Isometric exercise and pain in patellar tendinopathy: A randomized crossover trial

Is It Time to Step outside the Laboratory? The Feasibility of Field-Based Examination of Exercise-Induced Hypoalgesia in Elite Badminton Athletes with and without Knee Pain

Aim

To investigate the feasibility of testing exercise-induced hypoalgesia (EIH) in a field setting. The effect of knee pain on EIH was also explored.

Design

Within-group pre-post design.

Materials and Methods

Fourteen athletes (8 male, 6 female) competing at an international level in badminton were tested on the sideline during an in-season training session. Participants completed questionnaires and a single leg decline squat to evaluate the presence of knee pain. A blinded examiner measured PPT over the quadriceps muscle before and after two conditions (3-minute quiet rest and 3-minute isometric wall squat).

Results

The exercise protocol was completed by 13 (93%) participants. Mean (SD) exertion was 8.4 (1.7), and mean thigh pain was 7.9 (2.0) at 3 minutes. Very high reliability was observed for PPT collected before and after rest (ICC 0.94, 95% CI 0.85, 0.98). PPT significantly increased by 22.4% (95% CI 15.1, 29.7) after wall squat but not after rest. Relative increases in PPT were similar in participants with and without knee pain on single leg decline squat (22.2% versus 22.6%, 7 participants each).

Conclusion

Simple, field-based tests of endogenous analgesia are feasible and could provide new opportunities to evaluate an athlete's risk of persistent pain.

Determination of differences in ultrasound parameters for patellar tendons in males with unilateral patellar tendinopathy-An ancillary analysis of data from two randomized controlled trials

PURPOSE

To investigate power Doppler (PD) activity and tendon structure (between the injured and contralateral limb) in patients with unilateral patellar tendinopathy (PT) using ultrasonography (US). Secondly, the aim was to determine the intra-rater reliability of the PD activity and tendon structure.

METHODS

This study analyzed US baseline data from 57 male participants with symptomatic unilateral PT who had been enrolled in one of two randomized clinical trials. Data were analyzed to examine if systematic differences existed between injured and contralateral limbs using Fiji ImageJ.

RESULTS

The PD activity of the symptomatic tendon was larger 25.6 (Q1 = 14.9; Q3 = 41.6) mm2 than the asymptomatic 0 (Q1 = 0.0; Q3 = 0.0) mm2 (p < 0.001). There was a significantly greater tendon thickness at the proximal (2.5 mm 95% CI [2.0; 3.0]), mid (0.8 mm 95% CI [0.5; 1.1]), and distal (0.2 mm 95% CI [0.1; 0.4]) part of the tendon for the symptomatic compared to the asymptomatic tendon. Intra-rater reliability for PD activity and tendon structure ranged from moderate-to-excellent (0.74; 0.99).

CONCLUSION

These results provide mean estimates for tendon thickness of symptomatic and asymptomatic tendons, that can be used for clinicians to reliably estimate pathological tendon thickness.

The Impact of Different Ischemic Preconditioning Pressures on Pain Sensitivity and Resistance Exercise Performance

ABSTRACT

Kataoka, R, Song, JS, Yamada, Y, Hammert, WB, Seffrin, A, Spitz, RW, Wong, V, Kang, A, and Loenneke, JP. The impact of different ischemic preconditioning pressures on pain sensitivity and resistance exercise performance. J Strength Cond Res 38(5): 864-872, 2024-To determine (a) the impact of ischemic preconditioning pressures (applied as a % of arterial occlusion pressure [AOP]) on pressure pain threshold (PPT) and resistance exercise performance and (b) whether changes in performance could be explained by changes in PPT. Subjects ( n = 39) completed 4 protocols in a randomized order: (a) ischemic preconditioning (IPC) at 110% AOP (IPC 110%), (b) IPC at 150% AOP (IPC 150%), (c) IPC at 10% AOP (Sham), and (d) time-matched control (CON). Each protocol included 4 cycles of 5 minutes of occlusion followed by 5 minutes of reperfusion. Pressure pain threshold was taken before and after. Discomfort ratings were given at the end of each cycle. Every visit finished with 2 sets of 75-second maximal isokinetic unilateral elbow flexion or extension. Overall, IPC 110% and IPC 150% resulted in similar increases in PPT relative to CON [110%: difference of 0.36 (0.18, 0.54) kg·m -2 ; 150%: difference of 0.377 (0.15, 0.59) kg·m -2 ] and Sham. Both resulted in greater discomfort than Sham and CON, with IPC 150% inducing greater discomfort than IPC 110% (BF 10 : 14.74). There were no differences between the conditions for total work (BF 10 : 0.23), peak torque (BF 10 : 0.035), or average power (BF 10 : 0.159). We did not find evidence that PPT mediated performance. We did not detect changes in performance with 2 different relative pressures greater than AOP. Our mean applied pressures were lower than those used previously. There might be a minimal level of pressure (e.g., >150% of AOP) that is required to induce ergogenic effects of ischemic preconditioning.

Maximal Lower Limb Strength in Patellar Tendinopathy: A Systematic Review With Meta-Analysis

OBJECTIVE

To investigate whether lower limb strength is reduced in people with patellar tendinopathy (PT) compared with asymptomatic control individuals or the asymptomatic contralateral limb.

DATA SOURCES

MEDLINE, PubMed, Scopus, and Web of Science.

STUDY SELECTION

To be included in the systematic review and meta-analysis, studies were required to be peer reviewed, published in the English language, and case control investigations; include participants with a clinical diagnosis of PT and an asymptomatic control or contralateral limb group; and include an objective measure of lower limb maximal strength.

