Inclinometers and Apps Are Better than Goniometers, Measuring Knee Extension Range of Motion in Anterior Cruciate Ligament Patients: Reliability and Minimal Detectable Change for the Three Devices.

Knee extension range of motion (ROM) measurement is important in patients with anterior cruciate ligament (ACL) injury. The main objective is to evaluate the reliability and the minimal detectable change (MDC) of three methods of measuring knee extension ROM in ACL patients. The three common goniometric devices were a universal goniometer, an inclinometer, and a smartphone app. During a single-visit, knee extension ROM was measured in both knees of 92 ACL-injured or -reconstructed patients by two testers blinded to the other's measures. Intrarater, interrater, and test-retest intraclass correlation coefficients (ICC2,1) were calculated. Intrarater ICC2,1 was excellent for the three devices ranging from 0.92 to 0.94, with the inclinometer yielding the best results (ICC2,1 = 0.94 [95% confidence interval, CI: 0.91-0.96]). Interrater ICC2,1, however, varied from 0.36 to 0.80. The inclinometer and the smartphone app yielded similar results 0.80 (95% CI: 0.71-0.86) and 0.79 (95% CI: 0.70-0.86), respectively, whereas the universal goniometer was 0.36 (95% CI: 0.17-0.53). Test-retest ICC2,1 for the inclinometer was 0.89 (95% CI: 0.84-0.93), 0.86 (95% CI: 0.79-0.91) for the app, and 0.83 (95% CI:0.74-0.89) for the goniometer. The intrarater, interrater, and test-retest MDC95 values ranged from 2.0 to 3.5, 3.7 to 10.4, and 2.6 to 5.4 degrees, respectively. The goniometer was the least reliable. The inclinometer is the recommended device due to its highest ICC scores among the three devices and ease of use.

Quadriceps and Hamstrings Activation Peaks Earlier as Athletes Repeatedly Hop, but There are Differences Depending on ACL Reconstruction Technique.

Background: After Anterior Cruciate Ligament Reconstruction (ACLR) athletes face the challenge of regaining their previous competitive level while avoiding re-injury and early knee joint cartilage degeneration. Quadriceps and hamstrings strength reductions and neuromuscular alterations potentially related to risk of re-injury are present after ACLR and relate to deficits in muscle activation. Design: Cross-sectional laboratory study. Purpose: To examine quadriceps and hamstrings muscle activation during repeated hops in healthy pivoting-sport athletes and those who had undergone ACLR (bone-tendon-bone and semitendinosus graft) who had met functional criteria allowing return to training. Methods: Surface electromyography (SEMG) was recorded from vastus medialis and lateralis and medial and lateral hamstrings bilaterally during 30 seconds' repeated hopping in male athletes on average eight months after ACLR surgery (5-12 months). All patients underwent hamstring (HS) (n=24) or bone-tendon-bone (BTB) reconstruction (n=20) and were compared to healthy controls (n=31). The SEMG signals were normalized to those obtained during maximal voluntary isometric contraction. Results: A significant time shift in peak muscle activation (earlier) was seen for: vastus medialis and vastus lateralis activation in the control group, in the BTB group's healthy (but not injured) leg and both legs of the HS group. A significant time shift in peak muscle activation was seen for lateral hamstrings (earlier) in all but the BTB group's injured leg and the medial hamstrings in the control group only. Lower peak activation levels of the vastus lateralis (p\<0.001) and vastus medialis (p\<0.001) were observed in the injured compared to healthy legs and lower peak lateral hamstrings activity (p\<0.009) in the injured leg compared to control leg. Decline in medial hamstring peak activation (p\<0.022) was observed between 1st and 3rd phase of the hop cycle in all groups. Conclusion: Repeated hop testing revealed quadriceps and hamstring activation differences within ACLR athletes, and compared to healthy controls, that would be missed with single hop tests. Level of evidence: 3.

Beware of the "Moving Target" - Uninvolved Limb Strength Increases to Exceed Preoperative Values During Rehabilitation After ACL Reconstruction in Male Professional and Recreational Athletes.

