Shoulder and Scapular Muscle Activity During Low and High Plank Variations With Different Body-Weight-Bearing Statuses.

ABSTRACT: Can, EN, Harput, G, and Turgut, E. Shoulder and scapular muscle activity during low and high plank variations with different body-weight-bearing statuses. J Strength Cond Res 38(2): 245-252, 2024-This study investigated the activation levels and activation ratios of shoulder and scapular muscles during low plank (LP) and high plank (HP) variations, with varying levels of body-mass support, including 4-point, 3-pod, and 2-point body-weight-bearing (BWB) statuses. The study was conducted with 21 healthy men (mean ± SD , 26 ± 6.5 years of age and 24.4 ± 2.4 kg·m -2 BMI). Ten different plank exercises were performed in a mixed order by changing elbow joint positions (LP and HP) and BWB statuses (2-point, 3-pod, and 4-point). Activation levels of the lower trapezius (LT), middle trapezius (MT), upper trapezius (UT), biceps brachii, triceps brachii, infraspinatus, and serratus anterior (SA) muscles were assessed with a surface electromyography device. Results of this study showed that elbow position changes resulted in higher LT ( p = 0.01) and TB ( p = 0.001) activation in HP exercises. In general, it was observed that an increase in BWB status was effective in increasing activation for the scapula and shoulder girdle muscles. The ratios of the UT muscle to the SA, LT, and MT muscles were less than 1 during side plank, bird dog, front reach, shoulder taps, and plank with shoulder external rotation exercises. High plank with toe touch exercise resulted in a marked increase in the UT activation. Therefore, it was concluded plank variations alter activation levels and activation ratios of shoulder and scapular muscles. Plank exercises may be used in shoulder rehabilitation and the progression in plank variations can be achieved by changing elbow position and BWB status based on individual requirements.

Case-based report of graded motor imagery experience in traumatic brachial plexus injury: The art of moving without moving.

BACKGROUND: We reported a 24-year-old woman who sustained multiple upper limb injuries after a traffic accident in March 2017. She sustained a C7-T1 brachial plexus injury and radial nerve injury on the left side diagnosed in November 2017. The patient underwent radial nerve reconstruction. The patient began her comprehensive therapy program in January 2018. PURPOSE: To describe the use of graded motor imagery (GMI) and outcomes after traumatic brachial plexus palsy. We presented changes in electromyographic (EMG) activity of target muscles during task execution and functional status following 10-session GMI therapy. STUDY DESIGN: Case report. METHODS: The program included 4 sessions of motor imagery and 6 sessions of a combination of motor imagery and mirror therapy. RESULTS: The patient successfully participated in the program with reported improvements in EMG activity, functional status, emotional well-being, and body awareness. CONCLUSIONS: GMI therapy appears to have peripheral motor effects, including altered surface EMG activity and contributes to a favorable outcome in the functional level of the affected arm. An improved emotional state and awareness of the affected hand could have a positive effect on function. Future long-term randomized controlled trials are needed to investigate the cumulative peripheral effects of treatment of graded motor imagery and the effects of variables mediating its effects on functional performance in patients with nerve injury.

Voluntary Contraction of the Abdominal Muscles During Shoulder Exercises Increases Scapular Muscle Activation: A Critically Appraised Topic.

CLINICAL SCENARIO: The fascial relationship between scapular muscles and abdominal muscles has been documented from previous studies. However, it is not yet clear whether voluntary abdominal contraction has a beneficial effect on scapular muscle activity during shoulder exercises. CLINICAL QUESTION: Do scapulothoracic muscle activation levels increase if shoulder exercises are performed with voluntary abdominal activation? Summary of Key Finding: After the literature review, 4 cross-sectional studies met the inclusion criteria and were included in this critically appraised topic. CLINICAL BOTTOM LINE: There is moderate evidence to support dynamic shoulder exercises with voluntary abdominal contraction can increase trapezius and serratus anterior muscle activation level in asymptomatic shoulders. Strength and Recommendation: Findings from 4 cross-sectional trials indicate that there is moderate evidence supporting that dynamic shoulder exercises performed with voluntary abdominal contraction can increase scapular muscle activity.

