Physical Therapy in Sport - Articles in Press

Comparison of electromyographic activity of the lower trapezius and serratus anterior muscle in different arm-lifting scapular posterior tilt exercises - Corrected Proof

2012-01-30

Abstract: Objective: To determine the most effective exercise to specifically activate the scapular posterior tilting muscles by comparing muscle activity generated by different exercises (wall facing arm lift, prone arm lift, backward rocking arm lift, backward rocking diagonal arm lift).Design: Repeated-measure within-subject intervention.Participants: The subjects were 20 healthy young men and women.Main outcome measures: Lower trapezius (LT) and serratus anterior (SA) muscle activity was measured when subjects performed the four exercises.Results: Muscle activity was significantly different among the four exercise positions (p<0.05). The backward rocking diagonal arm lift elicited significantly greater activity in the LT muscle than did the other exercises (p<0.05). The backward rocking arm lift showed significantly more activity in the SA muscle than did the other exercises (p<0.05).Conclusions: Clinicians can use these results to develop scapular posterior tilting exercises that specifically activate the target muscle.

Reproducibility and criterion-related validity of the sit and reach test and toe touch test for estimating hamstring flexibility in recreationally active young adults - Corrected Proof

F. Ayala, P. Sainz de Baranda, M. De Ste Croix, F. Santonja — 2012-01-24

Abstract: Objective: 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.Design: Test-retest design.Setting: Controlled laboratory environment.Participants: 243 active recreationally young adults.Main outcome measures: 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.Results: 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 (R2 = 0.63) and TT test (R2 = 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).Conclusions: 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.

The effect of foot orthotic use on exercise related leg pain in cross country athletes - Corrected Proof

Mark F. Reinking, Ann M. Hayes, Tricia M. Austin — 2012-01-16

Abstract: Objectives: The purposes of this research were to (1) investigate the effect of foot orthotic use on exercise related leg pain (ERLP) in cross-country (XC) athletes, and (2) determine if an association between foot type and foot orthotic use exists.Design: Prospective cohort design.Setting: High schools and colleges in a Midwestern metropolitan region.Participants: 213 high school and college XC athletes (107 male, 106 female).Materials/Methods: Participants were seen before the fall XC season for classification of foot type, visual orthotic inspection, and questionnaire completion regarding foot orthotic use and ERLP. Statistical analysis of relationships (chi-square) was conducted.Results: 37 of the 213 XC athletes (17.4%) used foot orthotics; 31 of the 37 athletes using foot orthotics (83.8%) reported a history of ERLP. Of these 31 athletes, 17 (54.8%) were using orthotics for ERLP and 15 reported a decrease in ERLP with orthotic use. Fourteen athletes were using orthotics for a reason other than ERLP and only 2 reported a decrease in ERLP with orthotic use. Athletes using orthotics included all three foot types (pronated, neutral, supinated) with no relationship between orthotic use and foot type.Conclusion: One-sixth of the XC athletes used foot orthotics and most using orthotics for ERLP reported a decrease in ERLP symptoms. The majority of athletes using orthotics for reasons other than ERLP reported no change in ERLP symptoms. There was no association between foot type and orthotic use.

The effect of heat applied with stretch to increase range of motion: A systematic review - Corrected Proof