OBJECTIVE: To describe the changes in quadriceps and hamstrings muscle strength in the uninvolved limb of male professional and recreational athletes during rehabilitation after anterior cruciate ligament reconstruction (ACLR) and compare to preoperative strength values. DESIGN: Prospective longitudinal study. METHODS: During rehabilitation, 665 participants who underwent unilateral ACLR performed a strength test preoperatively and every 6 weeks after surgery for up to 9 months. Isokinetic quadriceps and hamstrings strength of the uninvolved limb were measured at an angular velocity of 60°/s and normalized to body weight (N·m/kg). RESULTS: Quadriceps and hamstrings strength of the uninvolved limb gradually increased during rehabilitation until 6 months post-ACLR, and plateaued thereafter. Postoperative quadriceps' strength significantly exceeded preoperative values by 3 months for professional (2.99 N·m/kg; 95% confidence interval [CI]: 2.93, 3.04; P = .007) and by 6 months for recreational athletes (2.77 N·m/kg; 95% CI: 2.71, 2.83; P<.001), and hamstrings exceeded presurgery levels by 4.5 months (1.71 N·m/kg; 95% CI: 1.67, 1.74; P<.001 and 1.43 N·m/kg; 95% CI: 1.40, 1.46; P = .002, professional and recreational athletes respectively). CONCLUSION: In male professional and recreational athletes, uninvolved limb quadriceps and hamstrings strength gradually improved after ACLR, until 6 months after surgery. The uninvolved limb's strength may present as a "moving target" that requires consistent monitoring during rehabilitation. J Orthop Sports Phys Ther 2024;54(4):1-9. Epub 14 December 2023. doi:10.2519/jospt.2023.11961.

Lower Patellofemoral Joint Contact Force During Side-Step Cutting After Return-to-Sports Clearance Following Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Low patellofemoral joint (PFJ) contact force has been associated with PFJ osteoarthritis. Quadriceps force and knee flexion angles, which are typically altered after an anterior cruciate ligament reconstruction (ACLR), primarily influence PFJ contact forces. It is still inconclusive whether differences in PFJ contact forces are present during high knee flexion tasks such as side-step cutting after clearance to return to sports (RTS) after ACLR. PURPOSE: To explore PFJ contact forces in the ACLR limb and compare them with those of the contralateral and control limbs during side-step cutting tasks after clearance to RTS. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 26 male athletes with ACLR who were previously cleared to RTS were matched with 23 healthy men serving as the control group. Three-dimensional motion capture and force plate data were collected while both groups performed anticipated side-step cutting tasks. Joint kinematics, kinetics, muscle forces, and PFJ contact forces were calculated using musculoskeletal modeling. RESULTS: Peak PFJ force was lower in the ACLR limbs compared with the contralateral limbs (mean difference [MD], 5.89 body weight [BW]; 95% CI, 4.7-7.1 BW; P < .001) and the control limbs (MD, 4.44 BW; 95% CI, 2.1-6.8 BW; P < .001). During peak PFJ force, knee flexion angle was lower in ACLR limbs compared with the contralateral (MD, 4.88°; 95% CI, 3.0°-6.7°; P < .001) and control (MD, 6.01°; 95% CI, 2.0°-10.0°; P < .002) limbs. A lower quadriceps force compared with the contralateral (MD, 4.14 BW; 95% CI, 3.4-4.9 BW; P < .001) and control (MD, 2.83 BW; 95% CI, 1.4-4.3 BW; P < .001) limbs was also found. CONCLUSION: Lower PFJ contact forces and a combination of quadriceps force deficits and smaller knee flexion angle were found in the ACLR compared with the contralateral and control limbs even after clearance to RTS. CLINICAL RELEVANCE: Despite rehabilitation and subsequent clearance to RTS, differences in PFJ contact forces are present after ACLR. Current rehabilitation and RTS battery may not be effective and sensitive enough to identify and address these differences.

Understanding Fear after an Anterior Cruciate Ligament Injury: A Qualitative Thematic Analysis Using the Common-Sense Model.