DATA EXTRACTION

We extracted descriptive statistics for maximal strength for the symptomatic and asymptomatic limbs of individuals with PT and the limb(s) of the asymptomatic control group, inferential statistics for between-groups differences, participant characteristics, and details of the strength-testing protocol. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool for analytical cross-sectional studies.

DATA SYNTHESIS

Of the 23 included studies, 21 reported knee strength, 3 reported hip strength, and 1 reported ankle strength. Random-effects models (Hedges g) were used to calculate the pooled effect sizes (ESs) of muscle strength according to the direction of joint movement and type of contraction. The pooled ESs (95% CI) for maximal voluntary isometric contraction knee-extension strength, concentric knee-extension strength, and concentric knee-flexion strength were 0.54 (0.27, 0.80), 0.78 (0.30, 1.33), and 0.41 (0.04, 0.78), respectively, with all favoring greater strength in the asymptomatic control group. Researchers of 2 studies described maximal eccentric knee-extensor strength with no differences between the PT and asymptomatic control groups. In 3 studies, researchers measured maximal hip strength (abduction, extension, and external rotation), and all within-study ESs favored greater strength in the asymptomatic control group.

CONCLUSIONS

Isometric and concentric knee-extensor strength are reduced in people with PT compared with asymptomatic control individuals. In contrast, evidence for reduced eccentric knee-extension strength in people with PT compared with asymptomatic control individuals is limited and inconsistent. Although evidence is emerging that both knee-flexion and hip strength may be reduced in people with PT, more examination is needed to confirm this observation.

Patellar tendinopathy: an overview of prevalence, risk factors, screening, diagnosis, treatment and prevention

Patellar tendinopathy (PT), or jumper's knee, is an overuse injury that occurs in professional, as well as recreational, athletes. This condition is a noncontact injury, typically characterized by gradually increasing pain in the patellar tendon. It is prevalent in participants of several sports, but it occurs mostly in jumping sports. The diagnosis of PT is primarily clinical; however, imaging techniques can be useful as well. Risk factors differ between sexes, playing conditions, the kind of sport, playing level and personal characteristics. Screening is an essential tool to assess PT. This condition affects athletic performance and often persists for years. The use of preventative methods is imperative because of the persistence of this condition, especially in elite athletes who sometimes end their career after long and failed treatments. There are a wide variety of treatment and rehabilitation options available, the majority of which are non-operative, such as eccentric exercises, cryotherapy, platelet-rich plasma (PRP) injections, and anti-inflammatory strategies. If conservative treatment fails, surgery is the next most preferable step. Even though there are many surgical treatment methods, there is no clear evidence on what is the most effective approach to address PT. Taking this into consideration, as well as the extent of this clinical entity, novel therapeutic techniques, as well as screening and prevention methods, are expected to emerge in the near future.

Do adolescents with Osgood-Schlatter display nociplastic pain manifestations compared to controls: A cross-sectional study

OBJECTIVES

Osgood-Schlatter disease is an overuse musculoskeletal pain condition. The pain mechanism is considered nociceptive, but no studies have investigated nociplastic manifestations. This study investigated pain sensitivity and inhibition evaluated through exercise-induced hypoalgesia in adolescents with and without Osgood-Schlatter.

DESIGN

Cross-sectional study.

METHODS

Adolescents underwent a baseline assessment comprising clinical history, demographics, sports participation, and pain severity rated (0-10) during a 45-second anterior knee pain provocation test, consisting of an isometric single leg squat. Pressure pain thresholds were assessed bilaterally at the quadriceps, tibialis anterior muscle, and the patella tendon before and after a three-minute wall squat.

RESULTS

Forty-nine adolescents (27 Osgood-Schlatter, 22 controls) were included. There were no differences in the exercise-induced hypoalgesia effect between Osgood-Schlatter and controls. Overall, an exercise-induced hypoalgesia effect was detected at the tendon only in both groups with a 48 kPa (95 % confidence interval 14 to 82) increase in pressure pain thresholds from before to after exercise. Controls had higher pressure pain thresholds at the patellar tendon (mean difference 184 kPa 95 % confidence interval 55 to 313), tibialis anterior (mean difference 139 kPa 95 % confidence interval 24 to 254), and rectus femoris (mean difference 149 kPa 95 % confidence interval 33 to 265). Higher anterior knee pain provocation severity was associated with lower exercise-induced hypoalgesia at the tendon (Pearson correlation = 0.48; p = 0.011) in participants with Osgood-Schlatter.

CONCLUSIONS

Adolescents with Osgood-Schlatter display increased pain sensitivity locally, proximally, and distally but similar endogenous pain modulation compared to healthy controls. Greater Osgood-Schlatter severity appears to be associated with less efficient pain inhibition during the exercise-induced hypoalgesia paradigm.

Hip flexion angle affects longitudinal muscle activity of the rectus femoris in leg extension exercise

PURPOSE

We investigated the effect of the hip flexion angle (HFA) on the longitudinal muscle activity of the rectus femoris (RF) during leg extension exercise (LEE).

METHODS

We conducted an acute study in a specific population. Nine male bodybuilders performed isotonic LEE using a leg extension machine at three different HFAs: 0°, 40°, and 80°. Participants extended their knees from 90° to 0° at each HFA setting for four sets of ten repetitions at 70% of the one-repetition maximum. The transverse relaxation time (T2) of the RF was measured before and after LEE using magnetic resonance imaging. We analyzed the rate of change in the T2 value in the proximal, middle, and distal regions of the RF. The subjective sensation of muscle contraction of the quadriceps was measured using a numerical rating scale (NRS) and compared with the T2 value which was the objective index.

