects of exercise on documented self-reported symptoms in both concussed and non-concussed individuals. Systematic narrative review. Nine electronic databases were systematically searched using keywords and MeSH terms that included; self-reported symptoms, sports-related concussion, brain concussion, exercise and athletic injuries. In addition, an extensive search of the grey literature was conducted. Of the 785 articles retrieved, only five met the inclusion criteria comprising a total of 295 concussed and non-concussed participants. In general, the mean symptom scores increased from pre-exercise to post-exercise levels immediately following acute bouts of exercise in both concussed and non-concussed individuals. Although the symptom scores increased following exercise in both concussed and non-concussed participants, this increase was only maintained for a relatively short duration. Thus, the application to real world situation is still to be established.
 
Article
To examine the effects of local cooling on mechanical properties of the quadriceps muscle in healthy subjects. Thirty-nine healthy subjects (27 women, 12 men, mean age 39, range 20-62) volunteered. A cold gel pack was applied to the quadriceps muscle for 20 min. Properties were quantified by analyzing the frequency (tension), decrement (elasticity) and stiffness of damped oscillations and the compliance of the muscle before, immediately after and after 15-min after cooling. The largest responses immediately after cooling were seen in the oscillation decrement parameter, 7.9 (3.7-12.1) %, and in the compliance parameter, -7.5 (-9.8 to -5.3) %. Responses in the oscillation frequency, 6.5 (2.3-10.6) %, and stiffness parameters, 4.0 (0.8-7.1) %, were also statistically significant. The compliance still showed a -6.1 (-7.7 to -4.5) % decrease after the 15 min recovery phase, while no remaining alteration was found in the oscillation parameters. The quadriceps muscle became tenser, stiffer, and less elastic as a result of cooling, and the mechanical properties were not fully recovered after 15 min. Careful warming-up is suggested after cooling to enable normalization of mechanical properties of the muscle and to avoid injuries.
 
Article
To investigate dynamic knee joint range of motion (ROM) and jump performance following a single bout of passive hamstring stretching, hamstring vibration or a combination of both. Knee joint dynamic ROM and jump performance were assessed prior to, immediately following and 10 min following stretching and vibration of the hamstring muscles. The study was a crossover design with all participants completing three interventions: (1) 3 x 30s static stretches of the hamstring muscles, (2) 3 x 30s bouts of vibration applied to the hamstring muscles, (3) a combination of the stretching and vibration protocols. The study was conducted in the muscle performance laboratory of Auckland University of Technology. Ten male participants (mean+/-SD, age 22.7+/-3.6 yr, height 181.2+/-6.51 cm, mass 84.9+/-12.3 kg) with no musculoskeletal problems volunteered to participate in this study. Dynamic knee joint ROM and jump height. The only increase in dynamic knee joint ROM was between the pre and immediate post assessments in the stretching intervention (mean change 3 degrees or 2%, ES=0.4, p=0.011). There was no statistically significant interaction between intervention and time for any of the jump performance assessments. A single bout of stretching produced a small, short-lived change in dynamic knee joint ROM but did not change jump performance. The addition of vibration alone or in combination with stretching did not influence dynamic knee joint ROM or jump performance.
 
Article
Acute hamstring injuries are the most prevalent muscle injuries reported in sport. Despite a thorough and concentrated effort to prevent and rehabilitate hamstring injuries, injury occurrence and re-injury rates have not improved over the past 28 years. This failure is most likely due to the following: 1) an over-reliance on treating the symptoms of injury, such as subjective measures of "pain", with drugs and interventions; 2) the risk factors investigated for hamstring injuries have not been related to the actual movements that cause hamstring injuries i.e. not functional; and, 3) a multi-factorial approach to assessment and treatment has not been utilized. The purpose of this clinical commentary is to introduce a model for progression through a return-to-sport rehabilitation following an acute hamstring injury. This model is developed from objective and quantifiable tests (i.e. clinical and functional tests) that are structured into a step-by-step algorithm. In addition, each step in the algorithm includes a treatment protocol. These protocols are meant to help the athlete to improve through each phase safely so that they can achieve the desired goals and progress through the algorithm and back to their chosen sport. We hope that this algorithm can serve as a foundation for future evidence based research and aid in the development of new objective and quantifiable testing methods.
 