Fear is a significant factor affecting successful return to sport following an anterior cruciate ligament (ACL) injury. However, there is a lack of understanding of the emotional drivers of fear and how fear beliefs are formed. This study qualitatively explored the contextual and emotional underpinnings of fear and how these beliefs were formed, with reference to the Common-Sense Model of Self-Regulation. Face-to-face online interviews were conducted with ACL-injured participants (n = 18, 72% female) with a mean age of 28 years (range 18-50 years). Participants were either 1 year post ACL reconstruction surgery (n = 16) or at least 1 year post injury without surgery (n = 2) and scored above average on a modified Tampa Scale of Kinesiophobia. Four participants were playing state-level sport or higher. Five themes emerged describing factors contributing to fear: 'External messages', 'Difficulty of the ACL rehabilitation journey', 'Threat to identity and independence', 'Socioeconomic factors', and 'Ongoing psychological barriers'. A sixth theme, 'Positive coping strategies', provided insight into influences that could reduce fear and resolve negative behaviors. This study identified a broad range of contextual biopsychosocial factors which contribute to fear, supporting the notion that ACL injuries should not be treated through a purely physical lens. Furthermore, aligning the themes to the common-sense model provided a conceptual framework conveying the inter-related, emergent nature of the identified themes. The framework provides clinicians with a means to understanding fear after an ACL injury. This could guide assessment and patient education.

Aspetar clinical practice guideline on rehabilitation after anterior cruciate ligament reconstruction.

This guideline was developed to inform clinical practice on rehabilitation after anterior cruciate ligament reconstruction (ACLR) and was performed in accordance with the Appraisal of Guidelines for REsearch & Evaluation II (AGREE II) instrument and used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. A Guideline Development Group systematically searched and reviewed evidence using randomised clinical trials and systematic reviews to evaluate the effectiveness of rehabilitation interventions and guide clinicians and patients on the content of the optimal rehabilitation protocol after ACLR.The guideline targets patients during rehabilitation after ACLR and investigates the effectiveness of the available interventions to the physiotherapist, alone or in combination (eg, exercise, modalities, objective progression criteria). Exercise interventions should be considered the mainstay of ACLR rehabilitation. However, there is little evidence on the dose-response relationship between volume and/or intensity of exercise and outcomes. Physical therapy modalities can be helpful as an adjunct in the early phase of rehabilitation when pain, swelling and limitations in range of motion are present. Adding modalities in the early phase may allow earlier pain-free commencement of exercise rehabilitation. Return to running and return to training/activity are key milestones for rehabilitation after ACLR. However, there is no evidence on which progression or discharge criteria should be used.While there is a very low level of certainty for most components of rehabilitation, most of the recommendations provided in this guideline were agreed to by expert clinicians. This guideline also highlights several new elements of ACLR management not reported previously.

The dose-response of pain throughout a Nordic hamstring exercise intervention.

The Nordic hamstring exercise (NHE) reduces hamstring injury incidence. Compliance to large exercise volumes of the NHE is poor, with exercise related soreness often seen as a contributing factor. We investigated the dose-response of NHE exposure with delayed onset muscle soreness (DOMS) and non-DOMS pain. Forty males were randomized to a 6-week intervention of four different NHE dosages: Group 1: very low volume; Group 2: low volume; Group 3: initial high to low volume; Group 4: low to high volume. Group 4 experienced more DOMS (p < 0.05) and non-DOMS pain (p = 0.030) than other groups. High volumes of NHE increase DOMS and non-DOMS pain while lower volume protocols have lesser DOMS and non-DOMS pain responses.

An Investigation of the Nature of Fear within ACL-Injured Subjects When Exposed to Provocative Videos: A Concurrent Qualitative and Quantitative Study.