RESULTS

At 80°, the T2 value in the middle RF was lower than that in the distal RF (p < 0.05). The T2 values at 0° and 40° HFA were higher than those at 80° HFA in the proximal (p < 0.05, p < 0.01) and middle RF (p < 0.01, p < 0.01). The NRS scores were inconsistent with the objective index.

CONCLUSION

These results suggest that the 40° HFA is practical for region-specific strengthening of the proximal RF, and subjective sensation alone as an indication of training may not activate the proximal RF. We conclude that activation of each longitudinal section of the RF is possible depending on the hip joint angle.

Effects of active scapular correction on cervical range of motion, pain, and pressure pain threshold in patients with chronic neck pain and depressed scapula: a randomized controlled trial

BACKGROUND

Correction of scapular alignment is advocated as a component for alleviating symptoms for patients with neck pain.

OBJECTIVE

The study aimed to examine the effect of active scapular correction on cervical range of motion (ROM), pain, and pressure pain threshold (PPT) in patients with chronic neck pain with depressed scapula.

METHODS

A randomized control trial research design was conducted. Twenty-eight participants with chronic neck pain and depressed scapula were randomly assigned to either the intervention (n = 14) or control (n = 14) group. Active cervical rotation ROM, pain at maximum cervical rotation, and PPT over the upper trapezius muscle region were measured at baseline and post active scapular correction.

RESULTS

The participants in the intervention group showed significantly greater active cervical rotation ROM and less pain at maximum cervical rotation than the control group, both on the ipsilateral (p < 0.01) and contralateral (p < 0.05) sides of the depressed scapula. No significant difference in PPT between the groups was demonstrated (p = 0.194).

CONCLUSION

Active scapular correction intervention resulted in an immediate increase in active cervical rotation ROM and a decrease in neck pain at maximum cervical rotation.

Effect of Increased Pressure Pain Threshold on Resistance Exercise Performance With Blood Flow Restriction

ABSTRACT

Kataoka, R, Song, JS, Bell, ZW, Wong, V, Spitz, RW, Yamada, Y, and Loenneke, JP. Effect of increased pressure pain threshold on resistance exercise performance with blood flow restriction. J Strength Cond Res XX(X): 000-000, 2022-This study aimed to examine whether increasing pressure pain threshold (PPT) through isometric handgrip exercise (HG) affects the number of repetitions completed and discomfort with knee extension exercise (KE) with blood flow restriction (BFR), and examine whether performing additional exercise leads to a further increase in PPT. Forty-one participants completed 2 trials: rest followed by low-load KE with BFR at 80% of resting arterial occlusion pressure (Rest + KE BFR) and low-intensity (30% of maximal strength) HG exercise followed by KE with BFR (HG + KE BFR). Pressure pain threshold was measured before and after exercise at the forearm and tibialis anterior. Results are presented as median difference (95% credible interval). Pressure pain threshold increased at the forearm (Bayes factor [BF10]: 5.2 × 107) and tibialis anterior (BF10: 1.5 × 106) after HG exercise. However, this did not lead to greater repetitions being completed with BFR exercise (0.2 [-0.1, 0.6] repetitions, BF10: 0.07). Pressure pain threshold after BFR exercise was not augmented over that observed with HG exercise (0.02 [-0.15, 0.2] kg·cm-2, BF10: 0.175) at the forearm. More data are needed in the lower body to determine which model best fits the data (BF10: 0.84). Discomfort with BFR exercise was not different between conditions (1.0 [-2.3, 4.4] arbitrary units, BF10: 0.10). The pain-reducing effect of prior exercise did not change the repetitions completed with BFR exercise, suggesting that the change in PPT may not have been great enough to alter performance. Performing additional exercise did not elicit further increases in PPT nor was perceived discomfort to BFR exercise altered by changes in PPT.

Surgical Management of Patellar Tendinopathy Results in Improved Outcomes and High Rates of Return to Sport: A Systematic Review

Although the majority of patients with patellar tendinopathy (PT) can be treated nonoperatively, operative management may be indicated for recalcitrant cases. While several surgical techniques have been described, there is limited understanding of postoperative outcomes and expectations regarding return to activity and sport. The purpose of this study was to characterize the clinical outcomes associated with the surgical management of PT with an emphasis on return to sport (RTS) rates. We hypothesized that surgical management would lead to clinically important improvements in patient-reported outcomes (PROs) with high rates of RTS and RTS at the same level. A comprehensive search of the PubMed, Medline, and Embase databases was performed in December 2020. Level of evidence studies I through IV, investigating results of surgical management for PT (PRO, functional outcomes, pain, and/or RTS), were included. The search was performed in accordance with the Preferred Reported Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Forty clinical studies reporting on surgery for PT satisfied inclusion criteria, with 1,238 total knees undergoing surgery for PT. A comparison of pre- and postoperative Victorian Institute of Sport Assessment, patellar tendon (VISA-P) scores (mean difference: 41.89, p < 0.00001), Lysholm scores (mean difference: 41.52, p < 0.00001), and visual analogue scale (VAS) pain scores (mean difference: 5, p < 0.00001) demonstrated clinically and statistically significant improvements after surgery. The overall RTS rate following operative management was 89.8% (95% confidence interval [CI]: 86.4-92.8, I ² = 56.5%) with 76.1% (95% CI: 69.7.5-81.9, I ² = 76.4%) of athletes returning to the same level of activity. Surgery for PT provides meaningful improvement in patient reported outcomes and pain while allowing athletes to RTS at high rates with levels of participation similar to that of preinjury. Comparative studies of open and/or arthroscopic surgery are still limited but current evidence suggests better rates of RTS for arthroscopic surgery compared with open surgery. This is a systematic review of level-I to -IV studies.