Jiro Nakano, Cristiane Yamabayashi, Alex Scott, W. Darlene Reid — 2011-12-30

Abstract: Application of heat to muscle is commonly advocated to enhance the efficacy of stretching. However, the effect of this combined therapy using different methods of heating, applied to different muscles, and after one or multiple treatments, is not known.To perform a systematic review to address the question: Does stretching augmented by heat application result in greater gains in range of motion (ROM) compared to stretch alone?The following databases were searched for original articles that evaluated our question: MEDLINE, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials, SPORTDiscus and PEDro databases. After title and abstract screening followed by full-text screening, the quality of included articles was assessed and their data was abstracted. Screening, data abstraction and quality assessment was performed and consensus was achieved by two reviewers. Range of motion (ROM) data were synthesized by meta-analyses for overall effect and subgroup analysis according to muscle group, method of heat application, single or multiple treatments, and reported tightness of muscle. Twelve studies were included and reported the effects of stretch with or without heat on ROM of 352 participants. Heat applications included ultrasound, shortwave diathermy and hot packs. Meta-analyses and subgroup analyses demonstrated greater increases in ROM after heat and stretch (H + S) than heat alone. Subgroup analysis of muscle groups and the method of heat application showed some trends, but no significant differences. Multiple treatments (more so than single treatments) showed consistent treatment effects of H + S versus stretch alone amongst subgroups. Muscles described as tight did not show a greater treatment effect in response to H + S compared to muscles not reported as tight.Heating provides an added benefit on stretch related gains of ROM in healthy people.

A neuroscience approach to managing athletes with low back pain - Corrected Proof

Emilio J. Puentedura, Adriaan Louw — 2011-12-29

Abstract: Low back pain (LBP) is a common complaint within the athletic population and is commonly managed through a biomedical approach. The injured or damaged structure causing the LBP is identified and treated, and complete recovery from the episode is expected. Clinical experience shows us that often, athletes with LBP will not recover from their episode and may continue their sports participation despite persistent pain, or they may limit participation. Recent neuroscience research into the biology of pain suggests that clinicians involved in the management of athletes with LBP should embrace a biopsychosocial approach by engaging the brain and nervous system. This manuscript provides an overview of such a biopsychosocial approach, and presents information on the neurobiology of the athlete's pain experience.

The understanding of the concept of ‘rest’ in the management of a sports concussion by physical therapy students: A descriptive study - Corrected Proof

2011-12-21

Abstract: Objectives: To investigate physical therapy students’ understanding of the concept of rest following a sport concussion and to ascertain if this understanding changes following a lecture based on current best practice concussion knowledge.Design: Pre-post observational survey.Setting: University classroom setting.Participants: A cohort of 118 (40 male, 78 female) physical therapy students participating in volunteer sports medic training.Results: Participants provided 320 (pre) and 350 (post) responses depicting activities which should be restricted following a concussion. The responses were classified into three rest-related categories: ‘Physical rest’, ‘Cognitive rest’ and ‘Mixed’ (a combination of physical and cognitive rest). Pre-lecture, approximately 74% of the student’s responses were categorized as Physical rest, and 25% under Mixed. There was a shift in the response pattern post-lecture, with 96% of the responses falling in the Mixed category.Conclusions: The results of the study highlight a lack of understanding of the concept of cognitive rest in concussion management among trainee sport medics. The need for wider dissemination of this concept as recommended by the recent consensus statement on sports concussion is indicated.

Application of posterior pelvic tilt taping for the treatment of chronic low back pain with sacroiliac joint dysfunction and increased sacral horizontal angle - Corrected Proof

Jung-hoon Lee, Won-gyu Yoo — 2011-12-09

Abstract: Objective: Kinesio Taping (KT) is a therapeutic method used by physical therapists and athletic trainers in combination with other treatment techniques for various musculoskeletal and neuromuscular problems. However, no research has evaluated the effect of KT in patients with low back pain (LBP). The purpose of this case was to describe the application of posterior pelvic tilt taping (PPTT) with Kinesio tape as a treatment for chronic LBP and to reduce the anterior pelvic tilt angle.Design: Case report.Case description: The patien was a 20-year-old female amateur swimmer with a Cobb’s angle (L1–S1) of 68°, a sacral horizontal angle of 45°, and pain in both medial buttock areas and sacroiliac joints. We performed PPTT with Kinesio tape for 2 weeks (six times per week for an average of 9h each time).Results: The patient’s radiographs showed that the Cobb’s angle (L1–S1) had decreased from 68° to 47° and that the sacral horizontal angle had decreased from 45° to 31°. Reductions in hypomobility or motion asymmetry, as assessed by the motion palpation test, and in pain, as measured by the pain-provocation tests, were observed. On palpation for both medial buttock areas in the prone position, the patient felt no pain. The patient experienced no pain or stiffness in the low back area while performing forward flexion in the standing position with knees fully extended when washing dishes in the sink.Conclusions: The case study demonstrated that PPTT intervention favourably affected the pelvic inclination and sacral horizontal angle, leading to beneficial effects on sacroiliac joint dysfunction (SIJD) and medial buttock pain. Additional research on the clinical effects of this taping procedure requires greater numbers of athletes with SIJD or LBP who have inappropriate anterior pelvic tilt angles and hyperlordosis.