Fear is a factor contributing to poor return to sport after an anterior cruciate (ACL) injury, however the identification and assessment of fear is challenging. To improve understanding of fear, this study qualitatively and quantitatively assessed responses to videos depicting threat to knee stability in people who had experienced an ACL injury. ACL-injured participants who had above average fear on the Tampa Scale of Kinesiophobia and were at least 1-year post-injury/surgery were eligible. Participants were shown four videos depicting sequentially increasing threat to their knee stability (running, cut-and-pivot, feigned knee injury during cut-and-pivot, series of traumatic knee injuries). Qualitative interviews explored participants feeling related to viewing the videos. Participants quantitatively self-rated fear and distress in response to each video. Seventeen participants were included in this study (71% female, with an average time since last ACL injury of 5 ½ years). Five themes were identified: (1) Evoked physiological responses, (2) Deeper contextualisation of the meaning of an ACL injury influencing bodily confidence, (3) Recall of psychological difficulties, (4) Negative implications of a re-injury, and (5) Change to athletic identity. Quantitatively, direct proportionality was noticed between threat level and reported fear and distress. Specifically, participants reported increasing levels of fear and distress as the videos progressed in threat level, with the largest increase seen between a cut-and-pivot movement to a feigned injury during a cut and pivot. The results support the notion that in addition to being a physical injury, an ACL injury has more complex neurophysiological, psychological, and social characteristics which should be considered in management. Using video exposure in the clinic may assist identification of underlying psychological barriers to recovery following an ACL injury, facilitating person-centred care.

High-speed running during match-play before and after return from hamstring injury in professional footballers.

Hamstring injuries constitute the single largest cause of lost playing time in professional football. While restoring high-speed running ability is paramount for rehabilitation from these injuries, little evidence exists regarding the extent of return to sport running performance after hamstring injury in football. We examined medical and match performance data available from a sample of 38 professional soccer players competing in the Qatar Stars League (N = 1426 observations) to describe high-speed running performance during match-play prior and subsequent to a hamstring strain injury. Multivariable-adjusted random-effects generalized additive models estimated post- versus pre-hamstring injury differences in maximal speed (km/h), high-speed running (>20 km/h), and sprinting (>25 km/h) distance. Mean effects and uncertainty (95% confidence interval, CI) were interpreted against the estimated random match-to-match variability in maximal sprinting speed, high-speed running distance, and sprinting running distance of ±1.67 km/h (95% CI, 1.62-1.72 km/h), ±102 m (95% CI, 99-105 m), and ±60 m (95% CI, 58-61 m), respectively. The estimated post- versus pre-hamstring injury mean differences in maximal sprinting speed, high-speed running distance, and sprinting running distance primary outcomes were -0.25 km/h (95% CI, -0.38 to -0.12 km/h), -43 m (95% CI, -56 to -30 m), and -22 m (95% CI, -29 to -16 m). Players returning to football match-play after hamstring strain injury experienced reductions in high-speed match physical performance that were well within normal match-to-match variation in performance.

Association Between Injury Mechanisms and Magnetic Resonance Imaging Findings in Rectus Femoris Injuries in 105 Professional Football Players.

OBJECTIVE: To describe the injury mechanism and its association with magnetic resonance imaging (MRI) injury findings in acute rectus femoris injuries. DESIGN: Combined retrospective and prospective descriptive injury study. Retrospective cohort from January 2010 to October 2013 and prospective cohort from October 2013 to January 2019. SETTING: Specialized sports medicine hospital. PARTICIPANTS: Male professional football players older than 18 years playing in a national football league, referred for injury assessment within 7 days after an acute rectus femoris injury, with a positive finding on MRI. INDEPENDENT VARIABLES: Rectus femoris muscle injury MRI findings in relation to injury mechanism in male football players. MAIN OUTCOME MEASURES: Rectus femoris injury mechanism (kicking, sprinting, and others), MRI injury location, and grade. RESULTS: There were 105 injuries in total, with 60 (57.1%) and 45 (42.8%) injuries from the retrospective and prospective cohorts, respectively. Kicking was the injury mechanism in 57 (54.3%) of all acute rectus femoris injuries, sprinting represented 32 (30.4%), and 16 (15.2%) were classified as others. There were 20 (19.05%) free tendon, 67 (63.8%) myotendinous junction and/or intramuscular tendon, and 18 (17.1%) peripheral myofascial located injuries. All free tendon injuries were related to kicking and graded as a complete tear of at least one of the tendons in 15/20 (75.0%) cases. CONCLUSIONS: Kicking seems to be an important mechanism related to complete ruptures and injuries occurring at the proximal free tendon. Sprinting was the other most common mechanism but was never associated with injury to the proximal free tendon.

