Underestimation of Staphylococcus aureus (MRSA and MSSA) carriage associated with standard culturing techniques: One third of carriers missed

OBJECTIVES

Nasal carriers of Staphylococcus (S.) aureus (MRSA and MSSA) have an increased risk for healthcare-associated infections. There are currently limited national screening policies for the detection of S. aureus despite the World Health Organization's recommendations. This study aimed to evaluate the diagnostic performance of molecular and culture techniques in S. aureus screening, determine the cause of any discrepancy between the diagnostic techniques, and model the potential effect of different diagnostic techniques on S. aureus detection in orthopaedic patients.

METHODS

Paired nasal swabs for polymerase chain reaction (PCR) assay and culture of S. aureus were collected from a study population of 273 orthopaedic outpatients due to undergo joint arthroplasty surgery.

RESULTS

The prevalence of MSSA nasal colonization was found to be between 22.4% to 35.6%. The current standard direct culturing methods for detecting S. aureus significantly underestimated the prevalence (p = 0.005), failing to identify its presence in approximately one-third of patients undergoing joint arthroplasty surgery.

CONCLUSION

Modelling these results to national surveillance data, it was estimated that approximately 5000 to 8000 S. aureus surgical site infections could be prevented, and approximately $140 million to $950 million (approximately £110 million to £760 million) saved in treatment costs annually in the United States and United Kingdom combined, by using alternative diagnostic methods to direct culture in preoperative S. aureus screening and eradication programmes.Cite this article: S. T. J. Tsang, M. P. McHugh, D. Guerendiain, P. J. Gwynne, J. Boyd, A. H. R. W. Simpson, T. S. Walsh, I. F. Laurenson, K. E. Templeton. Underestimation of Staphylococcus aureus (MRSA and MSSA) carriage associated with standard culturing techniques: One third of carriers missed. Bone Joint Res 2018;7:79-84. DOI: 10.1302/2046-3758.71.BJR-2017-0175.R1.

The Effect of Postoperative KT-1000 Arthrometer Score on Long-Term Outcome After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Many long-term studies have looked at outcomes after anterior cruciate ligament reconstruction (ACLR), but none have correlated long-term outcomes with postoperative laxity greater than 5 mm. It has been stated previously that more than 5 mm of postoperative graft laxity constituted a procedural failure.

PURPOSE

To directly compare tight grafts (<3 mm) and loose grafts (>5 mm) to determine the effect of graft laxity, as measured by KT-1000 arthrometer, after ACLR on long-term clinical outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

The study included 171 consecutive patients who had undergone transtibial bone-patellar tendon-bone ACLR between 1992 and 1998. At 6, 12, and 24 months postoperatively (the immediate postoperative period), patients were evaluated. Group A included patients with a maximal side-to-side (STS) difference in the immediate postoperative period of less than 3 mm (tight grafts), and group B included patients with a maximal STS difference of greater than 5 mm (loose grafts). Any patient with a history of ipsilateral or contralateral ACLR or ACL injury, meniscectomy, or cartilage restoration was excluded. Patients were prospectively followed to long-term follow-up, when a telephone interview was conducted regarding knee function and to document Lysholm, Tegner, Knee injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) subjective outcome scores.

RESULTS

Eighty-seven patients met inclusion criteria: 66 tight grafts (group A) and 21 loose grafts (group B). The mean ± SD time to follow-up was 16.3 ± 1.5 years in group A (n = 46) and 16.8 ± 1.3 years in group B (n = 15). Tegner ( P = .77), Lysholm ( P = .85), KOOS ( P = .96), and IKDC ( P = .42) were found to have no statistically significant difference between groups at long-term follow-up. Both Tegner and Lysholm scores significantly improved in tight and loose grafts in the immediate postoperative period as well as at long-term follow-up compared with preoperatively. There were 2 ACL revisions in group A and none in group B. Eleven of 46 patients (24%) in group A required subsequent procedures versus 1 of 15 patients (6.7%) in group B ( P = .146).

CONCLUSION

Postoperative laxity of greater than 5 mm STS difference as measured by KT-1000 arthrometer does not appear to place patients at a worse clinical outcome at long-term follow-up, nor does it lead to significantly more subsequent procedures. In addition, transtibial ACLR can provide excellent clinical results at long-term follow-up.

The efficacy of cooling with phase change material for the treatment of exercise-induced muscle damage: pilot study

Post-exercise cryotherapy treatments are typically short duration interventions. This study examined the efficacy of prolonged cooling using phase change material (PCM) on strength loss and pain after eccentric exercise. Eight adults performed 120 bilateral eccentric quadriceps contractions (90% MVC). Immediately afterwards, frozen PCM packs (15°C) were placed over the quadriceps, with room temperature PCM packs on the contralateral quadriceps. Skin temperature was recorded continually (6 h PCM application). Isometric quadriceps strength and soreness were assessed before, 24, 48, 72 and 96 h post-exercise. The protocol was repeated 5 months later, with room temperature PCM applied to both legs. There were three treatments: legs treated with 15°C PCM packs (direct cooling), legs treated with room temperature PCM packs contralateral to the 15°C PCM packs (systemic cooling), and legs tested 5 months later both treated with room temperature PCM packs (control). Skin temperature was 9°C-10°C lower with direct cooling versus systemic cooling and control (P < 0.01). Strength loss and soreness were less (P < 0.05) with direct cooling versus systemic cooling and control (strength 101%, 94%, 93%, respectively; pain 1.0, 2.3, 2.7, respectively). Six hours of PCM cooling was well tolerated and reduced strength loss and pain after damaging exercise.