Asymmetry of the ULNT1 elbow extension range-of-motion in a healthy population: Consequences for clinical practice and research - Corrected Proof

2011-10-28

Abstract: Objectives: To investigate the effect of isolated muscular variance, side and hand dominance on elbow-extension range-of-motion (EE-ROM) of the median nerve upper limb neurodynamic test (ULNT1). This study analyzes these variables potential to influence ULNT1 EE-ROM symmetry and the possible consequences for clinical practice and research.Study design: Controlled laboratory study, cross-sectional.Background: No normative data exist to interpret correctly EE-ROM. Clinical interpretation is based on bilateral comparison. This procedure assumes natural EE-ROM symmetry, with lack of scientific evidence.Methods: Nineteen participants with Langer’s axillary arch (LAA), a muscular variant bridging the brachial plexus, were selected from 640 healthy volunteers, together with a matched control group. ULNT1 EE-ROM’s were measured using the Vicon® optoelectronic system.Results: A full mixed model revealed no significant effects on EE-ROM for LAA and the variable side. Significant differences were found in EE-ROM between dominant and non-dominant sides (standard ULNT1 test position: 2.84° ± 1.60°, p = 0.0004; ULNT1 with differentiating maneuver: 3.05° ± 1.98°, p = 0.003). Approximately 30% of the subjects showed clinically detectable restriction (≥10°) of the dominant side EE-ROM.Conclusion: Hand dominance is significantly associated with restriction of EE-ROM, which results in a clinically detectable asymmetry. This compromises the clinical procedure of comparing the patient’s EE-ROM to the opposite side. Erroneous conclusions could result in side to side analyses, if the effect is not taken into account in neurodynamic research.

Reproducibility of isokinetic knee eccentric and concentric strength indices in asymptomatic young adults - Corrected Proof

2011-10-24

Abstract: Objective: To assess the reproducibility of isokinetic eccentric and concentric knee extension and flexion strength indices obtained at two different angular velocities.Design: Cohort study.Setting: University human performance laboratory.Participants: 45 healthy physically active young adults (25 males).Main outcome measures: 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.Results: 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).Conclusion: 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.

EMG of the hip adductor muscles in six clinical examination tests - Corrected Proof

Gregory A. Lovell, Peter D. Blanch, Christopher J. Barnes — 2011-10-05

Abstract: Objectives: 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.Study design: Controlled laboratory study.Participants: 21 male athletes from an elite junior soccer program.Main outcome measures: 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.Results: 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.Conclusions: 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.

Running injuries and associated factors in participants of ING Taipei Marathon - Corrected Proof