Symmetry in Triple Hop Distance Hides Asymmetries in Knee Function After ACL Reconstruction in Athletes at Return to Sports.

BACKGROUND: After anterior cruciate ligament reconstruction (ACLR), a battery of strength and hop tests is frequently used to determine the readiness of an athlete to successfully return to sports. However, the anterior cruciate ligament reinjury rate remains alarmingly high. PURPOSE: To evaluate the lower limb function of athletes after ACLR at the time when they had been cleared to return to sports (RTS). We aimed to evaluate if passing discharge criteria ensures restoration of normal lower limb biomechanics in terms of kinematics, kinetics, work, and percentage work contribution during a triple hop for distance. STUDY DESIGN: Controlled laboratory study. METHODS: Integrated 3-dimensional motion analysis was performed in 24 male athletes after ACLR when cleared to RTS and 23 healthy male controls during the triple-hop test. The criteria for RTS were (1) clearance by the surgeon and the physical therapist, (2) completion of a sports-specific on-field rehabilitation program, and (3) limb symmetry index >90% after quadriceps strength and hop battery tests. Lower limb and trunk kinematics, as well as knee joint moments and work, were calculated. Between-limb differences (within athletes after ACLR) and between-group differences (between ACLR and control groups) were evaluated using mixed linear models. RESULTS: Although achieving 97% limb symmetry in distance hopped and displaying almost 80% symmetry for knee work absorption in the second rebound and third landing, the ACLR cohorts demonstrated only 51% and 66% limb symmetry for knee work generation in the first and second rebound phases, respectively. During both work generation phases of the triple hop, the relative contribution of the involved knee was significantly smaller, with a prominent compensation from the hip joint (P < .001, for all phases) as compared with the uninvolved limb and the controls. In addition, patients deployed a whole body compensatory strategy to account for the between-limb differences in knee function, mainly at the hip, pelvis, and trunk. CONCLUSION: Symmetry in the triple hop for distance masked important deficits in the knee joint work. These differences were more prominent during work generation (concentric-propulsive) than work absorption (eccentric-landing). CLINICAL RELEVANCE: Symmetry in hop distance during the triple hop test masked significant asymmetries in knee function after ACLR and might not be the appropriate outcome to use as a discharge criterion. Differences between limbs in athletes after ACLR were more prominent during the power generation than the absorption phase.

Physiotherapy Rehabilitation in Subjects Diagnosed with Subacromial Impingement Syndrome Does Not Normalize Periscapular and Rotator Cuff Muscle Onset Time of Activation.

Clinicians suggest that rehabilitation of Subacromial Impingement Syndrome (SIS) should target improving movement patterns to ensure better clinical outcomes. Understanding changes in onset time of activation patterns and associated changes in clinical outcomes could improve our understanding of rehabilitation strategies. In this prospective longitudinal study, we examined neuromuscular firing patterns and clinical features before and after a standardized physiotherapy program in subjects diagnosed with SIS. Electromyography (EMG) recordings of eleven shoulder muscles were taken at the initial and discharge consultation in 34 male volunteers diagnosed with SIS. EMG recording was performed during flexion, scaption, and abduction at slow, medium, and fast speeds with a loaded (3 kg) and unloaded arm, as well as rotational motion, rotational strength, pain, and shoulder function. Completion of standardized shoulder physiotherapy program for SIS resulted in improvements in clinical outcomes. Resulted showed inconsistent differences of onset time of activation mainly in some of the periscapular muscles for all movements. No differences were seen on the EMG recordings for rotator cuff muscles. Differences in range of motion, strength and function were shown. Despite some changes in onset time of activation, this study was not able to demonstrate consistent changes of onset time of activation of the periscapular and rotator cuff muscles.

The dominant leg is more likely to get injured in soccer players: systematic review and meta-analysis.