Assessment of the reporting quality of resistance training interventions in randomised controlled trials for lower limb tendinopathy: A systematic review

OBJECTIVES

1. To describe what exercises and intervention variables are used in resistance training interventions in randomised controlled trials for lower limb tendinopathy 2. To assess completeness of reporting as assessed by the Consensus on Exercise Reporting Template (CERT) and the Toigo and Boutellier framework. 3. To assess the implementation of scientific resistance training principles. 4. To assess therapeutic quality of exercise interventions with the i-CONTENT tool.

DATA SOURCES

We searched MEDLINE, CINAHL, AMED, EMBase, SPORTDiscus, and the Cochrane library databases.

REVIEW METHODS

Systematic review of randomised controlled trials that reported using resistance exercises for lower limb tendinopathies.

RESULTS

We included 109 RCTs. Eccentric heel drops were the most common exercise (43 studies), followed by isotonic heel raises (21), and single leg eccentric decline squats (18). Reporting of exercise descriptor items from the Toigo and Boutellier framework ranged from 0-13, with an average score of 9/13, and only 7 studies achieved a full 13/13. Reporting of items from the CERT ranged from 0-18, with an average score of 14/19. No study achieved a full 19/19, however 5 achieved 18/19. Scoring for resistance training principles ranged from 1-10, with only 11 studies achieving 10/10. Reporting across studies for the i-CONTENT tool ranged from 2-7, with an average score of 5 across included studies. A total of 19 studies achieved a full 7/7 score. Less than 50% of studies achieved an overall low risk of bias, highlighting the methodological concerns throughout studies.

CONCLUSION

The reporting of exercise descriptors and intervention content was generally high across RCTs for lower limb tendinopathy, with most allowing exercise replication. However, reporting for some tendinopathies and content items such as adherence was poor, limiting optimal translation to clinical practice.

Resistance Training Interventions for Lower Limb Tendinopathies: A Scoping Review of Resistance Training Reporting Content, Quality, and Scientific Implementation

The objectives of this scoping review were as follows: (1) to describe what exercises and intervention variables are used in resistance training interventions for lower limb tendinopathy,  (2) to assess the completeness of reporting as assessed by the Consensus on Exercise Reporting Template (CERT) and the Toigo and Boutellier framework, and (3) to assess the implementation of scientific resistance training principles. We searched MEDLINE, CINAHL, AMED, Embase, SPORTDiscus, and Cochrane Library databases. Randomized controlled trials, cohort studies, case series, case reports, and observational studies that reported using resistance exercises for lower limb tendinopathies were considered for inclusion, with 194 studies meeting the inclusion criteria. Completeness of the reporting of exercise descriptors and programme variables was assessed by the CERT and the Toigo and Boutellier framework. Reporting of exercise descriptor items from the Toigo and Boutellier framework ranged from 0 to 13, with an average score of 9/13, with only 9 studies achieving a full 13/13. Reporting of items from the CERT ranged from 0 to 18, with an average score of 13/19. No study achieved a full 19/19; however, 8 achieved 18/19. Scoring for resistance training principles ranged from 1 to 10, with only 14 studies achieving 10/10. Eccentric heel-drops were the most common exercise (75 studies), followed by isotonic heel raises (38), and single-leg eccentric decline squats (27). The reporting of exercise descriptors and intervention content was high across studies, with most allowing exercise replication, particularly for Achilles and patellar tendinopathy. However, reporting for some tendinopathies and content items such as adherence was poor, limiting optimal translation to clinical practice.

Effects of β-Hydroxy β-Methylbutyric Supplementation in Combination with Conservative Non-Invasive Treatments in Athletes with Patellar Tendinopathy: A Pilot Study

The aim of the present study was to analyze the effect of conservative non-invasive treatments based on eccentric training, stretching and extracorporeal shock wave therapy (ESWT) supplemented with β-Hydroxy β-methylbutyric (HMB) or placebo (PLAC) on body composition, pain and muscular function (jump ability, muscular power and muscular strength) in athletes with patellar tendinopathy (PT). In a double-blind randomized trial, 8 athletes (4 males and 4 females) performed a physical rehabilitation for 4 weeks. They were randomly divided into two experimental groups (two males and two females in each one) that ingested HMB (HMBG) or PLAC (PLACG). In pre- and post-intervention were assessed body composition, pain, countermovement jump (CMJ), back-squat (BS) for analyzing peak power (W) (PPPP), load (kg) associated to PPPP (PPKG) and mean velocity (m/s) (PPMV) in addition to a 5-RM leg extension tests. An interaction intervention·supplementation (p = 0.049; Ƞ2p = 0.774) was observed in the height reached in the CMJ as an intervention effect in PPPP detected for the HMBG (p = 0.049). In addition, an enhancement in PPKG (p = 0.028; Ƞ2p = 0.842) was detected in the intervention, but not in PPMV, as an increase in the intervention in the 5-RM test (p = 0.001; Ƞ2p = 0.981) was observed. No changes were noted on body composition or pain (p > 0.05). The combination of eccentric training with stretching and ESWT increased concentric muscular power and strength after 4 weeks without changes in body lean mass or pain. In addition, HMB supplementation could enhance the power muscular performance in athletes with PT, optimizing the intervention adaptions.

Management of Patellar Tendinopathy Through Monitoring, Load Control, and Therapeutic Exercise: A Systematic Review

CONTEXT

Patellar tendinopathy presents with persistent tendon pain located in the lower pole of the patella and loss of function related to mechanical load. Although its pathogenesis is not completely clear, conservative treatment including exercise is the main intervention of patellar tendinopathy treatment.

OBJECTIVE

To describe the efficacy of patellar tendinopathy management through therapeutic exercise, and control and monitoring of loads.