Wei-Ling Chang, Yi-Fen Shih, Wen-Yin Chen — 2011-09-21

Abstract: Objectives: To investigate the distribution of lower extremity running injuries and their associated factors.Design: Descriptive and exploratory study.Participants: 1004 participants of the 2005 ING Taipei International Marathon.Main outcome measures: We used a self-developed questionnaire to collect data of previous running injuries and applied multivariate logistic regression modeling to examine relationships between these injuries and associated factors.Results: Of the 893 valid questionnaires, 396 (44.4%) reported having previous lower extremity pain related to running. Knee joint pain was the most common problem (32.5%). Hip pain was associated with the racing group, training duration, and medial arch support. Use of knee orthotics (P = 0.002) and ankle braces (P = 0.007) was related to a higher rate of knee and ankle pain. Participants of the full marathon group who practiced on a synthetic track had a higher incidence of ankle pain. A training duration of >60 min was linked to an increased rate of foot pain (P = 0.003).Conclusion: Our data indicated that running injuries were associated with training duration and use of orthotics. Clinicians can use this information in treating or preventing running associated injuries and pain.

Treatment of chronic Achilles tendon pain by Kinesio taping in an amateur badminton player - Corrected Proof

Jung-hoon Lee, Won-gyu Yoo — 2011-09-19

Abstract: Objective: To evaluate the effects of Kinesio taping on a patient with chronic Achilles tendon pain.Design: Case report.Case description: 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.Results: 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.Conclusions: 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.

Postural stability decreases in elite young soccer players after a competitive soccer match - Corrected Proof

2011-09-19

Abstract: Objective: To investigate the effects of an official soccer match on postural stability in youth elite soccer players.Design: Single-group pre-post design.Setting: Competitive soccer match.Participants: Twenty elite U-19 male soccer players (mean age: 17.7 ± 1.0 years) of which 11 completed the full experimental set-up.Main outcome measures: Postural stability evaluated by unilateral stance tests for dominant and non-dominant lower limbs on a force plate under two visual conditions: eyes opened (EO) and eyes closed (EC).Results: After the match, the centre of gravity (CoG) sway velocity with EO increased on the dominant and non-dominant limbs (median [interquartile range], 0.90°/s [0.60–1.10] vs. 1.10°/s [0.60–1.60]; and 0.70°/s [0.50–0.90] vs 1.00°/s [0.70–1.30]; respectively; p < 0.05). The CoG sway velocity with eyes closed did not change pre- to post-match.Conclusions: The soccer match decreased the postural stability only when the assessment was conducted with eyes open.

Achilles tendon tear following shock wave therapy for calcific tendinopathy of the Achilles tendon: A case report - Corrected Proof

Tsung-Ching Lin, Cheng-Yuan Lin, Cheng-Liang Chou, Cheng-Ming Chiu — 2011-09-19

Abstract: Introduction: 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.Case report: 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.Conclusion: While ESWT is generally considered safe, physicians should be aware of potential major complications.

Electromyographic analysis of an eccentric calf muscle exercise in persons with and without Achilles tendinopathy - Corrected Proof

2011-09-19

Abstract: Objectives: 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.Design: Repeated measures design.Setting: Research laboratory.Participants: Participants (n = 18) diagnosed with AT and 18 control subjects were recruited.Main outcome measures: 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).Results: 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.Conclusions: 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 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.

Evidence of the physiotherapeutic interventions used currently after exercise-induced muscle damage: Systematic review and meta-analysis - Corrected Proof