Voluntary Contraction of the Abdominal Muscles Increases Hip Muscle Activation During Lower-Extremity Exercises: A Critically Appraised Topic.

CLINICAL SCENARIO: Existing studies have posited that incorporating abdominal enhancement techniques during lower-extremity exercises might mitigate compensatory pelvic motions and enhance the engagement of specific hip muscles. CLINICAL QUESTION: Does performing lower-extremity exercises with abdominal enhancement techniques increase hip muscle activation levels in healthy individuals? Summary of Key Finding: After the literature review, 4 cross-sectional studies met the inclusion criteria and were included in this critically appraised topic. CLINICAL BOTTOM LINE: There is moderate evidence to support that prone hip extension with abdominal enhancement may increase gluteus maximus and hamstring muscle activity. Gluteus medius activity may not be affected by abdominal enhancement during hip abduction exercises. Strength and Recommendation: The collective findings from the 4 cross-sectional trials indicate that the incorporation of abdominal enhancement techniques during lower-extremity exercises may have the potential to enhance targeted muscle activation levels in healthy individuals. Further research is recommended to establish more robust conclusions.

Weight-Bearing Exercises on Slideboard Increase Quadriceps and Hamstring Activation Levels and Improve Hip- and Knee-Flexion Angles in Physically Active Individuals.

CONTEXT: Slideboards are commonly used in exercise programs, but there is limited information about how they affect muscle activities during exercise. We aim to compare the activation levels of quadriceps and hamstring muscles and hip- and knee-flexion angles during lunge and single-leg squat exercises between normal ground and slideboard in physically active individuals. DESIGN: Cross-sectional study. METHODS: Thirty healthy individuals (age: 23.83 [2.84] y, body mass index: 21.75 [1.72] kg/m2) were included in the study. Surface electromyography was used to measure vastus medialis, vastus lateralis, biceps femoris, and semitendinosus activation levels during reaching and returning phases of the forward, lateral, and back lunges and squats that were performed on the normal ground and slideboard. Exercises were performed at a slow pace (60 beats/min). Hip- and knee-flexion angles during the exercises were evaluated by using 2-dimensional motion analysis. Repeated measures of analysis of variance were used for statistical analysis. RESULTS: Vastus medialis and vastus lateralis activation levels were greater during reaching and returning phases of the exercises on slideboard compared with normal ground (P < .05). However, semitendinosus and biceps femoris activity were greater only during the returning phase of the forward lunge (P < .001) and the returning phase of the back squat (P = .002, P = .009, respectively). Hip-to-knee flexion ratios were closer to 1 when the forward lunge (P < .001), back lunge (P = .004), and forward squat (P = .001) exercises were performed on a slideboard. CONCLUSION: In exercise programs that target the quadriceps and hamstring muscles, slideboards can be effectively used in exercise progressions as they can increase muscle activity. Moreover, squat and lunge exercises on slideboard with a slow pace may also be helpful for improving the balance between hip- and knee-flexion angles.

Altered Ankle Muscle Activation at 2-Year Post Achilles Tendon Repair: An Age, Gender, and Activity Level-Matched Comparison With Healthy Subjects.