EVIDENCE ACQUISITION

MEDLINE, WoS, Cochrane Plus, PEDro, and the gray literature were searched from inception to July 2021. Based on the PICO strategy, the inclusion criteria were clinical trials published in English or Spanish; outcomes of function, pain, and strength; patients with patellar tendinopathy with no age or gender limitations; using an active intervention; and at least a methodological quality equal to or greater than 3 points on the Jadad scale. All data were analyzed by 2 independent reviewers (P.N.-M. and D.H.-G.). Studies were qualitatively synthesized using a descriptive synthesis. The methodological quality and risk of bias assessment were performed with the PEDro and Jadad scale, respectively.

EVIDENCE SYNTHESIS

A total of 136 articles were identified, of which 12 met the eligibility criteria. All of them were regarded as presenting a moderate risk of bias and their methodological quality was considered acceptable to good. Recovering patellar tendinopathy with therapeutic exercise seems to significantly improve function, pain, and strength after intervention and even lasted over time.

CONCLUSION

A treatment based on load monitoring and physical exercise has proven to be effective in rehabilitating patellar tendinopathy, with positive results in the short and medium term.

Management of patellar tendinopathy: a systematic review and network meta-analysis of randomised studies

Objectives

We performed a systematic review and network meta-analysis (NMA) of randomised controlled trials (RCTs) to provide insights into the effectiveness of available treatment modalities in patellar tendinopathy(PT).

Methods

Several databases were searched in May 2021 for RCTs assessing the effectiveness of any intervention compared with any other intervention, placebo or no treatment for pain and/or function in PT. The risk of bias and strength of evidence were assessed with the Cochrane Collaboration and GRADE (Grading of Recommendations, Assessment, Development and Evaluations)/GRADE-NMA tools.

Results

A total of 37 RCTs were eligible that assessed 33 different interventions and their combinations, most represented by single studies. Based on pairwise meta-analyses of two RCTs, extracorporeal shockwave therapy (ESWT) does not appear to be superior to sham ESWT (eccentric exercise in both groups) for short-term pain (mean differences (MD) +0.1, 95% CI (−0.8 to 1), p=0.84) or function (MD −1.8, 95% CI (–8 to 4.4), p=0.57). Based on a pairwise meta-analysis of three RCTs, isometric exercise appears as effective as isotonic exercise for immediate postintervention pain relief (MD −1.03, 95% CI (−2.6 to 0.5), p=0.19). Our NMA showed that topical glyceryl trinitrate (GTN) and hyaluronic acid injection, both combined with eccentric exercise and moderate, slow resistance exercise had the highest probability of being the most effective interventions (low/very low strength of evidence).

Conclusions

Promising interventions with inadequate evidence, such as topical GTN, hyaluronic acid injections and isometric and slow resistance exercise, should be further investigated through high-quality RCTs. Meanwhile, eccentric loading with or without adjuncts should remain the first-line treatment for all individuals with patellar tendinopathy.

The Unknown Prevalence of Postrandomization Bias in 15 Physical Therapy Journals: A Methods Review

OBJECTIVES

To determine the prevalence of prospective clinical trial registration and postrandomization bias in published musculoskeletal physical therapy randomized clinical trials (RCTs).

DESIGN

A methods review.

LITERATURE SEARCH

Articles indexed in MEDLINE and published between January 2016 and July 2020 were included.

STUDY SELECTION CRITERIA

Two independent blinded reviewers identified the RCTs using Covidence. We included RCTs related to musculoskeletal interventions that were published in International Society of Physiotherapy Journal Editors member journals.

DATA SYNTHESIS

Data were extracted independently for the variables of interest from the identified RCTs by 2 blinded reviewers. The data were presented descriptively or in frequency tables.

RESULTS

One hundred thirty-eight RCTs were identified. One third of RCTs were consistent with their prospectively registered intent (49/138); consistency with prospectively registered intent could not be determined for two thirds (89/138) of the RCTs. Four RCTs (8%)reported inconsistent results with the primary aims and 7 (14%) with the outcomes from the prospective clinical trial registry, despite high methodological quality (Physiotherapy Evidence Database [PEDro] scale score). Differences between prospectively registered and non-prospectively registered RCTs for PEDro scale scores had a medium effect size (r = 0.30). Two of 15 journals followed their clinical trial registration policy 100% of the time; in 1 journal, the published RCTs were consistent with the clinical trial registration.

CONCLUSION

Postrandomization bias in musculoskeletal physical therapy RCTs could not be ruled out, due to the lack of prospective clinical trial registration and detailed data analysis plans. J Orthop Sports Phys Ther 2021;51(11):542-550. Epub 21 Sep 2021. doi:10.2519/jospt.2021.10491.

Effect of a common exercise programme with an individualised progression criterion based on the measurement of neuromuscular capacity versus current best practice for lower limb tendinopathies (MaLaGa trial): a protocol for a randomised clinical trial

INTRODUCTION

High-load resistance training has shown positive effects in pain and function in lower limb tendinopathies. However, some authors suggest that current exercise programmes produce an increase in tolerance to load and exercise in general but without fixing some existing issues in tendinopathy. This may indicate the need to include training aspects not currently taken into account in the current programmes. The main objective of this study will be to compare the effect of a common exercise protocol for the three predominant lower limb tendinopathies (Achilles, patellar and gluteal), based on an individualised control of the dose and training of specific aspects of the neuromuscular system versus the current best practice for each location.