Rui Torres, Fernando Ribeiro, José Alberto Duarte, Jan MH Cabri — 2011-09-15

Abstract: Introduction: Exhaustive and/or unaccustomed exercise, mainly involving eccentric muscle actions, induces temporary muscle damage, evidenced by delayed onset muscle soreness (DOMS) and decreased muscle function. Different strategies to recover from its signs and symptoms have been studied and, as a result, a significant number of articles on this issue have been published.Objective: To assess whether some modalities currently used in physiotherapy such as massage, cryotherapy, stretching and low-intensity exercise are effective for treating the signs and symptoms of exercise-induced muscle damage.Methods: Randomized controlled trials (RCTs), written in English or Portuguese, that included physiotherapeutic interventions [i.e., massage, cryotherapy, stretching and low-intensity exercise, on adult human subjects (18–60 years old) of both gender] were searched on electronic databases including MEDLINE, CINHAL, EMBASE, PEDro and SPORTDiscus.Main outcome measures: “Muscle soreness” and “muscle strength” were the outcome measures included in the meta-analysis.Results: Thirty-five studies were included; nine analysed the effects of massage, 10 examined the effects of cryotherapy, nine investigated the effects of stretching and seven focused on low-intensity exercise intervention.Massage was the only intervention with positive effects, reducing soreness at 24 h, on average, 0.33 on 10 cm visual analog scale (95 percent CI: −0.59, −0.07) and increasing muscle recovery by 1.87 percent (95 percent CI: 0.30, 3.44). Additionally, there is inconclusive evidence to support the use of cryotherapy, while there is little evidence to prove the efficacy of stretching and low-intensity exercise.Conclusion: Massage proved slightly effective in the relief of symptoms and signs of exercise-induced muscle damage. Therefore, its mean effect was too small to be of clinical relevance. There is a lack of evidence to support the use of cryotherapy, stretching and low-intensity exercise.

An examination, correlation, and comparison of static and dynamic measures of postural stability in healthy, physically active adult - Corrected Proof

Timothy C. Sell — 2011-08-29

Abstract: Objective: To examine the relationship and differences between static and dynamic postural stability in healthy, physically active adults.Design: Descriptive laboratory study.Setting: Research laboratory.Participants: 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).Main outcome measures: 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).Results: 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.Conclusions: 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.

Physiotherapist agreement when visually rating movement quality during lower extremity functional screening tests - Corrected Proof

Chris Whatman, Wayne Hing, Patria Hume — 2011-08-29

Abstract: Objectives: To investigate physiotherapist agreement in rating movement quality during lower extremity functional tests using two visual rating methods and physiotherapists with differing clinical experience.Design: Clinical measurement.Participants: Six healthy individuals were rated by 44 physiotherapists. These raters were in three groups (inexperienced, novice, experienced).Main measures: 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).Results: 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.Conclusions: 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.

Taekwondo training improves the neuromotor excitability and reaction of large and small muscles - Corrected Proof

Polly Chung, Gabriel Ng — 2011-08-29

Abstract: Objectives: This study measured the neuromotor excitability and reaction time in professional and amateur Taekwondo (TKD) practitioners and compared them with non-athletes.Design: A cross-sectional cohort study design.Setting: Exercise laboratory setting.Participants: 40 TKD practitioners (20 professionals, 20 amateurs) and 20 non-athletes.Main outcome measures: Neuromotor excitability (rheobase), premotor reaction time (PRT), total reaction time (TRT) and electromechanical delay (EMD) of rectus femoris (RF) and flexor pollicis brevis (FPB) in response to audio and visual stimuli were measured. The professional TKD practitioners have shorter TRT than non-athletes with sport-specific visual stimuli but they have longer PRT and TRT in response to audio stimuli than the amateur practitioners and non-athletes.Results: The professional practitioners have longer EMD than the amateurs in responding to audio (p = 0.032) and sports-specific visual stimuli (p = 0.03) in FPB. Professional practitioners have higher excitability in RF (p < 0.001) than the amateurs and non-athletes.Conclusion: We conclude that professional TKD practitioners have better neuromotor ability in both large and small muscles with faster reactions to sport-specific stimuli, suggesting a generalized training effect across muscles. They react slower to non-sport specific stimuli, which suggested a decreased sensitivity to irrelevant sensory inputs after intensive TKD training.