Functional Outcomes After Double-Row Versus Single-Row Rotator Cuff Repair: A Prospective Randomized Trial

Background:

The functional benefits of double-row (DR) versus single-row (SR) rotator cuff repair are not clearly established.

Purpose:

To examine the effect of DR versus SR rotator cuff repair on functional outcomes and strength recovery in patients with full-thickness tears.

Study Design:

Randomized controlled trial; Level of evidence, 2.

Methods:

Forty-nine patients were randomized to DR or SR repairs; 36 patients (13 women, 23 men; mean age, 62 ± 7 years; 20 SR, 16 DR) were assessed at a mean 2.2 ± 1.6 years after surgery (range, 1-7 years; tear size: 17 medium, 13 large, 9 massive). The following data were recorded prior to surgery and at follow-up: Penn shoulder score, American Shoulder and Elbow Surgeons (ASES), and Simple Shoulder Test (SST) results; range of motion (ROM) for shoulder flexion, external rotation (ER) at 0° and 90° of abduction, and internal rotation (IR) at 90° of abduction; and shoulder strength (Lafayette manual muscle tester) in empty- and full-can tests, abduction, and ER at 0° of abduction. Treatment (SR vs DR) × time (pre- vs postoperative) mixed-model analysis of variance was used to assess the effect of rotator cuff repair.

Results:

Rotator cuff repair markedly improved Penn, ASES, and SST scores (P < .001), with similar improvement between SR and DR repairs (treatment × time, P = .38-.10) and excellent scores at follow-up (DR vs SR: Penn, 91 ± 11 vs 92 ± 11 [P = .73]; ASES, 87 ± 12 vs 92 ± 12 [P = .21]; SST, 11.4 ± 1.0 vs 11.3 ± 1.0 [P = .76]). Patients with DR repairs lost ER ROM at 0° of abduction (preoperative to final follow-up, 7° ± 10° loss [P = .013]). ER ROM did not significantly change with SR repair (5° ± 14° gain, P = .16; treatment by time, P = .008). This effect was not apparent for ER ROM at 90° of abduction (treatment × time, P = .26). IR ROM improved from preoperative to final follow-up (P < .01; SR, 17° ± 27°; DR, 7° ± 21°; treatment × time, P = .23). Rotator cuff repair markedly improved strength in empty-can (54%), full-can (66%), abduction (47%), and ER (54%) strength (all P < .001), with no difference between SR and DR repairs (P = .23-.75). All clinical tests with the exception of the lift-off test were normalized at follow-up (P < .05).

Conclusion:

Outcomes were not different between SR or DR repair, with generally excellent outcomes for both groups. Rotator cuff repair and subsequent rehabilitation markedly improved shoulder strength.

The Effect of a High Pitch Volume on Musculoskeletal Adaptations in High School Baseball Pitchers

BACKGROUND

Shoulder range of motion and strength adaptations occur at an early age in baseball pitchers.

PURPOSE/HYPOTHESIS

The purpose of this study was to examine the effect of pitch volume on in-season and year-to-year range of motion (ROM) and strength adaptations in high school baseball pitchers. The hypothesis was that a high pitch volume will not affect range of motion asymmetries but will impair supraspinatus strength.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Pre- and postseason ROM and strength measures were performed on pitchers from 3 high schools for 4 consecutive seasons, for a total of 95 player-seasons (mean ± SD participant age, 16 ± 1 years). Preseason measures were repeated the next year on players returning to the teams, for a total of 71 consecutive player-seasons. ROM tests included internal-external rotation and posterior shoulder flexibility. Strength tests (hand-held dynamometer) included internal-external rotation, supraspinatus, and scapular retraction. Pitchers were categorized by pitch count for the season (high, >400; moderate, 180-400; low, <180). ROM and strength changes in the dominant versus nondominant arm were assessed by analysis of variance.

RESULTS

Dominant versus nondominant ROM differences did not change from pre- to postseason (P = .36-.99) or from one year to the next (P = .46-.86), with no effect of pitch volume (P = .23-.87). Supraspinatus strength decreased in the dominant arm during the season, with 13% loss in high-volume pitchers (P < .001) and insignificant losses in moderate- (6%) and low-volume pitchers (2%). Strength in other tests was unaffected by pitch volume. Consistent with physical development, strength increased bilaterally from one year to the next (supraspinatus, 12%; external rotation, 15%; internal rotation, 14%; scapular retraction, 23%; P < .001). Supraspinatus strength gain in the dominant arm was affected by prior pitch volume (P = .02): 24% in low-volume pitchers (P < .01), with no significant change in moderate-volume (0%; P = .99) or high-volume (5%; P = .99) pitchers.

CONCLUSION

Dominant versus nondominant ROM differences did not progress during the season, or from one year to the next, and were unaffected by pitch volume. A high pitch volume was associated with in-season supraspinatus weakness and diminished strength gains from one year to the next. In conclusion, a high pitch volume appeared to have a catabolic effect on supraspinatus strength.