In soccer (football), dominant limb kicking produces higher ball velocity and is used with greater frequency than the non-dominant limb. It is unclear whether limb dominance has an effect on injury incidence. The purpose of this systematic review with meta-analysis is to examine the relationship between limb dominance and soccer injuries. Studies were identified from four online databases according to PRISMA guidelines to identify studies of soccer players that reported lower extremity injuries by limb dominance. Relevant studies were assessed for inclusion and retained. Data from retained studies underwent meta-analyses to determine relative risk of dominant versus non-dominant limb injuries using random-effects models. Seventy-four studies were included, with 36 of them eligible for meta-analysis. For prospective lower extremity injury studies, soccer players demonstrated a 1.6 times greater risk of injury to the dominant limb (95% CI [1.3-1.8]). Grouped by injury location, hamstring (RR 1.3 [95% CI 1.1-1.4]) and hip/groin (RR 1.9 [95% CI 1.3-2.7]) injuries were more likely to occur to the dominant limb. Greater risk of injury was present in the dominant limb across playing levels (amateurs RR 2.6 [95% CI 2.1-3.2]; youths RR 1.5 [95% CI 1.26-1.67]; professionals RR 1.3 [95% CI 1.14-1.46]). Both males (RR 1.5 [95% CI 1.33-1.68)] and females (RR 1.5 [95% CI 1.14-1.89]) were more likely to sustain injuries to the dominant limb. Future studies investigating soccer injury should adjust for this confounding factor by using consistent methods for assigning limb dominance and tracking use of the dominant versus non-dominant limb.

Current perspectives and clinical practice of physiotherapists on assessment, rehabilitation, and return to sport criteria after anterior cruciate ligament injury and reconstruction. An online survey of 538 physiotherapists.

OBJECTIVES: To evaluate the perspectives and clinical practice of physiotherapists regarding rehabilitation after anterior cruciate ligament reconstruction (ACLR). DESIGN: Online survey. SETTING: Survey platform. PARTICIPANTS: Greek physiotherapists. OUTCOME MEASURES: The survey consisted of 7 sections: participant demographics, importance of ACLR rehabilitation, clinical measurements, practice, criteria to progress rehabilitation, return to running and return to sport. RESULTS: Significant variability in measures and criteria used for clinical decision-making were found including: limb symmetry in strength and function, knee range of motion and effusion, progression, and return to sport criteria. The majority of the practitioners (28.3%) extrapolate knee strength from hop capacity. Return to running ranged from 3 to 5 months post-operatively reflecting that this was tied to physical capacities, not time from surgery. 70.0% of the Greek physiotherapists would allow return to sport ≤9 months after ACLR. Agreement was found in using: physical measures, function, and dynamic stability in ACLR rehabilitation, but the mode and interpretation varied substantially. Less than 29.0% of the physiotherapists reported using patient-reported outcome measures in their decision-making. CONCLUSION: Current ACLR rehabilitation practices in Greece are largely not aligned with the contemporary scientific evidence and guidelines.

Lower medial hamstring activity after ACL reconstruction during running: a cross-sectional study.

OBJECTIVE: Anterior cruciate ligament reconstruction (ACLR) predisposes footballers for subsequent ACL and hamstring (HS) injury. This case series examines HS muscle activation patterns during the running in ACLR patients (bone-patellar tendon-bone (BTB) and (HS) graft) after completion of functional criteria allowing return to training. METHODS: Electromyography (EMG) recorded from medial and lateral HS bilaterally during treadmill running (12, 14 and 16 km/hour) from 21 male ACLR patients on average 7 months from surgery (5-9) that underwent (HS) (n=12) or BTB reconstruction (n=9) were compared with 19 healthy runners. Main outcome measures: EMG signal was normalised to peak during the running. Pairwise comparisons were made for each muscle group examining stance and swing activation for mean and peak EMG for each patient group and leg. RESULTS: Significantly lower relative peak activation in stance (not swing) phase for medial HS was seen for all conditions with effect sizes ranging from -0.63 (controls, BTB non-injured leg) to -1.09 (HS injured). For lateral HS only BTB injured were significantly lower in stance phase (-1.05). CONCLUSION: ACLR patients show neuromuscular alterations during different phases of running. The finding of reduced medial HS activity in stance phase might have implications for knee instability and HS muscle injury on resumption of sport.

Effect of speed and gradient on plantar force when running on an AlterG® treadmill.