CONTEXT: The study purpose was to compare the ankle muscle activation and dynamic ankle joint stability of subjects who underwent endoscopy-assisted Achilles tendon repair (ATR; at ≥ 2 y postsurgery) with age, gender, and activity level-matched healthy control group subjects. DESIGN: Prospective, cross-sectional study. All functional tests were performed on the involved ankle of the ATR group, and at the matched side of healthy age, gender, and activity-level control group subjects. METHODS: Fifteen men in each group were evaluated for medial and lateral gastrocnemius, soleus, tibialis anterior, and peroneus longus muscle activation during modified star excursion balance test and heel-rise test performance. The weight-bearing lunge test (ankle dorsiflexion) and heel-rise test distance (ankle plantar flexion) also determined weight-bearing, active ankle mobility magnitudes. The Achilles Tendon Total Rupture Score and Foot and Ankle Outcome Score provided patient-reported outcome perceptions specific to Achilles tendon rupture and comprehensive foot and ankle symptoms and function, respectively. RESULTS: Medial (P = .005) and lateral (P = .012) gastrocnemius displayed greater activation amplitudes in the ATR group during the star excursion balance test, and peroneus longus displayed greater activation amplitudes during the heel-rise test (P = .006). The star excursion balance test reach distance was comparable between groups. Active weight-bearing ankle plantar flexion (heel-rise test) and dorsiflexion (weight-bearing lunge test) mobility magnitudes were lower in the ATR group. CONCLUSIONS: Subjects who underwent endoscopy-assisted percutaneous ATR had reduced active weight-bearing ankle dorsiflexion and plantar flexion mobility magnitudes and greater gastrocnemius and peroneus longus neuromuscular activation when performing the same tasks as healthy control group subjects. As surgical approaches evolve to less invasive, soft tissue preserving methods with less tissue morbidity and faster healing, rehabilitation approaches may likewise need to evolve. LEVEL OF EVIDENCE: Level III.

Knowledge and awareness of anterior cruciate ligament injury among Turkish professional athletes: an online survey.

The purpose of this study was to assess the awareness and knowledge of professional team sport athletes about ACL injuries, injury prevention programs, and the return to sports after ACL injuries. A total of 419 athletes representing soccer, basketball, volleyball and handball sports were included in the study. We utilized a 15-item self-report survey to assess the awareness of athletes about ACL injury, ACL injury prevention program, and return to sport after ACL injuries. Male and soccer players participated in prevention programs more than female athletes (p = 0.001). Participation in prevention programs was significantly higher in the ≥ 18 years old group than in the < 18 years old group (p = 0.040). Participants who were informed about ACL injuries were 8.4 times more likely to participate in the ACL injuries prevention program than others (OR: 8.38, 95% CI: 3.823-18.376, p < 0.001). The majority of participants believed that return to sport after ACL injury takes 6 months and 81.4% of them thought that it is not possible to do sport without an ACL. This study revealed that the awareness and performance of ACL prevention training programs among professional team sport athletes were insufficient. The athletes' knowledge regarding return to sports after ACL injuries was also inadequate. Improving athletes' knowledge of ACL injuries may lead to increased participation in ACL injury prevention programs. Thus, the provision of tailored educational interventions to athletes could potentially enhance their awareness and understanding of ACL injuries, consequently contributing towards the prevention of such injuries.

Sports activity level after ACL reconstruction is predicted by vastus medialis or vastus medialis obliquus thickness, single leg triple hop distance or 6-m timed hop, and quality of life score.