Article
The purpose of this systematic review was to assess whether electrical stimulation (ES), when used in conjunction with a standard treatment, can reduce levels of functional impairment, edema, and pain compared to a standard treatment alone, in patients following a lateral ankle sprain. We searched PubMed, CINAHL, SportDiscus, and Medline (OVID) databases through June 2014 using the terms "ankle sprain or ankle sprains or ligament injury or ligamentous injury," and "electric stimulation or electric stimulation or electrotherapy." Our search identified four randomized control trials, of which, neuromuscular ES and high-voltage pulsed stimulation were the only two ES modalities utilized. Effect sizes and 95% confidence intervals (CI) were estimated using Cohen's d for comparison between treatment groups. Three of four effect sizes for function had 95% CI that crossed zero. Twenty-four of the thirty-two effect sizes for edema had 95% CI that crossed zero. All effect sizes for pain had 95% CI that crossed zero. Therefore, the use of ES is not recommended as a means to improve function, reduce edema, or decrease pain in the treatment of acute lateral ankle sprains. Copyright © 2015 Elsevier Ltd. All rights reserved.
 
Article
To investigate the change in passive hamstring stiffness and knee joint range of motion (ROM) following a single bout of passive hamstring stretching with or without active movement post-stretch. A Kincom dynamometer was used to measure knee joint ROM and passive stiffness in nine participants. Each participant completed three conditions: (1) a baseline test of knee extension ROM and passive stiffness, 4×20 second static stretches of the hamstring muscles and repeat testing immediately post-stretch and at 5min intervals for 20min; (2) the same procedure with the addition of 90s of isotonic knee flexion and extension between tests over the 20min post-stretching period; (3) the control condition involving repeat tests only over 20min. Knee joint ROM increased by 4-5° post-stretch in both intervention conditions, relative to the control condition, but there was no clear evidence of the ROM increase lasting longer than 5min. Both intervention conditions showed a small decrease in passive stiffness post-stretch and it is likely this effect lasted for at least 20min. An isolated bout of stretching produced a small, short-lived change in ROM and stiffness. This has implications for the design of warm-up protocols.
 
Article
To assess activation of muscles of hip adduction using EMG and force analysis during standard clinical tests, and compare athletes with and without a prior history of groin pain. Controlled laboratory study. 21 male athletes from an elite junior soccer program. Bilateral surface EMG recordings of the adductor magnus, adductor longus, gracilis and pectineus as well as a unilateral fine-wire EMG of the pectineus were made during isometric holds in six clinical examination tests. A load cell was used to measure force data. Test type was a significant factor in the EMG output for all four muscles (all muscles p < 0.01). EMG activation was highest in Hips 0 or Hips 45 for adductor magnus, adductor longus and gracilis. EMG activation for pectineus was highest in Hips 90. Injury history was a significant factor in the EMG output for the adductor longus (p < 0.05), pectineus (p < 0.01) and gracilis (p < 0.01) but not adductor magnus. For force data, clinical test type was a significant factor (p < 0.01) with Hips 0 being significantly stronger than Hips 45, Hips 90 and Side lay. BMI (body mass index) was a significant factor (p < 0.01) for producing a higher force. All other factors had no significant effect on the force outputs. Hip adduction strength assessment is best measured at hips 0 (which produced most force) or 45° flexion (which generally gave the highest EMG output). Muscle EMG varied significantly with clinical test position. Athletes with previous groin injury had a significant fall in some EMG outputs.
 
Article
To evaluate short and mid-term results of active physical therapy in athletes with longstanding groin pain. Case series. Primary care physical therapy practice. A total of 44 athletes suffering longstanding adductor-related groin pain. A combination of passive (joint mobilization) and active (exercises) physical therapy interventions. Return to (the same level of) sports, restriction in sports, and recurrence. Directly after treatment, return to the same level and type of sport was successful in 38 athletes (86%), and without symptoms in 34 athletes (77%). At 6.5-51 months follow up, 10/38 (26%) of those that returned to sports had experienced a relapse; 22 (50%) athletes were able to participate in sports without any restrictions at the mid-term follow-up. For athletes with longstanding groin pain, short term results of physical therapy seem positive, whereas mid-term results are moderately positive. The risk for recurrence is high.
 
