Purpose:

To determine if heel height alters vertical ground reaction forces (vGRF) when landing from a forward hop or drop landing.

Background:

Increased vGRF during landing are theorized to increase ACL injury risk in female athletes.

Methods:

Fifty collegiate females performed two single‐limb landing tasks while wearing heel lifts of three different sizes (0, 12 & 24 mm) attached to the bottom of a athletic shoe. Using a force plate, peak vGRF at landing was examined. Repeated measures ANOVAs were used to determine the influence of heel height on the dependent measures.

Results:

Forward hop task‐ Peak vGRF (normalized for body mass) with 0 mm, 12 mm, and 24 mm lifts were 2.613±0.498, 2.616±0.497 and 2.495±0.518% BW, respectively. Significant differences were noted between 0 and 24 mm lift (p<.001) and 12 and 24 mm lifts (p=.004), but not between the 0 and 12 mm conditions (p=.927). Jump‐landing task‐ No significant differences were found in peak vGRF (p=.192) between any of the heel lift conditions.

Conclusions:

The addition of a 24 mm heel lift to the bottom of a sneaker significantly alters peak vGRF upon landing from a unilateral forward hop but not from a jumping maneuver.

Purpose/Background:

Cryotherapy is commonly used in physical therapy with many known benefits; however several investigations have reported decreased functional performance following therapeutic application thereof. The purpose of this study was to determine the effect of cryotherapy applied to the ankle on static and dynamic standing balance. It was hypothesized that balance would be decreased after cryotherapy application.

Methods:

Twenty individuals (aged 18 to 40 years) participated in this research project. Each participant was tested under two conditions: an experimental condition where subjects received ice water immersion of the foot and ankle for 15 minutes immediately before balance testing and a control condition completed at room temperature. A Biodex® Balance System was used to quantify balance using anterior/posterior (AP), medial/lateral (ML), and overall balance indices. Paired t‐tests were used to compare the balance indices for the two conditions with alpha set at 0.05 a priori. Effect size was also calculated to account for the multiple comparisons made.

Results:

The static balance indices did not display statistically significant differences between the post‐cryotherapy and the control conditions with low effect sizes. Dynamic ML indices significantly increased following the cryotherapy application compared to the control exhibiting a moderate effect size indicating decreased balance following cryotherapy application. No differences were noted between experimental and control conditions for the dynamic AP or overall balance indices while a small effect size was noted for both.

Conclusions:

The results suggest that cryotherapy to the ankle has a negative effect on the ML component of dynamic balance following ice water immersion.

Clinical Relevance:

Immediate return to play following cryotherapy application is cautioned given the decreased dynamic ML balance and potential for increased injury risk.

Level of Evidence:

3b Case‐control study

Background:

The ligament sprain of the lateral ankle is the most frequent injury that occurs when participating in sports. Whole body vibration (WBV) is a training method that has been recently introduced as a rehabilitative tool for treatment of athletes. It has been hypothesized that the transmission of mechanical oscillations from the vibrating platform may lead to physiological changes in muscle spindles, joint mechanoreceptors, as well as improve balance.

Propose:

The aim of this study was to assess the effects of a 6‐week WBV training program on the reflex response mechanism of the peroneus longus (PL), peroneus brevis (PB) and anterior tibialis (AT) muscles in ankle inversion at 30º from horizontal, in a static position.

Methods:

This study was a single‐blinded and randomized controlled trial. Forty‐four healthy, physically active participants were randomly split into two groups: the experimental group (n = 26) (the WBV training) and control group (n = 18). Reaction time (RT), maximum electromyographic (EMG) peak (peak EMG), time to the maximum peak EMG (peak EMG time) and reflex electrical activity of all the muscles were assessed before and after the WBV training through surface EMG.

Results:

After 6‐weeks WBV training, there were no significant changes in the variables analysed for all the muscles involved.

Conclusion:

A 6‐week WBV training does not improve the reflex response mechanism of the lateral stabilizing muscles of the ankle.