Effect of an eccentrically biased hamstring strengthening home program on knee flexor strength and the length-tension relationship

The purposes of this study were to document relative activation intensities of the hamstrings and gluteus maximus during 4 eccentric hamstring strengthening exercises and to assess the effects of a short-term strengthening program comprised of these exercises on knee flexor strength and the length-tension relationship. Twelve healthy subjects participated in this study. Electromyographic (EMG) activities from the biceps femoris, semitendinosus, and gluteus maximus were recorded as subjects performed (a) standing hip extension with elastic resistance, (b) trunk flexion in single limb stance (diver), (c) standing split (glider), and (d) supine sliding bridge (slider). Baseline isometric knee flexor strength was measured at 90, 70, 50, and 30° of flexion at the knee with the subject seated and the hip flexed to 50° from horizontal. After completing the 4-week training program, strength tests were repeated. Repeated-measures analysis of variance were used to compare EMG activity between muscles and to assess angle-specific strength improvements. Hamstring activity exceeded gluteus maximus activity for resisted hip extension, glider, and slider exercises (p < 0.001) but not for the diver (p = 0.087). Hamstring activation was greatest during the slider and resisted hip extension and lowest during the glider and the diver. Knee flexor strength improved by 9.0% (p = 0.005) but was not angle specific (training by angle p = 0.874). The short-term home training program effectively targeted the hamstrings and resulted in strength gains that were similar at short and long muscle lengths. These data demonstrate that hamstring strength can be improved using eccentrically biased unilateral exercises without the use of weights or other equipments.

Performance Demands in Softball Pitching: A Comprehensive Muscle Fatigue Study

BACKGROUND

Monitoring pitch count is standard practice in minor league baseball but not in softball because of the perception that fast-pitch softball pitching is a less stressful motion.

PURPOSE

To examine muscle fatigue after fast-pitch softball performances to provide an assessment of performance demand.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Bilateral strength measurements (handheld dynamometer) were made on 19 female softball pitchers (mean age [±SD], 15.2 ± 1.2 years) before and after pitching a game (mean number of pitches, 99 ± 21; mean innings pitched, 5 ± 1). A total of 20 tests were performed on the dominant and nondominant sides: forearm (grip, wrist flexion/extension, pronation/supination, elbow flexion/extension), shoulder (flexion, abduction/adduction, external/internal rotation, empty can test), scapula (middle/lower trapezius, rhomboid), and hip (hip flexion/extension, abduction/adduction). Fatigue (percentage strength loss) was categorized based on bilateral versus unilateral presentation using paired t tests: bilateral symmetric (significant on dominant and nondominant and not different between sides), bilateral asymmetric (significant on dominant and nondominant but significantly greater on dominant), unilateral asymmetric (significant on dominant only and significantly greater than nondominant), or unilateral equivocal (significant on dominant only but not different from nondominant).

RESULTS

Bilateral symmetric fatigue was evident for all hip (dominant, 19.3%; nondominant, 15.2%) and scapular tests (dominant, 19.2%; nondominant, 19.3%). In general, shoulder tests exhibited bilateral asymmetric fatigue (dominant, 16.9%; nondominant, 11.6%). Forearm tests were more variable, with bilateral symmetric fatigue in the elbow flexors (dominant, 22.5%; nondominant, 19.2%), and wrist flexors (dominant, 21.6%; nondominant, 19.0%), bilateral asymmetric fatigue in the supinators (dominant, 21.8%; nondominant, 15.5%), unilateral asymmetric fatigue in the elbow extensors (dominant, 22.1%; nondominant, 11.3%), and unilateral equivocal fatigue in the pronators (dominant, 18.8%; nondominant, 15.2%) and grip (dominant, 11.4%; nondominant, 6.6%). The mean (±SD) pitch velocity was 49 ± 4 mph, with a small loss of velocity from the first to last inning pitched (3.4% ± 5.0%, P < .01).

CONCLUSION

Fast-pitch softball pitching resulted in profound bilateral fatigue in the hip and scapular muscles, with more selective fatigue in the shoulder and arm muscles.

CLINICAL RELEVANCE

These findings emphasize the importance of strength in the proximal musculature to provide a stable platform for the arm to propel the ball.

Restoring Isometry in Lateral Ulnar Collateral Ligament Reconstruction

PURPOSE

To ascertain whether placing the humeral attachment of the lateral ulnar collateral ligament (LUCL) at the humeral center of rotation (hCOR) on the humerus would provide the most isometric reconstruction.

METHODS

We analyzed 13 cadaver limbs from mid-humerus to the hand. The morphology of the ligament complex was assessed. The hCOR was then found using radiographic parameters. We chose 7 points on the humerus located at and around the hCOR and 3 points paralleling the supinator crest of the ulna and then calculated distances from these points using a digital caliper at 0°, 30°, 60°, 90°, and 130° flexion. Differences in potential ligamentous lengths (termed graft elongation) were then calculated and statistical analysis was performed.

RESULTS

There was no perfectly isometric point along the humerus or ulna. However, in all specimens the hCOR was the most isometric point for the humeral reconstruction site, with an average graft elongation of 1.1 mm. Differences in humeral tunnel position dramatically affected graft elongation at all 3 ulnar insertions. Overall, ulnar position had a minimal effect on graft elongation.

CONCLUSIONS

Although no perfectly isometric points were found, the humeral center of rotation consistently reproduced the most isometry when assessing graft elongation over range of motion. These data may assist surgeons in proper tunnel placement in LUCL reconstruction.

CLINICAL RELEVANCE

In LUCL reconstruction, the humeral tunnel should be placed as close as possible to the center of rotation, whereas placement on the ulna is less critical.