BACKGROUND: Anti-gravity treadmills are used to decrease musculoskeletal loading during treadmill running often in return to play rehabilitation programs. The effect different gradients (uphill/downhill running) have on kinetics and spatiotemporal parameters when using an AlterG® treadmill is unclear with previous research focused on level running only. METHODS: Ten well-trained healthy male running athletes ran on the AlterG® treadmill at varying combinations of bodyweight support (60, 80, and 100% BW), speed (12 km/hr., 15 km/hr., 18 km/hr., 21 km/hr., and 24 km/hr), and gradients (- 15% decline, - 10, - 5, 0, + 5, + 10 + 15% incline), representing a total of 78 conditions performed in random order. Maximum plantar force and contact time were recorded using a wireless in-shoe force sensor insole system. RESULTS: Regression analysis showed a linear relationship for maximum plantar force with bodyweight support and running speeds for level running (p < 0.0001, adj. R2 = 0.604). The linear relationship, however, does not hold for negative gradients at speeds 12 & 15 km/h, with a relative 'dip' in maximum plantar force across all assisted bodyweight settings. CONCLUSIONS: Maximum plantar force peaks are larger with faster running and smaller with more AlterG® assisted bodyweight support (athlete unweighing). Gradient made little difference except for a downhill grade of - 5% decreasing force peaks as compared to level or uphill running.

Participant characteristics are poorly reported in exercise trials in tendinopathy: A systematic review.

OBJECTIVE: To evaluate the reporting of eligibility criteria and baseline participant characteristics in randomised controlled trials investigating the effects of exercise interventions in tendinopathy. METHODS: Randomised controlled trials investigating the effects of exercise therapy compared to a non-exercising intervention in upper and lower limb tendinopathy were included. Data extraction was categorised into the following domains: participant demographics, tendinopathy descriptors, general health, participant recruitment and eligibility criteria. RESULTS: The review included the following tendinopathies: Achilles (n = 9), gluteal (n = 2), lateral elbow tendinopathy (n = 15), patellar (n = 3) plantar (n = 3), and rotator cuff (n = 13). Age, sex, duration of symptoms and symptom severity were commonly reported across the review, while prior history of tendinopathy was poorly reported (6/45). Variables such as physical activity level (17/45), sleep (0/45), psychological factors (2/45), medication at baseline (8/45), co morbid health complaints (10/45) and sociodemographic factors (11/45) were poorly reported across the included studies. Substantial variation existed between studies in the specific eligibility criteria used. CONCLUSION: The findings of this systematic review demonstrate that participant characteristics are poorly reported in exercise trials in tendinopathy. To improve effectiveness of exercise interventions in tendinopathy, improved reporting of participant characteristics may allow better comparisons and targeted interventions for specific subgroups.

Notions of "optimal" posture are loaded with meaning. Perceptions of sitting posture among asymptomatic members of the community.

BACKGROUND: Notions of "optimal" posture are widespread in modern society and strongly interconnected with preconceived beliefs. OBJECTIVES: To quantitatively evaluate spinal posture among members of the community during habitual sitting, and when asked to assume an "optimal" posture. DESIGN: Observational study. METHODS: Marker-based kinematic analyses of the head, spine, and pelvis were conducted on 100 individuals. Habitual sitting posture and self-perceived "optimal" posture, and whether participants believed that their habitual sitting reflected an "optimal" posture, were evaluated. The Wilcoxon signed-rank test assessed angular differences between the two postures adopted. Exploratory post-hoc analyses were conducted by using the Mann-Whitney U test to assess differences between genders. RESULTS: None of the participants stated that their habitual sitting was "optimal". Statistically significant differences were observed in most of the measured angles (p < 0.001) between habitual and self-perceived "optimal" posture. In habitual sitting posture, a significant interaction with gender was found only in the thoracolumbar (p < 0.05) and pelvic (p < 0.001) angles, with small effect sizes. In self-perceived "optimal" posture females were more extended in the head, upper thoracic, lower thoracic, lumbar and pelvic (p < 0.01) regions, than the males. CONCLUSIONS: A group of young, asymptomatic participants, consistently changed their habitual sitting posture to a more upright posture when asked to assume an "optimal" sitting posture, although the amount of change observed varied between spinal regions. These findings also highlight gender differences in not just habitual sitting posture, but also the degree to which habitual sitting posture is modified when trying to assume an "optimal" sitting posture.