Level of evidence:

1b

Purpose/Background:

To compare the acute effects of two passive stretches on pectoralis minor length and scapular kinematics among a group of collegiate swimmers.

Methods:

The study was a descriptive design with repeated measures. All procedures were conducted in a biomechanics laboratory and collegiate swimming facility. Fifty asymptomatic shoulders from 29 NCAA swimmers were used (15 control shoulders, 17 focused stretch shoulders, 18 gross stretch shoulders). Pre‐ and post‐test linear pectoralis minor length, as well as scapular kinematics (upward/downward rotation, external/internal rotation, anterior/posterior tilt) were measured as dependent variables. Pectoralis minor length was measured using a standard tape measure and three‐dimensional scapular kinematics were measured using an electromagnetic capture system.

Results:

The gross stretch shoulders had a significant increase in pectoralis minor length compared to the control shoulders (P=.007). There were no other significant changes in length for either the focused stretch or control shoulders (P>.07). No statistically significant (P>.08) differences for all three scapular kinematic variables were found among any of the three groups (P>.08).

Conclusions:

Our results revealed no acute improvements of scapular upward rotation, external rotation, or posterior tilt after the application of either passive stretch maneuver to the pectoralis minor muscle.

Level of Evidence:

2b

Background/Purpose:

Studies that have aimed to compare different strategies to improve functional capacity have produced controversial results. Furthermore, such studies have focused solely on dependent individuals. In contrast, the present study aimed to compare traditional training to functional training for independent individuals. The purpose of this study was to compare traditional training to functional training in healthy and independent middle‐aged adults (40‐60 years old) and elderly subjects (older than 60 years old).

Methods:

One hundred and one subjects (54.75 ± 8.84 years) were divided into two groups that each performed 24 sessions of a training protocol twice per week. The subjects were assessed using quantitative (Y‐Balance Test) and qualitative methods (Functional Movement Screen™). The individuals were compared by observing changes between pretest and posttest according to their intervention group, sex and age.

Results:

When the entire sample was considered, the results showed that there were no differences in improvement between the training protocols. However, when specific groups were analyzed, functional training was less effective for women compared to men in the same group (Z=–2.598; p=0.009; effect size=0.43) and compared to women in the conventional group (Z=–2.704; p=0.007; effect size=0.41).

Conclusions:

There were no differences between the two protocols in their ability to improve functional capacity as measured by the two chosen outcome measures. However, each subject's condition before the intervention must be considered. Some individuals may require additional basic training or specific training. In the current study, the women may have needed to improve their basic capabilities before practicing more specific training protocols.

Level of evidence:

2b. This is a pre‐ and post‐intervention analysis using within‐group and between‐groups comparisons.

Purpose/Background:

To develop a consensus on the critical constructs necessary to be included in a physical performance assessment checklist (PPAC) to assess an athlete's ability for return to sport following a lower extremity injury.

Methods:

The study used a 3‐round Delphi method to finalize the PPAI originally developed by a panel of experts. Fourteen Delphi representative sample participants were randomly derived from the authors of peer‐reviewed publications of lower extremity injuries. Nine participants completed all 3 rounds.

Results:

Throughout the 3 rounds, the 10 initial constructs were modified and revised to produce the finalized PPAC consisting of 12 constructs necessary to consider for an athlete's return to sport after a lower extremity injury.

Conclusions:

This instrument can be used as a checklist to advocate for prospective batteries of physical performance tests to incorporate the elements identified by this study.

Level of Evidence:

5

Comprehensive Arthroscopic Management (CAM) is a new glenohumeral debridement procedure developed as a joint preserving alternative to total shoulder arthroplasty (TSA). The procedure consists of several arthroscopic components including: A. scar tissue and chondral debridement, B. synovectomy, C. inferior humeral osteoplasty, D. capsular release, E. axillary nerve decompression, and F. tenodesis of the long head of the biceps. In this case, an active, middle age patient who failed physical therapy treatment and corticosteroid injections was evaluated and diagnosed with glenohumeral osteoarthritis. Anterior‐ posterior (AP) and axillary radiographs showed grade IV changes of the articular cartilage, confirming the diagnosis. The patient was not an ideal candidate for TSA because of her age, activity level, and concern for implant survival; therefore surgical intervention was performed using the CAM procedure. After the surgery, the patient demonstrated increased joint space as shown using radiographic imaging. The patient underwent intensive postoperative rehabilitation with a heavy emphasis on joint range of motion (ROM) and capsular mobility. By eight weeks she achieved 85% active ROM compared to her uninvolved shoulder, and a 55% improvement on the Pennsylvania Shoulder Score. Radiographic imaging provided an understanding of the severity of the arthritic changes present in this patient, identified the limited potential of continued conservative management, and showed structural changes that may be correlated with improved function following the surgical intervention. For patients less than 55 years of age diagnosed with severe glenohumeral osteoarthritis, the CAM procedure and intensive, motion focused therapy presents a promising treatment combination.

Level of Evidence:

IIIb

Dynamic neuromuscular (core) stability is necessary for optimal athletic performance and is not achieved purely by adequate strength of abdominals, spinal extensors, gluteals or any other musculature; rather, core stabilization is accomplished through precise coordination of these muscles and intra‐abdominal pressure regulation by the central nervous system. Understanding developmental kinesiology provides a framework to appreciate the regional interdependence and the inter‐linking of the skeleton, joints, musculature during movement and the importance of training both the dynamic and stabilizing function of muscles in the kinetic chain. The Dynamic Neuromuscular Stabilization (DNS) approach provides functional tools to assess and activate the intrinsic spinal stabilizers in order to optimize the movement system for both pre‐habilitation and rehabilitation of athletic injuries and performance.

Level of Evidence:

5

Thoracic outlet syndrome (TOS) is a well‐described condition resulting from compression of the brachial plexus, subclavian artery and/or vein. Though symptoms of pain, numbness, tingling and signs of muscular weakness associated with this condition usually begin insidiously, on rare occasions the presentation is of acute onset and may represent an acute vascular compression. An unusual form of “effort” thrombosis of the subclavian vein may require emergency care in order to ensure controlled clot lysis and thrombus dissolution. Confirmation of subclavian thrombus is obtained by venography and makes use of real time videography to assess for venous flow impairment. Definitive treatment for the underlying cause of this form of TOS is first rib resection and scalenectomy. This case report presents a competitive swimmer who developed an acute onset of limb cyanosis and turgidity during swim training. Awareness of the possibility of acute thrombosis obstructing venous return and producing such signs and symptoms should lead the astute clinician to consider recommending contrast venography to assess the lesion and lead to appropriate medical intervention.

The acute anterior dislocation of the glenohumeral joint (GHJ) poses a challenge to sports medicine providers at all levels and in all settings. This macrotraumatic injury occurs in athletes who participate in a wide variety of sports, most typically as a result of contact or collision mechanisms. Quick and effective relocation of the GHJ is an important skill for on the sideline or on the field management of this type of dislocation when appropriate and allowable by facility protocol. This clinical suggestion describes one possible technique for athlete self‐reduction that may be appropriate in some circumstances. This is in contrast to forcible reduction by the health professional, which is outside of the scope of this clinical commentary.

Level of Evidence:

5

Background:

Complete rupture of the distal tendon of the biceps brachii is relatively rare and there is little information to guide therapists in rehabilitation after this injury. The purposes of this case report are to review the rehabilitation concepts used for treating such an injury, and discuss how to modify exercises during rehabilitation based on patient progression while adhering to physician recommended guidelines and standard treatment protocols.

Case Presentation:

The patient was an active 38‐year old male experienced in weight‐training. He presented with a surgically repaired right distal biceps tendon following an accident on a trampoline adapted with a bungee suspension harness. The intervention focused on restoring range of motion and strengthening of the supporting muscles of the upper extremity without placing undue stress on the biceps brachii.

Outcomes:

The patient was able to progress from a moderate restriction in ROM to full AROM two weeks ahead of the physician's post‐operative orders and initiate a re‐strengthening protocol by the eighth week of rehabilitation. At the eighth post‐operative week the patient reported no deficits in functional abilities throughout his normal daily activities with his affected upper extremity.