Development of two real-time multiplex PCR assays for the detection and quantification of eight key bacterial pathogens in lower respiratory tract infections

The frequent lack of a positive and timely microbiological diagnosis in patients with lower respiratory tract infection (LRTI) is an important obstacle to antimicrobial stewardship. Patients are typically prescribed broad-spectrum empirical antibiotics while microbiology results are awaited, but, because these are often slow, negative, or inconclusive, de-escalation to narrow-spectrum agents rarely occurs in clinical practice. The aim of this study was to develop and evaluate two multiplex real-time PCR assays for the sensitive detection and accurate quantification of Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. We found that all eight bacterial targets could be reliably quantified from sputum specimens down to a concentration of 100 CFUs/reaction (8333 CFUs/mL). Furthermore, all 249 positive control isolates were correctly detected with our assay, demonstrating effectiveness on both reference strains and local clinical isolates. The specificity was 98% on a panel of nearly 100 negative control isolates. Bacterial load was quantified accurately when three bacterial targets were present in mixtures of varying concentrations, mimicking likely clinical scenarios in LRTI. Concordance with culture was 100% for culture-positive sputum specimens, and 90% for bronchoalveolar lavage fluid specimens, and additional culture-negative bacterial infections were detected and quantified. In conclusion, a quantitative molecular test for eight key bacterial causes of LRTI has the potential to provide a more sensitive decision-making tool, closer to the time-point of patient admission than current standard methods. This should facilitate de-escalation from broad-spectrum to narrow-spectrum antibiotics, substantially improving patient management and supporting efforts to curtail inappropriate antibiotic use.

Influence of a montmorency cherry juice blend on indices of exercise-induced stress and upper respiratory tract symptoms following marathon running--a pilot investigation

Background

Prolonged exercise, such as marathon running, has been associated with an increase in respiratory mucosal inflammation. The aim of this pilot study was to examine the effects of Montmorency cherry juice on markers of stress, immunity and inflammation following a Marathon.

Methods

Twenty recreational Marathon runners consumed either cherry juice (CJ) or placebo (PL) before and after a Marathon race. Markers of mucosal immunity secretory immunoglobulin A (sIgA), immunoglobulin G (IgG), salivary cortisol, inflammation (CRP) and self-reported incidence and severity of upper respiratory tract symptoms (URTS) were measured before and following the race.

Results

All variables except secretory IgA and IgG concentrations in saliva showed a significant time effect (P <0.01). Serum CRP showed a significant interaction and treatment effect (P < 0.01). The CRP increase at 24 and 48 h post-Marathon was lower (P < 0.01) in the CJ group compared to PL group. Mucosal immunity and salivary cortisol showed no interaction effect or treatment effect. The incidence and severity of URTS was significantly greater than baseline at 24 h and 48 h following the race in the PL group and was also greater than the CJ group (P < 0.05). No URTS were reported in the CJ group whereas 50 % of runners in the PL group reported URTS at 24 h and 48 h post-Marathon.

Conclusions

This is the first study that provides encouraging evidence of the potential role of Montmorency cherries in reducing the development of URTS post-Marathon possibly caused by exercise-induced hyperventilation trauma, and/or other infectious and non-infectious factors.

The influence of age on the viscoelastic stretch response

Passive stretching is commonly recommended to help reduce passive stiffness in older adults, yet their acute viscoelastic stretch responses are still unclear. The purpose of this study was to determine the influence of age on the acute viscoelastic responses to a practical stretching intervention. Twenty-two younger (24 ± 3 years) and 14 older (67 ± 3 years) males performed four 30-second passive stretches of the plantar flexors at a predetermined torque threshold. The absolute and relative change in stress relaxation (decline in torque during each 30-second stretch) and creep (increase in ankle joint angle across the 4 stretches) were recorded. Passive stiffness was calculated as the slope of the angle-torque curve at 10° angle of dorsiflexion. There were no differences for the absolute stress relaxation responses (p ≥ 0.118); however, the relative change in stress relaxation was greater (p = 0.010) for the younger vs. older men at stretch 1 (13.0 vs. 8.6%) and decreased across stretches for the younger men (stretch 1 > 3 and 4; p ≤ 0.018), whereas the older men demonstrated a similar relative change across all 4 stretches (p = 0.917). No age related differences were found for either the absolute or relative creep responses (p ≥ 0.072). Passive stiffness was also greater in the older men (p = 0.044). These results suggest that the younger men displayed a greater initial relative stress relaxation response that diminished across the repeated stretches, whereas the older men experienced a smaller relative response that remained constant across the four 30-second stretches. However, the increase in range of motion for a given stretch torque (creep) across all 4 stretches was similar between groups despite differences in passive stiffness.

Kinematic analysis of the indirect femoral insertion of the anterior cruciate ligament: implications for anatomic femoral tunnel placement

PURPOSE

To determine the effect of debriding the indirect insertion component of the femoral anterior cruciate ligament (ACL) attachment on tibiofemoral kinematics when compared with the intact knee.

METHODS

Knee kinematics were measured in 9 cadaveric knees with the ACL intact, after indirect insertion debridement, and after ACL transection. Three loading conditions were used: (1) a 134-N anterior tibial load, (2) a combined 10-Nm valgus and 5-Nm internal tibial torque, and (3) a simulated robotic pivot shift. Anterior tibial translation (ATT) was recorded in response to anterior and combined loads at 0°, 15°, 30°, 45°, 60°, and 90° of flexion. Posterior tibial translation and external tibial rotation were recorded during the simulated pivot shift.