Match High-Speed Running Distances Are Often Suppressed After Return From Hamstring Strain Injury in Professional Footballers.

BACKGROUND: High-speed running is commonly implicated in the genesis of hamstring injury. The success of hamstring injury management is typically quantified by the duration of time loss or reinjury rate. These metrics do not consider any loss in performance after returning to play from hamstring injury. It is not known to what extent high-speed running is altered on return to play after such injury. HYPOTHESIS: Match high-speed running distance will change after returning from hamstring injury. STUDY DESIGN: Non-randomized cohort. LEVEL OF EVIDENCE: Level 3. METHODS: Match high-speed running distance in highest level professional football (soccer, Rugby League, Rugby Union, and Australian Rules) were examined for a minimum of 5 games prior and subsequent to hamstring strain injury for individual differences using a linear regression models approach. A total of 22 injuries in 15 players were available for analysis. RESULTS: Preinjury cumulative high-speed running distances were strongly correlated for each individual (r2 = 0.92-1.0; P < 0.0001). Pre- and postinjury high-speed running data were available for a median of 15 matches (range, 6-15). Variance from the preinjury high-speed running distance was significantly less (P = 0.0005) than the post injury values suggesting a suppression of high-speed running distance after returning from injury. On return to play, 7 of the 15 players showed a sustained absolute reduction in preinjury high-speed running distance, 7 showed no change, and 1 player (only) showed an increase. Analysis of subsequent (second and third injury) return to play showed no differences to return from the index injury. CONCLUSION: Return to play was not associated with return to high-speed running performance for nearly half of the players examined, although the same number showed no difference. Persisting deficits in match high-speed running may exist for many players after hamstring strain injury. CLINICAL RELEVANCE: Returning to play does not mean returning to (high-speed running) performance for nearly half of the high-level professional football players examined in this study. This suggests that successful return to play metrics should be expanded from simple time taken and recurrence to include performance.

Progression of Strength, Flexibility, and Palpation Pain During Rehabilitation of Athletes With Acute Adductor Injuries: A Prospective Cohort Study.

OBJECTIVE: To investigate the relationship between repeated clinical measures and the progression of rehabilitation of male athletes with acute adductor injuries. DESIGN: Prospective observational cohort study. METHODS: Male athletes with acute adductor injuries received a standardized criteria-based rehabilitation program with 4 repeated clinical measures during rehabilitation: the extent of palpation pain (length and width in centimeters), the bent-knee fall-out test (BKFO; in centimeters), hip abduction range of motion (in degrees), and eccentric hip adduction strength (in Newton meters per kilogram). We analyzed the association between each clinical measure and the percent progression of rehabilitation until return to sport (RTS), divided into 2 RTS milestones: (1) clinically pain free, and (2) completion of controlled sports training. RESULTS: The analyses included 61 male athletes for RTS milestone 1 and 50 athletes for RTS milestone 2, and 381 to 675 tests were performed for each clinical measure. The median time to RTS milestones 1 and 2 was 15 days (interquartile range, 12-29 days) and 24 days (interquartile range, 16-34 days), respectively. Each repeated clinical measure individually explained 13% to 36% of the variance in rehabilitation progression to the RTS milestones. The extent of palpation pain explained the highest variance of the progression of rehabilitation (R2 = 0.26-0.27 for length and R2 = 0.36 for width, P<.001). Eccentric adduction strength (R2 = 0.19-0.27, P<.001) improved throughout rehabilitation, whereas the flexibility tests (BKFO, R2 = 0.13-0.15; P<.001 and hip abduction range of motion, R2 = 0.19-0.21; P<.001) returned to normal values early in rehabilitation. CONCLUSION: Repeated measures of adductor strength, flexibility, and palpation pain provided only a rough impression of rehabilitation progress following acute adductor injuries in male athletes. These clinical measures cannot define a precise recovery point during rehabilitation. J Orthop Sports Phys Ther 2021;51(3):126-134. Epub 28 Oct 2020. doi:10.2519/jospt.2021.9951.