METHODS AND ANALYSIS

This study will be conducted among people with mid-portion Achilles, patellar or gluteal tendinopathy. The participants allocated to the experimental group will perform a 14-week innovative common therapeutic exercise programme. Participants allocated to the control group will carry out a 14-week exercise programme based on the best current practice for each of the studied locations. The Victorian Institute of Sports Assessment questionnaire will be considered the primary outcome. Pain, central sensitisation, fear avoidance behaviour, quality of life, treatment satisfaction, lower-limb strength and function, and high-density electromyography profile will be evaluated as secondary outcomes. Outcomes will be assessed at baseline, 7 weeks, after the intervention (week 14), 26 weeks and 52 weeks.

ETHICS AND DISSEMINATION

The study has been approved by the Portal de Ética de la Investigación Biomédica de Andalucía Ethics Committee (1221-N-19). All participants will be informed about the purpose and content of the study and written informed consent will be completed. The results of this study will be published in a peer-reviewed journal and will be disseminated electronically and in print.

TRIAL REGISTRATION NUMBER

NCT03853122; Pre-results.

Should Exercises be Painful or not? Effects on Clinical and Experimental Pain in Individuals with Shoulder Pain

Exercise can reduce pain, however the effect of painful versus non-painful exercises is uncertain. The primary aim of this randomized crossover study was to compare the effect of painful versus nonpainful isometric shoulder exercises on pain intensity after exercise in individuals with rotator cuff-related shoulder pain. Secondary exploratory aims were to describe the effects on pressure pain thresholds (PPTs), conditioned pain modulation (CPM) and muscle strength. On separate days, 35 individuals performed painful isometric shoulder exercises (external rotation; 20% above pain threshold), nonpainful isometric shoulder exercises (external rotation; 20% below pain threshold), and a rest condition, in randomised order. Shoulder pain intensity, PPTs, CPM, and external rotation strength were assessed before, immediately after and 45 minutes after conditions. No significant differences were observed between painful and nonpainful exercises. Visual analogue scale scores increased immediately after both painful and non-painful exercises compared with rest (P = .047, partial ƞ² = .07), but were similar to preexercise levels after 45 minutes. No changes in PPTs, CPM, or muscle strength after exercises compared with rest were observed. Painful and non-painful isometric exercises caused a moderate but short-lasting increase in shoulder pain in individuals with RCRSP. Isometric exercises had no effect on pain sensitivity and shoulder muscle strength or CPM. Perspective: This study evaluated for the first time in individuals with rotator cuff-related shoulder pain the effects of painful versus non-painful isometric exercises on different pain-related outcome measures. Both painful and non-painful isometric exercises caused a moderate but relatively short-lasting increase in shoulder pain in individuals with rotator cuff-related shoulder pain. Trial registration number: (ClinicalTrials.gov) NCT03675399.

The Benefits of Strength Training on Musculoskeletal System Health: Practical Applications for Interdisciplinary Care

Global health organizations have provided recommendations regarding exercise for the general population. Strength training has been included in several position statements due to its multi-systemic benefits. In this narrative review, we examine the available literature, first explaining how specific mechanical loading is converted into positive cellular responses. Secondly, benefits related to specific musculoskeletal tissues are discussed, with practical applications and training programmes clearly outlined for both common musculoskeletal disorders and primary prevention strategies.

Clinical Outcomes, Structure, and Function Improve With Both Heavy and Moderate Loads in the Treatment of Patellar Tendinopathy: A Randomized Clinical Trial

BACKGROUND

Loading interventions have become a predominant treatment strategy for tendinopathy, and positive clinical outcomes and tendon tissue responses may depend on the exercise dose and load magnitude.

PURPOSE/HYPOTHESIS

The purpose was to investigate if the load magnitude influenced the effect of a 12-week loading intervention for patellar tendinopathy in the short term (12 weeks) and long term (52 weeks). We hypothesized that a greater load magnitude of 90% of 1 repetition maximum (RM) would yield a more positive clinical outcome, tendon structure, and tendon function compared with a lower load magnitude of 55% of 1 RM when the total exercise volume was kept equal in both groups.

STUDY DESIGN

Randomized clinical trial; Level of evidence, 1.

METHODS

A total of 44 adult participants with chronic patellar tendinopathy were included and randomized to undergo moderate slow resistance (MSR group; 55% of 1 RM) or heavy slow resistance (HSR group; 90% of 1 RM). Function and symptoms (Victorian Institute of Sport Assessment-Patella questionnaire [VISA-P]), tendon pain during activity (numeric rating scale [NRS]), and ultrasound findings (tendon vascularization and swelling) were assessed before the intervention, at 6 and 12 weeks during the intervention, and at 52 weeks from baseline. Tendon function (functional tests) and tendon structure (ultrasound and magnetic resonance imaging) were investigated before and after the intervention period.

RESULTS

The HSR and MSR interventions both yielded significant clinical improvements in the VISA-P score (mean ± SEM) (HSR: 0 weeks, 58.8 ± 4.3; 12 weeks, 70.5 ± 4.4; 52 weeks, 79.7 ± 4.6) (MSR: 0 weeks, 59.9 ± 2.5; 12 weeks, 72.5 ± 2.9; 52 weeks, 82.6 ± 2.5), NRS score for running, NRS score for squats, NRS score for preferred sport, single-leg decline squat, and patient satisfaction after 12 weeks, and these were maintained after 52 weeks. HSR loading was not superior to MSR loading for any of the measured clinical outcomes. Similarly, there were no differences in functional (strength and jumping ability) or structural (tendon thickness, power Doppler area, and cross-sectional area) improvements between the groups undergoing HSR and MSR loading.

CONCLUSION

There was no superior effect of exercising with a high load magnitude (HSR) compared with a moderate load magnitude (MSR) for the clinical outcome, tendon structure, or tendon function in the treatment of patellar tendinopathy in the short term. Both HSR and MSR showed equally good, continued improvements in outcomes in the long term but did not reach normal values for healthy tendons.