RESULTS

With an anterior load, indirect insertion debridement increased ATT by 0.37 ± 0.24 mm at 0° (P = .002) and by 0.16 ± 0.19 mm at 15° (P = .033; increases <1 mm in all specimens). ACL transection increased ATT in response to an anterior load (P = .0001) with maximum effect at 15° compared with the intact and debrided states (11.26 ± 1.15 mm and 11.04 ± 1.08 mm, respectively). With a combined load, indirect insertion debridement increased ATT by 0.17 ± 0.11 mm at 0° (P = .001; increases <0.3 mm in all specimens) with no effect at other angles. ACL transection increased ATT in response to a combined load (P = .001) with maximum effect at 15° (4.45 ± 0.85 mm v ACL intact and 4.44 ± 0.84 mm v debrided indirect insertion). In the ACL intact condition, the pivot shift produced 1.29 ± 1.34 mm of posterior tibial translation and 1.54 ± 1.61° of external tibial rotation, as compared with 1.28 ± 1.34 mm and 1.54 ± 1.47°, respectively, after debridement (P = .68 and P = .99, respectively) and 12.79 ± 3.22 mm and 17.60 ± 4.30°, respectively, after ACL transection (P = .0001).

CONCLUSIONS

The indirect femoral ACL insertion contributes minimally to restraint of tibial translation and rotation.

CLINICAL RELEVANCE

Femoral tunnel positioning for anatomic ACL reconstruction should aim to recreate the biomechanically significant direct insertion.

Risk Factors for Shoulder and Elbow Injuries in High School Baseball Pitchers: The Role of Preseason Strength and Range of Motion

BACKGROUND

Shoulder strength and motion deficits in high school baseball pitchers have been implicated in injury risk.

PURPOSE/HYPOTHESIS

To prospectively determine if preseason strength and range of motion (ROM) are predictive of injury in high school baseball pitchers. It was hypothesized that ROM asymmetries and weakness would be predictive of injury.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Preseason strength and ROM measurements were made on 101 pitchers from 4 different high schools over 4 seasons (total 166 pitcher-seasons: 25 freshman, 46 junior varsity, and 95 varsity player-seasons). Glenohumeral internal rotation (IR), glenohumeral external rotation, and posterior shoulder ROM were measured bilaterally. Strength in IR, external rotation, supraspinatus (empty-can test), and scapular retraction was measured bilaterally (handheld dynamometer). Injury incidence (injuries per 1000 pitches) was computed for players categorized as above normal (≥1 SD above the mean), normal (within 1 standard deviation of the mean), and below normal (≤1 SD below the mean) for each potential risk factor. Injury was defined as a missed game or practice because of shoulder or elbow problem.

RESULTS

There were 28 upper extremity injuries (19 shoulder, 9 elbow; incidence, 0.58 injuries/1000 pitches). There was a trend for supraspinatus weakness to be associated with increased injury risk (relative risk [RR], 3.60; 95% CI, 0.75-17.32; P = .09). When analyzing major injuries only (>3 missed games), preseason supraspinatus weakness was significantly associated with increased injury risk (RR, 4.58; 95% CI, 1.40-15.01; P = .02). Paradoxically, pitchers with no IR loss were at increased risk compared with pitchers with ≥20° loss (RR, 4.85; 95% CI, 1.01-23.29; P = .04). Other ROM and strength measures were unrelated to injury risk.

CONCLUSION

Although excessive loss of IR ROM is thought to be a risk factor for injury, the opposite was the case in this study. The absence of IR ROM loss in high school pitchers may indicate inadequate prior exposure to pitching, resulting in increased injury risk. Preseason supraspinatus weakness was associated with increased risk for a major injury, and preventative supraspinatus strengthening may be beneficial.

Is valgus unloader bracing effective in normally aligned individuals: implications for post-surgical protocols following cartilage restoration procedures

PURPOSE

Utilizing valgus unloader braces to reduce medial compartment loading in patients undergoing cartilage restoration procedures may be an alternative to non-weightbearing post-operative protocols in these patients. It was hypothesized that valgus unloader braces will reduce knee adduction moment during the stance phase in healthy subjects with normal knee alignment.

METHODS

Gait analysis was performed on twelve adult subjects with normal knee alignment and no history of knee pathology. Subjects were fitted with an off-the-shelf adjustable valgus unloader brace and tested under five conditions: one with no brace and four with increasing valgus force applied by the brace. Frontal and sagittal plane knee angles and external moments were calculated during stance via inverse dynamics. Analyses of variance were used to assess the effect of the brace conditions on frontal and sagittal plane joint angles and moments.

RESULTS

With increasing tension in the brace, peak frontal plane knee angle during stance shifted from 1.6° ± 4.2° varus without the brace to 4.1° ± 3.6° valgus with maximum brace tension (P = 0.02 compared with the no brace condition). Peak knee adduction moment and knee adduction impulse decreased with increasing brace tension (main effect of brace, P < 0.001). Gait velocity and sagittal plane knee biomechanics were minimally affected.

CONCLUSION

The use of these braces following a cartilage restoration procedure may provide adequate protection of the repair site without limiting the patient's mobility.

The role of cherries in exercise and health

Recently, cherries and cherry products have received growing attention within the literature with regard to their application in both exercise and clinical paradigms. Reported to be high in anti-inflammatory and anti-oxidative capacity, cherries and their constituents are proposed to provide a similar but natural alternative akin to over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) or analgesics. Within exercise paradigms, concern has been raised with regard to the use of products, which inhibit such inflammatory or oxidative actions, because of the possibility of the blunting of physiological training adaptations. Despite this, numerous scenarios exist both within exercise and clinical populations where a goal of optimal recovery time is more important than physiological adaptation. This review critically evaluates and discusses the use of cherries as a supplementation strategy to enhance recovery of muscle function, inhibit exercise-induced inflammation, oxidative stress, and pain primarily; furthermore, the potential application of cherries to clinical populations is discussed.