Article
To determine the relationship between the amount of humeral torsion and a measure of active proprioception in adolescent male throwing athletes. Cross-sectional laboratory study with uninjured subjects. University of Sydney and NSW Institute of Sport. Participants were 16 adolescent male baseball players (15.0-18.1 years old, SD=16.3) holding baseball scholarships at the NSW Institute of Sport. The main outcome measures, active proprioception (shoulder rotation, in 90 degrees of arm abduction moving towards external rotation, using the Active Movement Extent Discriminating Apparatus) and humeral torsion (using an ultrasound-assisted method), were measured bilaterally. A strong (r=0.88) and significant (p=0.001) correlation was found between increasing humeral retrotorsion and better active proprioceptive acuity in the non-dominant arm, while the relation was weaker (r=0.41) and did not reach statistical significance (p=0.120) for the dominant arm. A cognitive processing capacity model, which suggests that greater humeral retrotorsion reduces neural processing requirements, has been proposed to explain the direct relationship between proprioceptive acuity and humeral retrotorsion.
 
Article
Objectives: To evaluate the reliability level of an innovative method using a standardized stretch force to assess the flexibility of lower limb muscle groups in highly-trained adolescent athletes and to examine whether interchanging the examiners affects the reliability of the measures. Design: Randomized test-retest study. Setting and participants: In ten athletes, the flexibility of eight lower limb muscle groups was examined on two occasions on both sides and in two phases: a video capture by three distinct operators and an analysis by three distinct analysers. The reliability of the measures was assessed by the coefficient of variation (CV, 90% CI). Between-analysers and between-operators standardized differences (i.e., Cohen's d) were calculated. Results: CV (%, 90% CI) were 8.3% (7.5; 9.3) for quadriceps, 3.3% (3.0; 3.7) for hamstrings, 7.2% (6.5-8.0) for adductors, 5.7% (5.1; 6.3) for gastrocnemius, 4.5% (4.0; 5.0) for soleus, 2.6% (2.3; 2.9) for hip flexors, 9.6% (8.6; 10.8) for hip medial rotators and 12.4% (12.2; 14.0) for hip lateral rotators. There was no substantial (i.e., Cohen's d < 0.2) difference in CV between all the possible operators/analysers combinations. Conclusion: This method has a moderate-to-good reliability level and is examiner-independent. It may be implemented in future injury prevention programs, in order to monitor the flexibility of highly-trained adolescent athletes.
 
Pre-stretching exercises. 
Passive straight leg raise test. 
A BlandeAltman plot. The differences between the SRT and TT tests are plotted against each individual's mean for the 2 tests to show the presence of heteroscedasticity. The bias line and random error lines forming the 95% limits of agreement are also presented on the plot. Visual inspection of the data suggested that the differences were not greater with the highest maximal mean scores (r ¼ 0.013; p ¼ 0.848).
Kappa correlations.
Article
1) to examine the test-retest reproducibility and criterion-related validity of the sit and reach test (SRT) and the toe touch test (TT) for estimating hamstring flexibility measured through the passive straight leg raise test (PSLR); and 2) to determine whether the SRT cut-off scores may be used for the TT test to identify participants in this sample of young healthy adults as having short hamstring flexibility. Test-retest design. Controlled laboratory environment. 243 active recreationally young adults. Participants performed the SRT, the TT test and PSLR twice in a randomized order with a 4-week interval between trials. Reproducibility was examined using typical percentage error (coefficient of variation [CV]) and intraclass correlation coefficient (ICC) as well as their respective confidence limits. Regression and Kappa correlation statistical analyses were performed to study the association of the SRT and TT test with the PSLR test and the 95% limits of agreement (LoA) between SRT and TT test were calculated to explore differences in the mean differences between these measurements. The finding showed acceptable reproducibility measures for SRT (8.74% CV; 0.92 ICC), TT test (9.86% CV; 0.89 ICC) and PSLR (5.46% CV; 0.85 ICC). The SRT (R(2) = 0.63) and TT test (R(2) = 0.49) were significantly associated with PSLR. The 95% LoA between SRT and TT test reported systematic bias (2.84 cm) and wide 95% random error (±9.72 cm). Reproducibility of SRT, TT test and PSLR is acceptable and the criterion-related validity of SRT and TT test is moderate. Furthermore, the SRT cut-off scores should not be used for TT test for the detection of short hamstring muscles.
 
Article
To assess the reproducibility of isokinetic eccentric and concentric knee extension and flexion strength indices obtained at two different angular velocities. Cohort study. University human performance laboratory. 45 healthy physically active young adults (25 males). A non reciprocal protocol of concentric and eccentric contractions of the knee extensors and flexors was performed at 30 and 120°/s. Strength indices evaluated included peak moment; dynamic control ratios; and the difference between eccentric and concentric ratio at the two angular velocities. No evidence for inter-test bias in any of the strength indices was noted. Measurement precision for peak moment, as quantified using ratio limits of agreement, suggest that scores may be expected to vary up to 15% for the knee extensors in both eccentric and concentric contraction modes. An error of up to 19% was calculated for the peak moment scores of the knee flexors. Intraclass correlation coefficients revealed fairly robust preservation of participants' rank order for the majority of strength indices (>0.85). Isokinetic-related indices of knee muscles performance enable an acceptable level of detection of expected changes in muscular strength parameters as a result of planned interventions.
 