Discussion:

The results of this case report strengthen current knowledge regarding physical therapy treatment for a distal biceps tendon repair while at the same time providing new insights for future protocol considerations in active individuals. Most current protocols do not advocate aggressive stretching, AROM, or strengthening of a surgically repaired biceps tendon early in the rehabilitation process due to the fear of a re‐rupture. In the opinion of the authors, if full AROM can be achieved before the 6th week of rehabilitation, initiating a slow transition into light strengthening of the biceps brachii may be possible.

Level of evidence:

4‐Single Case report

Background and purpose:

Mid‐portion Achilles tendinopathy (AT) is a common injury among runners and recreational athletes. The conservative management of mid‐portion AT typically includes eccentric exercise as recommended in multiple systematic reviews and practice guidelines. However, an eccentric program typically requires 12 weeks for satisfactory results and problems with compliance have been reported. Astym® is a non‐invasive instrument assisted soft tissue treatment that can be used in the management of tendinopathies but there is limited published research on this treatment approach. The purpose of this case report is to present the management and outcomes of a patient with AT who was treated with eccentric exercise and Astym®.

Case Description:

The patient was a 56‐year‐old recreational tennis player referred to physical therapy with mid‐portion AT of 6 weeks duration. Her primary complaints were pain with walking and an inability to play tennis. She was treated in physical therapy 2 times per week for 10 visits with treatment focused on Astym® and eccentric exercise.

Outcomes:

By her 6th visit she subjectively reported being 75% functionally normal and was able to play a doubles tennis match. After 10 visits she reported that she was pain‐free and able to play singles and doubles tennis without limitation.

Discussion:

The patient in this case report was able to return to her normal activities after 5 weeks of treatment with Astym® and eccentric exercise. These results were achieved in less than half of the time commonly reported with eccentric exercise alone.

Conclusion:

This case suggests that Astym® combined with eccentric exercise may be a beneficial treatment approach for patients with AT.

Background and Purpose:

Recently, the trend among physical training and rehabilitation professionals is the use of resistance exercise on unstable equipment in order to increase the effort of the agonist and stabilizing muscles. It is unknown if performing exercises on unstable surfaces provides a greater training stimulus as compared to training on a stable training surface. Therefore, the purpose of this research was to compare the effect that push‐up training on stable and unstable surfaces had on strength performance in healthy young men.

Methods:

Thirty subjects with experience in resistance training participated in push‐up training two days per week for eight weeks on one of three different surfaces: the floor (Tp), the T‐Bow® (TBp) or the BOSU® (Bp).

Results:

Strength, as measured by one repetition maximum (1‐RM) and muscle endurance, as measured by number of pushups performed did not improve significantly (p>0.05) for any of the intervention groups.

Conclusions:

The addition of unstable surfaces in push‐up training does not provide greater improvement in muscular strength and endurance than push up training performed on a stable surface in young men.

Levels of Evidence:

3b

Background:

Quantification of dynamic balance is essential to assess a patient's level of injury or ability to function so that a proper plan of care may commence. In spite of comprehensive utilization of dual‐tasking in balance assessment protocols, a lack of sufficient reliability data is apparent.

Purpose:

The purpose of the present study was to determine the intra‐ and inter‐session reliability of dynamic balance measures obtained using the Biodex Balance System® (BBS) for a group of athletes who had undergone anterior cruciate ligament reconstruction (ACLR) and a matched control group without ACLR, while using a dual‐task paradigm.

Methods:

Single‐limb postural stability was assessed in 15 athletes who had undergone ACLR and 15 healthy matched controls. The outcome variables included measures of both postural and cognitive performance. For measuring postural performance, the overall stability index (OSI), anterior‐posterior stability index (APSI), and medial‐lateral stability index (MLSI), were recorded. Cognitive performance was evaluated by measuring error ratio and average reaction time. Subjects faced 4 postural task difficulty levels (platform stabilities of 8 and 6 with eyes open and closed), and 2 cognitive task difficulty levels (with or without auditory Stroop task). During dual task conditions (conditions with Stroop task), error ratio and average reaction time were calculated.