Repeated bout effect was more expressed in young adult males than in elderly males and boys

This study investigated possible differences using the same stretch-shortening exercise (SSE) protocol on generally accepted monitoring markers (dependent variables: changes in creatine kinase, muscle soreness, and voluntary and electrically evoked torque) in males across three lifespan stages (childhood versus adulthood versus old age). The protocol consisted of 100 intermittent (30 s interval between jumps) drop jumps to determine the repeated bout effect (RBE) (first and second bouts performed at a 2-week interval). The results showed that indirect symptoms of exercise-induced muscle damage after SSE were more expressed in adult males than in boys and elderly males, suggesting that the muscles of boys and elderly males are more resistant to exercise-induced damage than those of adult males. RBE was more pronounced in adult males than in boys and elderly males, suggesting that the muscles of boys and elderly males are less adaptive to exercise-induced muscle damage than those of adult males.

Adaptations in single-leg hop biomechanics following anterior cruciate ligament reconstruction

When a patient performs a clinically normal hop test based on distance, it cannot be assumed that the biomechanics are similar between limbs. The objective was to compare takeoff and landing biomechanics between legs in patients who have undergone anterior cruciate ligament reconstruction. Kinematics and ground reaction forces were recorded as 13 patients performed the single-leg hop on each leg. Distance hopped, joint range of motion, peak joint kinetics and the peak total extensor moment were compared between legs during both takeoff and landing. Average hop distance ratio (involved/noninvolved) was 93 ± 4%. Compared to the noninvolved side, knee motion during takeoff on the involved side was significantly reduced (P = 0.008). Peak moments and powers on the involved side were lower at the knee and higher at the ankle and hip compared with the noninvolved side (Side by Joint P = 0.011; P = 0.003, respectively). The peak total extensor moment was not different between legs (P = 0.305) despite a decrease in knee moment and increases in ankle and hip moments (Side by Joint P = 0.015). During landing, knee motion was reduced (P = 0.043), and peak power absorbed was decreased at the knee and hip and increased at the ankle on the involved side compared to the noninvolved side (P = 0.003). The compensations by other joints may indicate protective adaptations to avoid overloading the reconstructed knee.

The effect of distal clavicle excision on in situ graft forces in coracoclavicular ligament reconstruction

BACKGROUND

Recently, some have suggested that the acromioclavicular articulation confers stability to the construct after coracoclavicular ligament reconstruction for acromioclavicular joint separation. Therefore, it has been suggested that distal clavicle excision should not be performed in this context to protect the graft during healing.

HYPOTHESIS

Sectioning the acromioclavicular ligaments would significantly increase in situ forces of a coracoclavicular ligament graft, whereas performing a distal clavicle resection would not further increase in situ graft forces.

DESIGN

Controlled laboratory study.

METHODS

A simulated coracoclavicular reconstruction was performed on 5 cadaveric shoulders. Static loads of 80 N and 210 N were applied directly to the clavicle in 5 directions: anterior, anterosuperior, superior, posterosuperior, and posterior. The in situ graft force was measured using a force transducer under 3 testing conditions: (1) intact acromioclavicular ligaments, (2) sectioned acromioclavicular ligaments, and (3) distal clavicle excision.

RESULTS

For both magnitudes of load, in all directions, in situ graft force with intact acromioclavicular ligaments was significantly less than that with sectioned acromioclavicular ligaments (P < .001). Distal clavicle excision did not further increase the in situ graft forces with load applied to the clavicle in an anterior, anterosuperior, or superior direction. However, in situ graft forces were increased with distal clavicle excision when the clavicle was loaded with 210 N in the posterosuperior direction (60.4 ± 6.3 N vs 52.5 ± 7.1 N; P = .048) and tended to be increased with posterior loading of the clavicle (71.8 ± 6.2 N vs 53.1 ± 8.8 N; P = .125).

CONCLUSION

Intact acromioclavicular ligaments protect the coracoclavicular reconstruction by decreasing the in situ graft force. The slight increase in the in situ graft force only in the posterosuperior and posterior direction after distal clavicle excision suggests only a marginal protective role of the acromioclavicular articulation. Further, the peak graft forces observed represent only a small fraction of the ultimate failure strength of the graft.

CLINICAL RELEVANCE

Distal clavicle excision can perhaps be safely performed in the context of coracoclavicular ligament reconstruction without subjecting the graft to detrimental in situ force. Although the acromioclavicular articulation serves only a marginal role in protecting the coracoclavicular ligament graft, reconstruction of the acromioclavicular ligaments may serve an important role in decreasing in situ graft force during healing.

Reliability of shoulder range of motion comparing a goniometer to a digital level