PURPOSE: Recovery after anterior cruciate ligament reconstruction (ACLR) may take > 2 years, and younger athletes have higher re-injury risk. The purpose of this prospective longitudinal study was to determine how the early to mid-term Tegner Activity Level Scale (TALS) scores of athletically active males ≥ 2 years post-ACLR follow-up was predicted by bilateral isokinetic knee extensor and flexor torque, quadriceps femoris thickness, single leg hop test performance, and self-reported knee function (Knee Injury and Osteoarthritis Outcome Score (KOOS); International Knee Documentation Committee (IKDC) Subjective Assessment score). METHODS: After ACLR with a hamstring tendon autograft and safely returning to sports at least twice weekly, 23 men (18.4 ± 3.5 years of age) were evaluated at final follow-up (mean = 4.5, range = 2-7 years). Exploratory forward stepwise multiple regression was used to determine the relationship between independent surgical and non-surgical lower limb variables peak concentric isokinetic knee extensor-flexor torque at 60°/sec and 180°/sec, quadriceps femoris muscle thickness, single leg hop test profile results, KOOS subscale scores, IKDC Subjective Assessment scores, and time post-ACLR on TALS scores at final follow-up. RESULTS: Subject TALS scores were predicted by KOOS quality of life subscale score, surgical limb vastus medialis obliquus (VMO) thickness, and surgical limb single leg triple hop for distance (SLTHD) performance. Subject TALS scores were also predicted by KOOS quality of life subscale score, non-surgical limb vastus medialis (VM) thickness, and non-surgical limb 6 m single leg timed hop (6MSLTH) performance. CONCLUSION: TALS scores were influenced differently by surgical and non-surgical lower extremity factors. At ≥ 2 years post-ACLR, ultrasound VM and VMO thickness measurements, single leg hop tests that challenge knee extensor function, and self-reported quality of life measurements predicted sports activity levels. The SLTHD test may be better than the 6MSLTH for predicting long-term surgical limb function.

Effects of Whole-Body Vibration Training on Knee Muscle Strength After Anterior Cruciate Ligament Reconstruction: A Critically Appraised Topic.

Clinical Scenario: Knee muscle strength weakness after anterior cruciate ligament (ACL) reconstruction is the most commonly seen impairment. Whole-body vibration (WBV) training has been shown to improve muscle strength in both healthy and injured individuals. However, it is not clear yet if WBV training has a beneficial effect in knee muscle strength recovery after ACL reconstruction. Clinical Question: Is adding WBV training to conventional rehabilitation more effective than conventional rehabilitation at improving quadriceps and hamstring muscles strength in individuals who have undergone ACL reconstruction? Summary of Key Findings: After the literature was reviewed, 4 randomized controlled trials met the inclusion criteria and were included in this critically appraised topic. Clinical Bottom Line: There is moderate- to high-quality evidence to support that adding WBV to conventional rehabilitation programs can result in better improvement in knee muscle strength after ACL reconstruction. Strength of Recommendation: Findings from 4 randomized controlled trials indicate that there is level B evidence supporting that WBV is effective for knee muscle strength recovery in patients who had undergone ACL reconstruction.

Translation, cross-cultural adaptation, and validation of the Turkish version of the shoulder instability-return to sport (SI-RSI) after injury scale.

To translate and culturally adapt the shoulder instability-return to sport after injury (SI-RSI) scale into Turkish (SI-RSI-Tr) and examine the psychometric properties of the Turkish version of athletes following a traumatic shoulder instability. The SI-RSI was translated into Turkish using Beaton guidelines. Sixty-nine patients with shoulder instability completed the translated SI-RSI, Western Ontario Shoulder Instability Index (WOSI), the Tampa Scale of Kinesiophobia (TSK), and the Walch-Duplay Scores. We analysed the internal consistency, agreement, reliability, and validity of the SI-RSI-Tr. The SI-RSI-Tr demonstrated excellent internal consistency (Cronbach's alpha = 0.92), test-retest reliability (ICC = 0.95), and feasibility with no ceiling or floor effect. SI-RSI-Tr correlated with WOSI total score (r = -0.824, p < 0.001), its subscales: WOSI-physical (r = -0.683, p < 0.001), WOSI-sports (r = -0.832, p < 0.001), WOSI-lifestyle (r = -0.739, p < 0.001), and WOSI-emotions (r = -0.734, p < 0.001) respectively), Walch-Duplay (r = 0.840, p < 0.001) and TSK (r = -0.828, p < 0.001) scores. The Turkish SI-RSI is a reliable, internally consistent, and valid tool for athletes with shoulder instability. Researchers and clinicians could safely use the SIRSI-Tr to evaluate the shoulder-specific psychological factors on return to sports following an episode of shoulder instability.

Higher Body Mass Index Adversely Affects Knee Function After Anterior Cruciate Ligament Reconstruction in Individuals Who Are Recreationally Active.