REGISTRATION

NCT03096067 (ClinicalTrials.gov identifier).

Does isometric exercise result in exercise induced hypoalgesia in people with local musculoskeletal pain? A systematic review

OBJECTIVE

The aim of this review was to investigate if exercise induced hypoalgesia (EIH) occurs following isometric muscle contraction in people with local musculoskeletal symptoms.

DESIGN

Systematic review.

DATA SOURCES

MEDLINE, EMBASE, CINAHL & SportDiscus electronic databases were searched (inception to April 2020).

ELIGIBILITY CRITERIA

Two authors independently evaluated eligibility. Randomised controlled and crossover (repeated measures) trials that measured the effects of isometric exercise in participants with localised musculoskeletal pain during, and up to 2 hours after isometric exercise were included. Other inclusion criteria included comparison to another intervention, or comparison to healthy controls. Primary outcomes were experimentally induced pain thresholds and secondary outcomes included measures of pain sensitivity from clinical testing.

RESULTS

13 studies with data from 346 participants were included for narrative synthesis. EIH was reported in some upper and lower limb studies but there were no consistent data to show isometric exercises were superior to comparison interventions.

CONCLUSION

There was no consistent evidence for EIH following isometric exercise in people with musculoskeletal pain. These findings are different to those reported in asymptomatic populations (where EIH is consistently demonstrated) as well as conditions associated with widespread symptoms such as fibromyalgia (where isometric exercise may induce hyperalgesia). Although well tolerated when prescribed, isometric exercise did not induce EIH consistently for people seeking care for local musculoskeletal symptoms. The variance in the dose, location of contraction and intensity of protocols included in this review may explain the inconsistent findings. Further work is required to better understand endogenous analgesia in musculoskeletal pain conditions.

Effects of Physical Training on Physical and Psychological Parameters in Individuals with Patella Tendon Myopathy: A Systematic Review and Meta-Analysis

The effectiveness of physical training on physical and psychological parameters in individuals with patella tendinopathy has not been investigated in a systematic review and meta-analysis. The aim of the present study was to determine the effects of physical exercise interventions for measures of physical and psychological performance in subjects with patella tendinopathy. A computerised systematic literature search was conducted in the electronic databases PubMed, Medline, and Web of Science from January 1960 to July 2020. Initially, 506 articles were identified for review of which eleven articles met the inclusion criteria. Our results revealed a small effect (weighted mean standardized mean difference (SMD) = 0.12; nine studies) of physical training on the psychological measure Victorian Institute of Sport Assessment–Patellar tendon scale and a medium effect (weighted mean SMD = 0.61; five studies) on the psychological measure visual analogue scale—both in favour of the intervention group. In contrast, a small effect (weighted mean SMD = −0.05; two studies) in favour of the control group was detected for the physical measure muscle power. Compared to the control condition, physical training seems to be an effective means to improve psychological but not physical parameters in individuals with patella tendinopathy; although conclusions on the latter could have been biased by the small amount of eligible studies (n = 2). In addition, the predetermined cut-off value of ≥6 for the Physiotherapy Evidence Database scale score (i.e., assessment of methodological quality) was only achieved by six out of eleven studies. Thus, further research of high methodological quality is needed to verify whether there is or is not an effect of physical training on physical parameters in persons with patella tendinopathy.

Randomised, cross-over trial on the effect of isotonic and isometric exercise on pain and strength in proximal hamstring tendinopathy: trial protocol

Background

Proximal hamstring tendinopathy (PHT) is a condition that occurs at all ages and levels of sporting participation. Presenting as localised lower buttock pain with tasks such as squatting and sitting, it can cause disability with sport, work and other activities of daily living. Recent research has investigated the effect of isometric exercise on pain and strength with a range of tendinopathies but there are no published studies on PHT. This protocol paper details a study investigating the effectiveness of isometric compared with isotonic exercise on pain and strength in people with PHT.

Methods/Design

The study is a prospective, cross-over randomised controlled trial (RCT). Twenty participants with PHT, recruited from the local community and sporting clubs will be recruited for the study. Participants will receive one session of isotonic hamstring strength exercises and one session of isometric hamstring exercise, with random allocation to the order of intervention.

Primary outcomes will be hamstring strength measured with a dynamometer and pain with a functional task, assessed immediately following and 45 min after intervention. A secondary outcome will be pain with sitting assessed 24 hours after intervention.

The effect of isotonic versus isometric exercise on hamstring pain and strength will be determined using a repeated measures linear mixed model. Further analyses will determine the proportion of patients with clinically important pain and strength improvements, using relative risks, χ² testing and number needed to treat.

Discussion

This RCT protocol will investigate the effect of isometric compared with isotonic exercise for PHT.

Tendinopathy

Tendinopathy describes a complex multifaceted pathology of the tendon, characterized by pain, decline in function and reduced exercise tolerance. The most common overuse tendinopathies involve the rotator cuff tendon, medial and lateral elbow epicondyles, patellar tendon, gluteal tendons and the Achilles tendon. The prominent histological and molecular features of tendinopathy include disorganization of collagen fibres, an increase in the microvasculature and sensory nerve innervation, dysregulated extracellular matrix homeostasis, increased immune cells and inflammatory mediators, and enhanced cellular apoptosis. Although diagnosis is mostly achieved based on clinical symptoms, in some cases, additional pain-provoking tests and imaging might be necessary. Management consists of different exercise and loading programmes, therapeutic modalities and surgical interventions; however, their effectiveness remains ambiguous. Future research should focus on elucidating the key functional pathways implicated in clinical disease and on improved rehabilitation protocols.