The clinical use of digital levels, for joint measurement, may be a viable alternative to standard goniometry. The purpose of this study was to determine the intra- and intertester reliability of a construction grade digital level compared to the standard universal goniometer for measurements for active assisted shoulder range of motion (ROM). Two experienced physical therapists measured shoulder flexion, external rotation (ER), and internal rotation (IR) ROM bilaterally, on two different occasions, in 20 patients (9 males, 11 females, 18-79 years old) with unilateral shoulder pathology, using a goniometer and a digital level. Relative reliability was assessed by using intraclass correlation coefficients (ICC), and absolute reliability was assessed by using 95% limits of agreement (LOA). Intratester ICCs ranged from 0.91 to 0.99, and LOA ranged from 3 degrees to 9 degrees for measurements made with the goniometer and digital level. Intertester ICCs ranged from 0.31 to 0.95, and LOA ranged from 6 degrees to 25 degrees . For the comparison of goniometric vs. digital level ROM, ICCs ranged from 0.71 to 0.98. ER and IR ROM were 3-5 degrees greater for the digital level than the goniometer (p < 0.01). Goniometric vs. digital level LOA ranged from 6 degrees to 11 degrees for shoulder flexion. Both measurement techniques had excellent intratester reliability, but for intertester reliability ICCs were 20% lower and LOA were 2.3 times higher than intratester values. Reliability estimates were similar between the digital level and the goniometer. However, because glenohumeral rotation was 3-5 degrees greater for the digital level than the goniometer (systematic error), the two methods cannot be used interchangeably. On the basis of the average intratester LOA for the goniometer and the digital level, a change of 6-11 degrees is needed to be certain that true change has occurred. For comparison of measures made by two different therapists, a change is of 15 degrees is required to be certain a true change has occurred. A digital level can be used to reliably measure shoulder ROM but should not be used interchangeably with a standard goniometer.

Addition of isolated wrist extensor eccentric exercise to standard treatment for chronic lateral epicondylosis: a prospective randomized trial

BACKGROUND

Isokinetic eccentric training of the wrist extensors has recently been shown to be effective in treating chronic lateral epicondylosis. However, isokinetic dynamometry is not widely available or practical for daily exercise prescription. Therefore, the objective of this study was to assess the efficacy of a novel eccentric wrist extensor exercise added to standard treatment for chronic lateral epicondylosis.

MATERIALS AND METHODS

Twenty-one patients with chronic unilateral lateral epicondylosis were randomized into an eccentric training group (n = 11, 6 men, 5 women; age 47 +/- 2 yr) and a Standard Treatment Group (n = 10, 4 men, 6 women; age 51 +/- 4 yr). DASH questionnaire, VAS, tenderness measurement, and wrist and middle finger extension were recorded at baseline and after the treatment period.

RESULTS

Groups did not differ in terms of duration of symptoms (Eccentric 6 +/- 2 mo vs Standard 8 +/- 3 mos., P = .7), number of physical therapy visits (9 +/- 2 vs 10 +/- 2, P = .81) or duration of treatment (7.2 +/- 0.8 wk vs 7.0 +/- 0.6 wk, P = .69). Improvements in all dependent variables were greater for the Eccentric Group versus the Standard Treatment Group (percent improvement reported): DASH 76% vs 13%, P = .01; VAS 81% vs 22%, P = .002, tenderness 71% vs 5%, P = .003; strength (wrist and middle finger extension combined) 79% vs 15%, P = .011.

DISCUSSION

All outcome measures for chronic lateral epicondylosis were markedly improved with the addition of an eccentric wrist extensor exercise to standard physical therapy. This novel exercise, using an inexpensive rubber bar, provides a practical means of adding isolated eccentric training to the treatment of chronic lateral epicondylosis.

Electromyographic activity of selected scapular stabilizers during glenohumeral internal and external rotation contractions

HYPOTHESIS

An important synergistic relationship exists between the scapular stabilizers and the glenohumeral rotators. Information on the relative contribution of the scapular stabilizers to glenohumeral rotation would be useful for exercise prescription for overhead athletes and for patients with shoulder pathology. We hypothesized that the scapular stabilizers would be highly active during both maximal and submaximal internal and external rotation.

MATERIALS AND METHODS

Eight healthy male volunteers (16 shoulders) performed internal and external glenohumeral rotation testing at maximal and submaximal intensities. They also performed a scapular retraction rowing exercise at maximal and submaximal levels. Electromyographic (EMG) signals were recorded from the infraspinatus, pectoralis major, serratus anterior, and middle trapezius. Values were compared among muscle groups, among individual muscles at different intensity levels, and among individual muscles at different points in the arc of motion.

RESULTS

For submaximal glenohumeral internal rotation, activity in the scapular stabilizers was not different (P = .1-.83) from activity in the internal rotator throughout the range of motion. For the initial two-thirds of maximal internal rotation, middle trapezius activity and pectoralis major activity were higher (P < .05) than serratus anterior activity. For submaximal external rotation, activity in the scapular stabilizers during the middle phase of the motion was higher (P < .05) than activity in the external rotators. For maximal external rotation these differences were present throughout the motion with middle trapezius activity exceeding 100% maximal voluntary contraction.

CONCLUSIONS

The scapular stabilizers functioned at a similar or higher intensity than the glenohumeral rotators during internal and external rotation. This highlights the importance of training the scapular stabilizers in upper extremity athletes and in patients with shoulder pathology.

The role of neural tension in hamstring flexibility

Resistance to stretch, electromyographic (EMG) response to stretch, stretch discomfort and maximum range of motion (ROM) were measured during passive hamstring stretches performed in the slump test position (neural tension stretch) and in the upright position (neutral stretch) in eight healthy subjects. Stretches were performed on an isokinetic dynamometer at 5°/s with the test thigh flexed 40° above the horizontal, and the seat back at 90° to the horizontal. Surface EMG signals were recorded from the medial and lateral hamstrings during stretches. Knees were passively extended to maximum stretch tolerance with test order (neural tension vs neutral) alternated between legs. For neural tension stretches, the cervical and thoracic spine were manually flexed. Maximum ROM was 8° less for the neural tension stretch vs the neutral stretch (P<0.01). Resistance to stretch was 14-15% higher for the neural tension stretch vs the neutral stretch (P<0.001) at common joint angles in the final third of ROM. Stretch discomfort and EMG response were unaffected by neural tension. In conclusion, an increased passive resistance to stretch with the addition of neural tension during passive hamstring stretch despite no change in the EMG response indicates that passive extensibility of neural tissues can limit hamstring flexibility.