OBJECTIVE: Our aim was to investigate the effect of body mass index (BMI) levels on quadriceps and hamstring strength and functional outcomes up to 6 months after anterior cruciate ligament reconstruction (ACLR) with hamstring tendon autograft (HTG). DESIGN: Prospective, controlled study. SETTING: University clinical laboratory. PATIENTS: Ninety-one participants who had undergone unilateral ACLR with HTG were divided into 2 groups according to their BMI. The participants whose BMI were between 18.5 and 24.9 kg/m were included in group 1 (n = 50, age: 27.2 ± 6.7 years, BMI: 22.3 ± 1.6 kg/m) and those whose BMI > 24.9 kg/m were included in group 2 (n = 41, age: 30.2 ± 6.9 years, BMI: 28.0 ± 2.4 kg/m). INTERVENTIONS: Quadriceps and hamstring strength, functional performance including hop, jump, and balance performance, and IKDC score. MAIN OUTCOME MEASURES: Maximum voluntary isometric contraction of the quadriceps and hamstring muscles and the body mass were measured at 1, 3, and 6 months after surgery. Absolute peak torques and normalized peak torques to body weight for both limbs were recorded. Functional outcomes were evaluated at 6 months after surgery. RESULTS: Normalized quadriceps strength improvement was lower in group 2 when compared with group 1 (F(2,178) = 6.23, P = 0.003). Group 2 also demonstrated lower scores in functional performance (P < 0.05). Normalized hamstring and absolute quadriceps and hamstring strength improvement was not affected by higher BMI level (P > 0.05). CONCLUSIONS: Higher BMI levels adversely affect quadriceps strength capacity and performance in patients who have undergone ACLR with HTG. Clinicians should consider BMI levels of patients when assessing and targeting muscle recovery because it could negatively affect the success of the ACLR rehabilitation.

Quadriceps tendon autograft ACL reconstructed subjects overshoot target knee extension angle during active proprioception testing.

PURPOSE: To compare the active joint position sense (JPS), muscle strength, and knee functions in individuals who had anterior cruciate ligament (ACL) reconstruction with quadriceps tendon autograft, hamstring tendon autograft, tibialis anterior allograft and healthy individuals. It was hypothesized that when compared to an age and gender-matched healthy control group, subjects who were post-ACL reconstruction would display impaired active joint position sense, knee extensor and flexor strength symmetry and knee function at 1 year post-surgery. A secondary hypothesis was that differences would exist between the quadriceps tendon autograft, hamstring tendon autograft and tibialis anterior allograft groups. METHODS: Sixty-seven patients with ACL reconstruction and 20 healthy individuals were included. Active JPS reproduction was measured at 15°, 45° and 75° of knee flexion. International Knee Documentation Committee (IKDC) subjective score and one-leg hop test were used to assess the functional status of the patients. RESULTS: The JPS detection was different at the 15° target angle between groups (F3.86 = 24.56, p < 0.001). A significantly higher proportion of quadriceps tendon autograft group patients failed to identify the 15° active JPS assessment position compared to the other groups (p < 0.0001). The quadriceps index was lower in patients compared to healthy individuals (p < 0.001), while the hamstring index was similar (n.s.). The knee functional outcomes were similar between ACL reconstructed groups and healthy controls (n.s.). CONCLUSION: Knee proprioception deficits and impaired muscle strength were evident among patients at a mean 13.5 months post-ACL reconstruction compared with healthy controls. Patients who underwent ACL reconstruction using a quadriceps tendon autograft may be more likely to actively over-estimate knee position near terminal extension. Physiotherapists may need to focus greater attention on terminal knee extension proprioceptive awareness among this patient group. LEVEL OF EVIDENCE: III.

Does scapular corrective taping alter periscapular muscle activity and 3-dimensional scapular kinematics? A systematic review.