Results:

Regarding intrasession reliability, ICC values of test session were higher for MLSI [ACL‐R group (0.83‐0.95), control group (0.71‐0.95)] compared to OSI [ACL‐R group (0.80‐0.92), control group (0.67‐0.95)] and APSI [ACL‐R group (0.73‐0.90), control group (0.62‐0.90)]. Furthermore, ICC values of first test session were higher in reaction time [ACL‐R group (0.92‐0.95), control group (0.80‐0.92)] than error ratio [ACL‐R group (0.72‐0.88), control group (0.61‐0.83)]. ICC values of retest session were higher for MLSI [ACL‐R group (0.83‐0.94), control group (0.87‐0.93)] than OSI [ACL‐R group (0.81‐0.91), control group (0.83‐0.93)] and APSI [ACL‐R group (0.73‐0.90), control group (0.53‐0.90)]. Moreover, ICC values of retest session were higher in reaction time [ACL‐R group (0.89‐0.98), control group (0.80‐0.92)] equated with error ratio [ACL‐R group (0.73‐0.87), control group (0.57‐0.79)].

With respect to intersession reliability, ICC values were higher for MLSI [ACL‐R group (0.72‐0.96), control group (0.75‐0.92)] than OSI [ACL‐R group (0.55‐0.91), control group (0.64‐0.87)] and APSI [ACL‐R group (0.55‐0.79), control group (0.46‐0.89)]. Additionally, ICC values were higher in reaction time [ACL‐R group (0.87‐0.95), control group (0.68‐0.81)] in contrast to error ratio [ACL‐R group (0.42‐0.64), control group (0.54‐0.74)].

Conclusion:

Biodex Balance System® measures of postural stability demonstrated moderate to high reliability in athletes with and without ACLR during dual‐tasking. Results of the current study indicated that assessment of postural and cognitive performance in athletes with ACLR may be reliably incorporated into the evaluation of functional activity.

Level of Evidence:

2b

Background Context:

Low back pain (LBP) is a prevalent disorder in society that has been associated with increased loss of work time and medical expenses. A common intervention for LBP is spinal manipulation, a technique that is not specific to one scope of practice or profession.

Purpose:

The purpose of this systematic review was to examine the effectiveness of physical therapy spinal manipulations for the treatment of patients with low back pain.

Methods:

A search of the current literature was conducted using PubMed, CINAHL, SPORTDiscus, Pro Quest Nursing and Allied Health Source, Scopus, and Cochrane Controlled Trials Register. Studies were included if each involved: 1) individuals with LBP; 2) spinal manipulations performed by physical therapists compared to any control group that did not receive manipulations; 3) measurable clinical outcomes or efficiency of treatment measures, and 4) randomized control trials. The quality of included articles was determined by two independent authors using the criteria developed and used by the Physiotherapy Evidence Database (PEDro).

Results:

Six randomized control trials met the inclusion criteria of this systematic review. The most commonly used outcomes in these studies were some variation of pain rating scales and disability indexes. Notable results included varying degrees of effect sizes favoring physical therapy spinal manipulations and minimal adverse events resulting from this intervention. Additionally, the manipulation group in one study reported statistically significantly less medication use, health care utilization, and lost work time.

Conclusion:

Based on the findings of this systematic review there is evidence to support the use of spinal manipulation by physical therapists in clinical practice. Physical therapy spinal manipulation appears to be a safe intervention that improves clinical outcomes for patients with low back pain.

The management of the skeletally immature athlete sustaining injury to the anterior cruciate ligament and other knee structures provides multiple challenges for both the treating clinicians and parents of the injured child. The diagnostic process and subsequent decision making present additional complexities because of the developmental anatomy and the potential for disturbance of normal growth patterns by some surgical interventions. In the following case report, the course to appropriate management of a young athlete is detailed, including the contributions of imaging results. The reconstructive options available to orthopedic surgeons and the patient's post‐operative progression are also briefly discussed. Rehabilitation practitioners require an understanding of the unique issues present when providing care for pediatric and adolescent athletes with knee injuries in order to assist in optimal decision making in the phases during which they are involved.