Correction of posterior shoulder tightness is associated with symptom resolution in patients with internal impingement

BACKGROUND

Glenohumeral internal rotation deficit (GIRD) and posterior shoulder tightness have been linked to internal impingement.

PURPOSE

To determine if improvements in GIRD and/or decreased posterior shoulder tightness are associated with a resolution of symptoms.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Passive internal rotation and external rotation (ER) range of motion (ROM) at 90 degrees of shoulder abduction and posterior shoulder tightness (cross-chest adduction in side lying) were assessed in 22 patients with internal impingement (11 men, 11 women; age 41 +/- 13 years). Treatment involved stretching and mobilization of the posterior shoulder. The Simple Shoulder Test (SST) was administered on initial evaluation and discharge. Changes in GIRD, ER ROM, and posterior shoulder tightness were compared between patients with complete resolution of symptoms versus patients with residual symptoms using independent t tests.

RESULTS

Patients had significant GIRD (35 degrees), loss of ER ROM (23 degrees), and posterior shoulder tightness (35 degrees) on initial evaluation (all P < .01). Physical therapy (7 +/- 2 weeks; range, 3-12 weeks) improved GIRD (26 degrees +/- 14 degrees; P < .01), ER ROM loss (14 degrees +/- 20 degrees), and posterior shoulder tightness (27 degrees +/-19 degrees). The SST improved from 5 +/- 3 to 11 +/- 1 (P < .01). A greater improvement in posterior shoulder tightness was seen in patients with complete resolution of symptoms (n = 12) compared with patients with residual symptoms (35 degrees vs 18 degrees; P < .05). Improvements in GIRD and ER ROM loss were not different between groups (GIRD, 25 degrees vs 28 degrees, P = .57; ER ROM, 14 degrees vs 15 degrees, P = .84).

CONCLUSION

Resolution of symptoms after physical therapy treatment for internal impingement was related to correction of posterior shoulder tightness but not correction of GIRD.

To stretch or not to stretch: the role of stretching in injury prevention and performance

Stretching is commonly practiced before sports participation; however, effects on subsequent performance and injury prevention are not well understood. There is an abundance of literature demonstrating that a single bout of stretching acutely impairs muscle strength, with a lesser effect on power. The extent to which these effects are apparent when stretching is combined with other aspects of a pre-participation warm-up, such as practice drills and low intensity dynamic exercises, is not known. With respect to the effect of pre-participation stretching on injury prevention a limited number of studies of varying quality have shown mixed results. A general consensus is that stretching in addition to warm-up does not affect the incidence of overuse injuries. There is evidence that pre-participation stretching reduces the incidence of muscle strains but there is clearly a need for further work. Future prospective randomized studies should use stretching interventions that are effective at decreasing passive resistance to stretch and assess effects on subsequent injury incidence in sports with a high prevalence of muscle strains.

Oversized young athletes: a weighty concern

The prevalence of overweight and obesity in children and adolescents is increasing worldwide, with a corresponding decline in physical fitness and general physical activity level. Overweight and obese adolescents are more than twice as likely to be injured in sports and other physical activities compared with non-overweight and non-obese adolescents. Obese adolescent athletes are more than three times as likely to sustain an ankle sprain compared with normal weight adolescent athletes. At the societal level, promoting physical activity for children and improving dietary habits are key strategies for lowering the prevalence of overweight and obesity. The increased risk of injury associated with being overweight or obese may in part be due to low physical activity level. Promotion of physical activity for children can provide neuromuscular training that may be beneficial in decreasing injury risk associated with general play and sports participation. For lower-extremity injuries, specific neuromuscular training interventions, such as balance training, have great potential in reversing the increased injury risk associated with overweight and obesity. Finally, the injured overweight young athlete may have a more prolonged recovery period than non-overweight young athletes. Early aggressive treatment of swelling with physical modalities, prolonged non-weight bearing, limited period of immobilisation and regular repetitive passive joint motion are indicated for the overweight young athlete with a lower-extremity joint injury.

Effect of a tart cherry juice blend on exercise-induced muscle damage in horses

OBJECTIVE

To evaluate whether administering a tart cherry juice blend (TCJB) prior to exercise would reduce skeletal and cardiac muscle damage by decreasing the inflammatory and oxidative stress response to exercise in horses.

ANIMALS

6 horses.

PROCEDURES

Horses were randomly allocated into 2 groups in a crossover study with a 2-week washout period and orally administered either TCJB or a placebo solution (1.42 L, twice daily) in a double-masked protocol for 2 weeks prior to a stepwise incremental exercise protocol. Horses were tested for serum activities of creatine kinase and aspartate aminotransferase (AST) and concentrations of cardiac troponin I (cTnI), thiobarbituric acid reactive substances (TBARS; an indicator of oxidative stress), and serum amyloid A (SAA; an indicator of inflammation). To ensure that treatment would not result in positive results of an equine drug-screening protocol, serum samples obtained from each horse prior to and after 2 weeks of administration of TCJB or the placebo solution were tested.

RESULTS

All horses had negative results of drug screening at both sample times. The exercise protocol resulted in a significant increase in TBARS concentration, SAA concentration, and serum AST activity in all horses. Administration of TCJB or placebo solution was not associated with an effect on malondialdehyde or SAA concentrations. However, administration of TCJB was associated with less serum activity of AST, compared with administration of placebo solution.

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of TCJB may diminish muscle damage induced by exercise.