STUDY DESIGN: This is a systematic review. INTRODUCTION: Scapular taping is widely used in the management of scapular dysfunction. However, its effects on the scapular kinematics and the electromyography (EMG) activity of the periscapular muscles are not clear. PURPOSE OF THE STUDY: The purpose of the study was to systematically review the current literature to examine whether scapular corrective taping alters the EMG activity of the periscapular muscles and the 3-dimensional scapular kinematics. METHOD: MEDLINE and Web of Science databases were searched using specific mesh terms up to April 2018. A hand search was also conducted on the reference list of the included articles. A total of 157 studies were identified, and they were further analyzed for the eligibility to the systematic review. Studies that investigated the effects of scapular corrective taping on the EMG activity of the periscapular muscles and on the 3-dimensional scapular kinematics on patients with shoulder problems or asymptomatic subjects were eligible for the systematic review. The Cochrane Effective Practice and Organization of Care criteria were modified and used for the risk-of-bias assessment. RESULTS: Eleven articles met the inclusion criteria and were included in the systematic review. Five studies investigated the effects of corrective taping on the scapular kinematics and 8 studies reported the effects of corrective taping on the EMG activity of the periscapular muscles. There was an agreement among the studies that scapular upward rotation is increased with the corrective taping, while there are inconsistent results concerning the scapular external rotation and posterior tilt. In addition, studies mostly reported that corrective taping decreases the activity of the upper trapezius, while it has conflicting effects on the activity patterns of other periscapular muscles. DISCUSSION: Scapular corrective taping was found to increase the scapular upward rotation; however, its effects on scapular external rotation and posterior tilt are controversial. It was also found that corrective taping might decrease the EMG activity of the upper trapezius, while it had no effects on the activity of lower trapezius, and its effects on other periscapular muscles were controversial. CONCLUSION: The results of the studies indicated that scapular corrective taping might alter the 3-dimensional scapular kinematics, while there are controversies about the effects of corrective taping on the EMG activity of the periscapular muscles. Further studies are needed to clarify the conflicts.

Quadriceps and Hamstring Strength Symmetry After Anterior Cruciate Ligament Reconstruction: A Prospective Study.

OBJECTIVES: To evaluate change in involved and uninvolved quadriceps and hamstring strength and limb symmetry indices (LSI) in regular intervals over the first 6 months following anterior cruciate ligament reconstruction (ACLR). DESIGN: Prospective cohort study. PARTICIPANTS: Thirty-eight male participants (mean age: 24.2 [6.4] y, mean body mass index: 23.6 [4.2] kg/m2), who underwent ACLR were included. MAIN OUTCOME MEASURES: Isometric strength testing of the quadriceps and hamstring muscles was performed at 1, 2, 3, and 6 months after ACLR. Quadriceps and hamstring peak torques for each limb and LSI were calculated. Repeated-measures analysis of covariance and paired t tests were used to evaluate changes in strength over time and between limbs, respectively. RESULTS: Quadriceps and hamstring peak torques of the involved limb consistently increased between each time point from 1 to 6 months (P < .001 and P = .01, respectively), whereas the uninvolved limb values did not change after ACLR (P > .05). In addition, uninvolved limb peak torque values were higher than involved limb values at each time point after ACLR for both the quadriceps and hamstrings (all P < .01). At 6 months after ACLR, 28.9% of participants demonstrated LSI greater than 90% for quadriceps strength, 36.8% demonstrated LSI greater than 90% for hamstring strength, and 15.8% of participants demonstrated greater than 90% LSI for both quadriceps and hamstring strength. CONCLUSIONS: Participants demonstrated a consistent increase in quadriceps and hamstring strength of the involved limb, with no notable change in uninvolved limb strength over the 6 months after ACLR. However, at 6 months after ACLR, only approximately 16% of participants demonstrated both quadriceps and hamstring strength LSI greater than 90%, the typically recommended cutoff value for return to sport.

Electromyographic activity and kinematics of sit-to-stand in individuals with muscle disease.