Level of Evidence:

5 (Single Case Report)

Background/Purpose:

Frontal plane running mechanics may contribute to the etiology or exacerbation of common running related injuries. Hip strengthening alone may not change frontal plane hip and knee joint running mechanics. The purpose of the current study was to evaluate whether a training program including visual, verbal, and tactile feedback affects hip and knee joint frontal plane running mechanics among females with evidence of altered weight bearing kinematics.

Methods:

The knee frontal plane projection angle of 69 apparently healthy females was determined during a single leg squat. The twenty females from this larger sample who exhibited the most acute frontal plane projection angle (medial knee position) during this activity were chosen to participate in this study (age = 20 ± 1.6 years, height = 167.9 ± 6.0 cm, mass = 63.2 ± 8.3 kg, Tegner Activity Rating mode = 7.0). Participants engaged in a 4‐week movement training program using guided practice during weight bearing exercises with visual, verbal, and tactile feedback regarding lower extremity alignment. Paired t‐tests were used to compare frontal plane knee and hip joint angles and moments before and after the training program.

Results:

After training, internal hip and knee abduction moments during running decreased by 23% (P=0.007) and 29% (P=0.033) respectively. Knee adduction and abduction excursion decreased by 2.1° (P = 0.050) and 2.7° (P=0.008) respectively, suggesting that less frontal plane movement of the knee occurred during running after training. Peak knee abduction angle decreased 1.8° after training (P=0.051) although this was not statistically significant. Contralateral peak pelvic drop, pelvic drop excursion, peak hip adduction angle, hip adduction excursion, and peak knee adduction angle were unchanged following training.

Conclusions:

A four week movement training program may reduce frontal plane hip and knee joint mechanics thought to contribute to the etiology and exacerbation of some running related injuries.

Level of Evidence:

Level 4

Purpose/Background:

Researchers have observed differences in muscle activity patterns between males and females during functional exercises. The research methods employed have used various step heights and lunge distances to assess functional exercise making gender comparisons difficult. The purpose of this study was to examine core and lower extremity muscle activity between genders during single‐limb exercises using adjusted distances and step heights based on a percentage of the participant's height.

Methods:

Twenty men and 20 women who were recreationally active and healthy participated in the study. Two‐dimensional video and surface electromyography (SEMG) were used to assess performance during three exercise maneuvers (step down, forward lunge, and side‐step lunge). Eight muscles were assessed using SEMG (rectus abdominus, external oblique, erector spinae, rectus femoris, tensor fascia latae, gluteus medius, gluteus maximus, biceps femoris). Maximal voluntary isometric contractions (MVIC) were used for each muscle and expressed as %MVIC to normalize SEMG to account for body mass differences. Exercises were randomized and distances were normalized to the participant's lower limb length. Descriptive statistics, mixed‐model ANOVA, and ICCs with 95% confidence intervals were calculated.

Results:

Males were taller, heavier, and had longer leg length when compared to the females. No differences in %MVIC activity were found between genders by task across the eight muscles. For both males and females, the step down task resulted in higher %MVIC for gluteus maximus compared to lunge, (p=0.002). Step down exercise produced higher %MVIC for gluteus medius than lunge (p=0.002) and side step (p=0.006). ICC3,3 ranged from moderate to high (0.74 to 0.97) for the three tasks.

Conclusions:

Muscle activation among the eight muscles was similar between females and males during the lunge, side‐step, and step down tasks, with distances adjusted to leg length. Both males and females elicited higher muscle activity for gluteus maximus and gluteus medius as compared to the trunk, hip flexors, or hamstring muscles. However these values were well below the recruitment levels necessary for strengthening in both genders.