Article
The following is a critical description and discussion of the successful assessment and rehabilitation of a right shoulder posterior Bankart repair in an elite rugby league player. The rehabilitation follows accelerated, goal based guidelines, widely adopted in current sports practice but not well documented in the literature (Funk & Snow, 2007; Park, Lin, Yokota, & McFarland, 2004). The study serves to be the first critical discussion of such a regime.
 
Summary of included studies. 
Results for the kinetic and kinematic variables of the knee and hip. 
Article
The aim of this literature review was to identify the biomechanical variables involved in the aetiology of iliotibial band syndrome (ITBS) in distance runners. An electronic search was conducted using the terms "iliotibial band" and "iliotibial tract". The results showed that runners with a history of ITBS appear to display decreased rear foot eversion, tibial internal rotation and hip adduction angles at heel strike while having greater maximum internal rotation angles at the knee and decreased total abduction and adduction range of motion at the hip during stance phase. They further appear to experience greater invertor moments at their feet, decreased abduction and flexion velocities at their hips and to reach maximum hip flexion angles earlier than healthy controls. Maximum normalised braking forces seem to be decreased in these athletes. The literature is inconclusive with regards to muscle strength deficits in runners with a history of ITBS. Prospective research suggested that greater internal rotation at the knee joint and increased adduction angles of the hip may play a role in the aetiology of ITBS and that the strain rate in the iliotibial bands of these runners may be increased compared to healthy controls. A clear biomechanical cause for ITBS could not be devised due to the lack of prospective research.
 
Article
1. To determine whether individuals with chronic ankle instability (CAI) have lower proprioception sensitivity scores from a test on the Active Movement Extent Discrimination Apparatus (AMEDA). 2. To determine whether individuals with CAI can improve proprioception sensitivity scores with repeated active movement testing using the AMEDA. 3. To assess the test-retest reliability of the AMEDA. A cohort study comparing those with CAI or healthy ankles. University clinical laboratory. 61 healthy university students, 36 with CAI, 25 with stable ankles. A 2-way ANOVA was conducted to compare performance of CAI and stable ankle groups, over 3 test repetitions on the AMEDA. The reliability intra-class correlation coefficient (ICC) was obtained for test repetitions. The scores improved in both groups when the AMEDA test was repeated (p = <0.001). The rates of improvement in proprioception test scores differed, with the CAI group showing a slower learning rate than the stable ankle group (p = 0.047). The ICC for the whole group across the three trials was 0.80 (95% CI = 0.69 to 0.87, p = <0.001). CAI participants improve their proprioception scores more slowly upon repeated AMEDA testing, suggesting differences in learning strategies.
 
Article
To investigate physiotherapist agreement in rating movement quality during lower extremity functional tests using two visual rating methods and physiotherapists with differing clinical experience. Clinical measurement. Six healthy individuals were rated by 44 physiotherapists. These raters were in three groups (inexperienced, novice, experienced). Video recordings of all six individuals performing four lower extremity functional tests were visually rated (dichotomous or ordinal scale) using two rating methods (overall or segment) on two occasions separated by 3-4 weeks. Intra and inter-rater agreement for physiotherapists was determined using overall percentage agreement (OPA) and the first order agreement coefficient (AC1). Intra-rater agreement for overall and segment methods ranged from slight to almost perfect (OPA: 29-96%, AC1: 0.01 to 0.96). AC1 agreement was better in the experienced group (84-99% likelihood) and for dichotomous rating (97-100% likelihood). Inter-rater agreement ranged from fair to good (OPA: 45-79%; AC1: 0.22-0.71). AC1 agreement was not influenced by clinical experience but was again better using dichotomous rating. Physiotherapists' visual rating of movement quality during lower extremity functional tests resulted in slight to almost perfect intra-rater agreement and fair to good inter-rater agreement. Agreement improved with increased level of clinical experience and use of dichotomous rating.
 
Top-cited authors
John Cronin
  • Auckland University of Technology
Kim Bennell
  • University of Melbourne
Keith George
  • Liverpool John Moores University
Peter Maulder
  • Waikato Institute of Technology
Roger Adams
  • The University of Sydney