OBJECTIVE: The aim of this study was to compare activation levels of rectus femoris, biceps femoris, tibialis anterior, and soleus muscles and biomechanical properties of individuals with muscle disease and healthy individuals during sit-to-stand. METHODS: Fifteen patients (11 muscular dystrophy, 4 myopathy) and 15 healthy individuals were included in the study. A Noraxon superficial electromyography device and high-speed cameras were used to evaluate muscle activations and biomechanical properties. RESULTS: There was a difference between the activation levels of bilateral rectus femoris, tibialis anterior, soleus, and right biceps femoris of patients and healthy subjects (p < 0.05). When groups were compared in terms of biomechanical properties, there was no difference in the range of motion during sit-to-stand (p > 0.05), but there was a difference in phase 1: flexion momentum phase, phase 3: extension phase, phase 4: stabilization phase, and total time of sit-to-stand (p < 0.05). CONCLUSION: We observed that individuals with muscle disease are able to stand up in a similar sit-to-stand pattern to healthy individuals with longer duration and higher muscle activation levels. Prolonged high muscle activation during functional activities may cause fatigue and muscle destruction in patients. For this reason, planning of exercise programs for appropriate muscles and phases will enable the patients to perform the activity of sit-to-stand more easily. Thus, patients will become more functional and independent in their daily lives with less effort.

Angle-specific knee muscle torques of ACL-reconstructed subjects and determinants of functional tests after reconstruction.

The purposes of this study were to analyse (a) if "angle-specific" (AS) flexor and extensor torques were different between ACL-reconstructed and uninvolved limbs, (b) the difference in peak torque occurrence angles for concentric and eccentric knee flexor and extensor torques between involved and uninvolved limbs and (c) if AS concentric and eccentric knee flexor and extensor torques are determinants of performance in the "single-leg hop test" (SLHT) and "vertical jump and reach test" (VJRT) in ACL-reconstructed legs. Twenty-seven male ACL-reconstructed volunteers were included in the study. Isokinetic knee muscle strength, SLHT and VJRT were performed 6 months after ACL reconstruction. No difference was found in extremity and knee joint angle interaction for concentric and eccentric flexor and extensor torques (p > 0.05). Peak torque occurrence angles were not different between involved and uninvolved limbs (p > 0.05). In involved extremities, concentric knee extensor strength at 90° was a determinant of SLHT performance (R2 = 0.403, p < 0.05), and concentric knee extensor strength at 60° was a determinant of VJRT (R2 = 0.224, p < 0.05). Assessment of AS concentric knee extensor strength at 60° and 90° might be important, because these were determinants of functional test performance.

Cross-education improves quadriceps strength recovery after ACL reconstruction: a randomized controlled trial.

PURPOSE: The aim of this study was to investigate the effects of concentric and eccentric cross-education (CE) on quadriceps strength and knee function recoveries after anterior cruciate ligament (ACL) reconstruction. METHODS: Forty-eight patients (age: 29.5 ± 6.8 years, body mass index: 26.1 ± 3.2 kg/m2) who had undergone ACL reconstruction with hamstring tendon autograft were included in the study. The patients were randomly divided into three groups when they reached four weeks post surgery: (1) concentric CE (n = 16); (2) eccentric CE (n = 16); and (3) control (n = 16). All groups followed the same post-surgical rehabilitation program for their reconstructed limb. Additionally, the two experimental groups followed eight weeks of isokinetic training for the uninjured knee at 60°/s for 3 days per week. Quadriceps maximum voluntary isometric strength (MVIC) was measured during the 4th week (pre-training), 12th week (post training), and 24th week post surgery. The single-leg hop distance and International Knee Documentary Committee (IKDC) scores were also evaluated during the 24th week post surgery. Analysis of variance was used for statistical analysis. RESULTS: Group-by-time interaction was significant for quadriceps MVICs for reconstructed and healthy limbs (p = 0.02). Quadriceps strength of both knees was greater in concentric and eccentric CE groups compared to control group during the 12th- and 24th weeks post surgery (p < 0.05). Strength gain was 28% and 31% in concentric and eccentric CE groups, respectively, when compared with the control group. Concentric and eccentric CE had similar effects on quadriceps strength recovery (n.s.). IKDC score, and single-leg hop distances were not significantly different among groups (n.s.). CONCLUSIONS: Concentric and eccentric quadricep strengthening of healthy limbs in early phases of ACL rehabilitation improved post-surgical quadriceps strength recovery of the reconstructed limb. CE should be integrated into ACL reconstruction rehabilitation, especially in the early rehabilitative phases to restore quadriceps strength. LEVEL OF EVIDENCE: Randomized controlled trial, Level I.