Level of evidence:

4

Over the last decade, participation in organized youth sports has risen to include over 35 million contestants.1 The rise in participation has brought about an associated increase in both traumatic and overuse injuries in the youth athlete, which refers to both children and adolescents within a general age range of seven to 17. Exposure rates alone do not account for the increase in injuries. Societal pressures to perform at high levels affect both coaches and athletes and lead to inappropriate levels of training intensity, frequency, and duration. In this environment high physiologic stresses are applied to the immature skeleton of the youth athlete causing injury. Typically, since bone is the weakest link in the incomplete ossified skeleton, the majority of traumatic injuries result in fractures that occur both at mid‐shaft and at the growth centers of bone. The following clinical commentary describes the common traumatic sports injuries that occur in youth athletes, as well as those which require rapid identification and care in order to prevent long term sequelae.

Background:

Rehabilitation programs for patients with patellofemoral dysfunction aim to recruit the vastus medialis obliquus muscle (VMO) in an attempt to reduce pain and to improve patellar tracking.

Objectives:

The aim of the present study was to use surface EMG to assess the effectiveness of two isometric submaximal contractions (10% and 60% of maximal voluntary contraction, MVC) in promoting preferential activation of VMO over vastus medialis longus (VML) and vastus lateralis (VL) in open and closed kinetic chain isometric exercises with the knee joint fixed at 30, 60 and 90 degrees of flexion.

Methods and Measures:

Surface electromyography (EMG) signals were recorded with linear adhesive arrays of four electrodes from fourteen healthy young men (age 23.5±3.2, mean±SD) during isometric knee extension contractions at 10% and 60% of the maximum voluntary contraction (MVC) for 1 min and 20 s respectively at 30, 60 and 90 degrees of knee flexion. Initial values and rate of change (slope) of mean frequency (MNF), average rectified value (ARV) and conduction velocity (CV) of the EMG signal were calculated.

Results:

Comparisons between the force levels produced at 10% and 60% MVC revealed that the initial values of ARV and CV for the VL, VML and VMO muscle were greater at 60% MVC compared to 10% MVC (3‐way ANOVA; F=536; p<0.001, F=49: p<0.01 for ARV and CV respectively). Comparisons between the different muscles demonstrated lower initial values of CV for VMO compared to VL and VLM at 10% and 60% of MVC (F=15; p<0.05). In addition, initial estimates of ARV were higher for VMO compared to VML at both force levels (F=66; p<0.05). Comparisons between open and closed kinetic chain exercises revealed higher initial estimates of ARV for open kinetic chain knee extension at both force levels (F=62; p<0.01). In addition, the absolute value of MNF slope appeared to increase at higher angles for closed kinetic chain at 60% MVC while it was minimum at 60° degrees for open kinetic chain. No significant differences were observed in the rate of change of CV and MNF among the three muscles.

Conclusions:

Based on the results of this study, both open and closed kinetic chain exercise similarly activate the three portions of the quadriceps muscle, suggesting that selective training of the vastii muscle is not achievable in these conditions.

Background:

Posterior shoulder tightness (PST) has been implicated in the etiology of numerous shoulder disorders. Although reliable and valid measures have been described for the non‐operative population one does not exist for the post‐operative population.

Study Design:

Blinded repeated measures design.

Purpose:

Investigate the intrarater reliability, minimal detectable change at the 90% confidence interval (MDC90) and construct validity of an inclinometric measurement designed to quantify PST in the post‐operative population.

Methods:

One investigator performed PST measurements on the operative shoulder of 23 participants. Passive internal and external rotation measurements were performed for the validity component of the investigation.

Results:

Intrarater reliability using an intraclass correlation coefficient (ICC) model 3,k was good (ICC = 0.79). The MDC90 indicated that a change of greater than or equal to 8 degrees would be required to be 90% certain that a change in the measurement would not be the result of inter‐trial variability or measurement error. Construct validity was supported by a statistically significant relationship between PST and internal rotation r = 0.54 and by a relationship between PST and external rotation r = 0.30 which was not statistically significant.

Conclusion:

The sidelying procedure described in this investigation appears to be a reliable and valid means for quantifying PST in the post‐operative population. Moreover, the use of inclinometry provides an absolute angle of tightness that may be used for intersubject comparison, documenting change, and to determine reference values.