Elbow isokinetic strength characteristics among collegiate baseball players - Corrected Proof

Kevin G. Laudner, James T. Wilson, Keith Meister — 2011-08-25

Abstract: Objectives: To compare the bilateral strength characteristics of the wrist flexors, extensors, pronators, and supinators among baseball players.Design: Cross-sectional.Setting: Laboratory.Participants: 30 collegiate baseball players with no recent history of upper extremity injury.Main outcome measures: Bilateral pronation, supination, wrist flexion, and wrist extension peak torque (PT) and peak torque to body weight (PT/BW) strength were measured at speeds of 90 and 180°/second.Results: Paired t-tests showed that the throwing arm of baseball players produced significantly less PT/BW strength for supination at 90°/second compared to the non-throwing arm (P = .001). The throwing arm produced significantly more PT/BW strength for pronation (P = .001) at 180°/second compared to the non-throwing arm. Furthermore, the throwing arm had more PT and PT/BW strength for wrist extension (P < .005) at 180°/second. Conversely, the throwing arm had less PT and PT/BW strength for supination (P < .004) and wrist flexion (P < .004) at 180°/second compared to the non-throwing arm.Conclusions: Significant bilateral strength differences exist in pronation, supination, wrist flexion, and wrist extension among collegiate baseball players.With the steady increase in ulnar collateral ligament injuries of the elbow among baseball players and the proven resistance to valgus force provided by the flexor-pronator mass of the elbow, the results of this study may prove beneficial in the prevention, evaluation, and rehabilitation of such dysfunctions.

Time to peak force is related to frontal plane landing kinematics in female athletes - Corrected Proof

Christopher R. Carcia, Benjamin R. Kivlan, Jason S. Scibek — 2011-07-25

Abstract: Objectives: Determine the relationship between unilateral lower extremity closed kinetic chain muscle performance and unilateral frontal plane landing kinematics.Design: Descriptive.Setting: Outpatient physical therapy clinic.Participants: Twenty adolescent female athletes.Main outcome measures: Unilateral lower extremity muscle performance was quantified at 25° of knee flexion on a computerized leg press. Unilateral frontal plane tibiofemoral kinematics were captured with a bi-axial electrogoniometer during a drop jump maneuver from a 40 cm platform.Results: Peak and average force and force normalized to body weight were not significantly related to frontal plane landing kinematics. Time to peak force however was related to both frontal plane initial contact (r = −0.54; P = 0.013) and peak angles at 100 ms post-contact (r = −0.53; P = 0.016). As time to peak force increased, tibiofemoral angles were in greater amounts of valgus.Conclusions: During an isometric closed kinetic chain unilateral squat test at 25 degrees of knee flexion, the time to peak force is related to frontal plane landing kinematics. Females who take longer to generate peak force are more likely to exhibit valgus kinematic patterns during the landing task. However, strength measures (peak force, average force or peak and average force normalized to body weight) are not associated with unilateral landing kinematics in female athletes.

Trunk muscle activity during spine stabilization exercises performed in a pool - Corrected Proof

Eadric Bressel, Dennis G. Dolny, Coby Vandenberg, John B. Cronin — 2011-07-11

Abstract: Objectives: To compare trunk muscle activity levels among a variety of therapeutic aquatic exercises designed for patients with low back pain.Study design: Quantitative observational laboratory study.Setting: Sports medicine clinic housed in a University.Participants: Eleven physically active males aged 25.7 ± 5.53 years.Main outcome measures: Surface electromyographic (EMG) data from muscles rectus abdominis (RA), external oblique (EO), lower abdominals (LA), multifidus (MT), and erector spinae (ES) were recorded and then normalized to a maximal voluntary contraction.Results: EMG values during abdominal bracing and Swiss ball exercises for muscles RA, EO, LA, and ES were significantly greater than most other exercises tested that included pelvic tilt, marching, hip abduction, and alternating arm exercises (P = .04–.001). EMG values of muscle LA were also greater for the abdominal hollowing exercise, whereas muscle MT displayed the greatest EMG values during the hip abduction exercise when compared to most other exercises tested (P = .02–.001).Conclusions: The aquatic exercises that maximize trunk muscle activity in the healthy males studied are abdominal bracing and Swiss ball exercises. Some muscles were selectively activated during abdominal hollowing (LA) and hip abduction (MT) exercises when compared to most other exercises.