Relationship Between Middle Trapezius Muscle Activation and Acromiohumeral Distance Change During Shoulder Elevation With Scapular Retraction.

CONTEXT: The scapular retraction exercises are widely used among clinicians to balance the activity of the scapular muscles as well as the rotator cuff muscles in different shoulder abduction positions. OBJECTIVES: The aim of this study was to investigate the relationship between scapular (middle and upper trapezius) and shoulder muscles (middle deltoid and infraspinatus) activation level differences and acromiohumeral distance changes during shoulder abduction with scapular retraction. DESIGN: Cross-sectional study. SETTING: University research laboratory. PARTICIPANTS: Nineteen asymptomatic individuals were included (mean [SD]: age = 22.4 [1.8] y). MAIN OUTCOME MEASURE: The acromiohumeral distance was measured at 0° and 90° shoulder abduction when the scapula was in nonretracted and retracted position with ultrasound imaging. The relationship between muscle activation level changes and acromiohumeral distance difference was analyzed with the Pearson correlation test. RESULTS: Middle trapezius muscle activity change correlated with acromiohumeral distance difference (r = .55, P = .02) from 0° to 90° shoulder abduction when scapula was retracted. For both nonretracted and retracted scapular positions, no correlations were found between middle deltoid, infraspinatus, and upper trapezius muscle activity changes with acromiohumeral distance differences during shoulder abduction (P > .05). CONCLUSIONS: Active scapular retraction exercise, especially focusing on the middle trapezius muscle activation, seems to be an effective treatment option to optimize the acromiohumeral distance during shoulder abduction.

Short-Term Results of Flexor Hallucis Longus Transfer in Delayed and Neglected Achilles Tendon Repair.

Flexor hallucis longus (FHL) tendon transfer to the calcaneus in the repair of delayed or neglected Achilles tendon (AT) injuries is a viable and dynamic option. Nineteen patients (18 males, 1 female; mean age 47.4 ± 12.4, range 24 to 74, years; body mass index 27.5 ± 4.5, range 23.2 to 38.9, kg/m2; interval from injury to surgery 40.8 ± 11.6, range 28 to 60, days) with delayed or neglected repair of AT rupture were included in the present study. FHL transfer to the calcaneus through a single incision and repair of the defect with native tendon lengthening or a tendinous turndown flap was performed. American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot and hallux scale scores, balance and jump performance, ankle dorsiflexion range of motion, and lower extremity concentric and eccentric strength were evaluated 6 months postoperatively. Student's t test was used to compare the outcomes between the operated and nonoperated sides. AOFAS hindfoot and hallux scale scores were 93.83 and 86.9, respectively. No significant difference was found in vertical jump (p = .60), forward jump (p = .68), or balance performance (p > .05). However, less ankle dorsiflexion on the operated side was recorded compared with the nonoperated side (p = .008). Concentric/eccentric muscle strength between the operated and nonoperated side was similar (p > .05). The concentric strength of the operated side reached 92% and eccentric strength reached 101.7% of the nonoperated side's strength. All the patients were satisfied with their results and return to preinjury daily activities. AT repair of a delayed and neglected injury using FHL transfer to the calcaneus in a dynamic fashion provided excellent outcomes.