Level of Evidence:

Therapy, level 2b

Background:

The shoulder, particularly the glenohumeral joint with its predominant reliance upon soft tissues for stability is prone to injury among the cricketers who bowl regularly. These shoulder injuries are more common in spin bowlers than fast bowlers. A decreased internal rotational difference and increased external rotational difference exist when comparing the dominant shoulder with non‐dominant shoulder between overarm cricketers and non‐throwing wicket keepers.

Purpose:

To compare the glenohumeral internal and external rotation range of motion differences between fast bowlers and spin bowlers.

Methods:

A cross‐sectional design was utilized for this study. Thirty‐five fast bowlers and 31 spin bowlers from an elite group were recruited based on the selection criteria. Glenohumeral passive internal and external rotational differences between dominant and non‐dominant shoulders were measured using a standardized mechanical inclinometer.

Results:

Independent t‐tests revealed a statistically significant difference for external rotational difference (p=0.005) between fast and spin bowlers and no such difference for internal rotational difference (p=0.549) between them at 0.05 level.

Conclusion:

External rotational difference is significantly different between fast bowlers and spin bowlers but not internal rotational difference.

Level of Evidence:

Level 4

Background/Purpose:

While elastic resistance training, targeting the upper body is effective for strength training, the effect of elastic resistance training on lower body muscle activity remains questionable. The purpose of this study was to evaluate the EMG‐angle relationship of the quadriceps muscle during 10‐RM knee‐extensions performed with elastic tubing and an isotonic strength training machine.

Methods:

7 women and 9 men aged 28‐67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric contraction phase of a knee extension exercise performed with elastic tubing and in training machine and normalized to maximal voluntary isometric contraction (MVC) EMG (nEMG). Knee joint angle was measured during the exercises using electronic inclinometers (range of motion 0‐90°).

Results:

When comparing the machine and elastic resistance exercises there were no significant differences in peak EMG of the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM) during the concentric contraction phase. However, during the eccentric phase, peak EMG was significantly higher (p<0.01) in RF and VM when performing knee extensions using the training machine. In VL and VM the EMG‐angle pattern was different between the two training modalities (significant angle by exercise interaction). When using elastic resistance, the EMG‐angle pattern peaked towards full knee extension (0°), whereas angle at peak EMG occurred closer to knee flexion position (90°) during the machine exercise. Perceived loading (Borg CR10) was similar during knee extensions performed with elastic tubing (5.7±0.6) compared with knee extensions performed in training machine (5.9±0.5).

Conclusion:

Knee extensions performed with elastic tubing induces similar high (>70% nEMG) quadriceps muscle activity during the concentric contraction phase, but slightly lower during the eccentric contraction phase, as knee extensions performed using an isotonic training machine. During the concentric contraction phase the two different conditions displayed reciprocal EMG‐angle patterns during the range of motion.

Level of Evidence:

5

A push for the use of evidence‐based medicine and evidence‐based practice patterns has permeated most health care disciplines. The use of evidence‐based practice in sports physical therapy may improve health care quality, reduce medical errors, help balance known benefits and risks, challenge views based on beliefs rather than evidence, and help to integrate patient preferences into decision‐making. In this era of health care utilization sports physical therapists are expected to integrate clinical experience with conscientious, explicit, and judicious use of research evidence in order to make clearly informed decisions in order to help maximize and optimize patient well‐being. One of the more common reasons for not using evidence in clinical practice is the perceived lack of skills and knowledge when searching for or appraising research. This clinical commentary was developed to educate the readership on what constitutes evidence‐based practice, and strategies used to seek evidence in the daily clinical practice of sports physical therapy.

Writing a scientific manuscript can be a consuming, but rewarding task with a number of intrinsic and extrinsic benefits. The ability to write a scientific manuscript is typically not an emphasized component of most entry‐level professional programs. The purpose of this overview is to provide authors with suggestions to improve manuscript quality and to provide mechanisms to avoid common manuscript mistakes that are often identified by journal reviewers and editors.