Stretching and relaxing the plantar fascia may change plantar fascia thickness but not pressure pain thresholds: a cross-sectional study of patients with plantar fasciopathy

Background

Despite the established relevance of ultrasonography and assessment of pressure pain thresholds in patients with plantar fasciopathy, patient and probe positioning has been mostly ignored and are not necessarily reported in research. The primary aim of this study was to compare plantar fascia thickness in stretched and relaxed positions in patients with plantar fasciopathy. The secondary aim was to compare plantar heel pressure pain thresholds in these positions.

Methods

In this cross-sectional study, we measured the plantar fascia thickness with ultrasonography, and localised pressure pain thresholds using pressure algometry of 20 patients with plantar fasciopathy. These were assessed bilaterally, with the plantar fascia in both a stretched and relaxed position. In the stretched position, toes were maximally dorsiflexed, while in the relaxed position participants’ feet were hanging freely over the end of the table.

Results

The plantar fascia of the most symptomatic foot was significantly thicker when stretched compared with the relaxed position (sagittal: mean difference 0.2 mm, 95%CI: 0.1–0.4, P = 0.013; frontal: mean difference − 0.27, 95%CI: − 0.49 to − 0.06, P = 0.014). The plantar fascia was significantly thinner in the frontal plane compared with the sagittal plane in both positions (stretched: mean difference − 0.2 mm, 95%CI: − 0.42 to − 0.03, P = 0.025; relaxed: mean difference − 0.3 mm, 95%CI:-0.49 to − 0.08, P = 0.008). There was no difference between pressure pain thresholds in stretched or relaxed positions in either foot (P > 0.4).

Conclusions

The plantar fascia was significantly thicker in a stretched compared with a relaxed position and in the sagittal compared with the frontal plane, but differences were smaller than the standard deviation. Pressure pain thresholds were not different between the positions. These results highlight the importance of how ultrasonography is performed and reported in research to allow for replication.

Trial registration

The study was pre-registered September 25th, 2017 on ClinicalTrials.gov (NCT03291665).

Effectiveness of progressive tendon-loading exercise therapy in patients with patellar tendinopathy: a randomised clinical trial

OBJECTIVE

To compare the effectiveness of progressive tendon-loading exercises (PTLE) with eccentric exercise therapy (EET) in patients with patellar tendinopathy (PT).

METHODS

In a stratified, investigator-blinded, block-randomised trial, 76 patients with clinically diagnosed and ultrasound-confirmed PT were randomly assigned in a 1:1 ratio to receive either PTLE or EET. The primary end point was clinical outcome after 24 weeks following an intention-to-treat analysis, as assessed with the validated Victorian Institute of Sports Assessment for patellar tendons (VISA-P) questionnaire measuring pain, function and ability to play sports. Secondary outcomes included the return to sports rate, subjective patient satisfaction and exercise adherence.

RESULTS

Patients were randomised between January 2017 and July 2019. The intention-to-treat population (mean age, 24 years, SD 4); 58 (76%) male) consisted of patients with mostly chronic PT (median symptom duration 2 years). Most patients (82%) underwent prior treatment for PT but failed to recover fully. 38 patients were randomised to the PTLE group and 38 patients to the EET group. The improvement in VISA-P score was significantly better for PTLE than for EET after 24 weeks (28 vs 18 points, adjusted mean between-group difference, 9 (95% CI 1 to 16); p=0.023). There was a trend towards a higher return to sports rate in the PTLE group (43% vs 27%, p=0.13). No significant between-group difference was found for subjective patient satisfaction (81% vs 83%, p=0.54) and exercise adherence between the PTLE group and EET group after 24 weeks (40% vs 49%, p=0.33).

CONCLUSIONS

In patients with PT, PTLE resulted in a significantly better clinical outcome after 24 weeks than EET. PTLE are superior to EET and are therefore recommended as initial conservative treatment for PT.

"Does isometric exercise improve leg stiffness and hop pain in subjects with Achilles tendinopathy? A feasibility study"

BACKGROUND

In Achilles tendinopathy (AT) the ability to store and recycle elastic energy during ground contact phase is often altered. A measure of this function is represented by leg stiffness (LS). Immediate responses in LS following therapeutic intervention have not been examined.

OBJECTIVE

The aim of this paper was to examine the feasibility of the protocol in participants with AT.

DESIGN

Single cohort feasibility study.

PARTICIPANTS

Adults with persistent AT pain, symptoms on palpation and less than 80 points on the Visa-A questionnaire.

INTERVENTION

heavy isometric exercise sequence in plantarflexion.

OUTCOME MEASURES

Feasibility was assessed by evaluating: the willingness of participants to enroll into the study, the number of eligible participants, the recruitment rate, adherence to the intervention, the drop-out rate, the tolerability of the protocol. LS, reactive strength index, pain and rate of perceived effort were secondary outcomes.

RESULTS

22 AT were eligible for data collection and 19 entered the statistical analysis. The intervention was well tolerated, no withdrawals. Pain scores were low during both the intervention and the assessment. Immediate improvements in LS and pain were recorded.

CONCLUSIONS

The isometric exercise protocol was feasible. Future research should investigate its effectiveness.

Exercise-induced hypoalgesia after acute and regular exercise: experimental and clinical manifestations and possible mechanisms in individuals with and without pain

This review describes methodology used in the assessment of the manifestations of exercise-induced hypoalgesia in humans and previous findings in individuals with and without pain. Possible mechanisms and future directions are discussed.

Exercise and physical activity is recommended treatment for a wide range of chronic pain conditions. In addition to several well-documented effects on physical and mental health, 8 to 12 weeks of exercise therapy can induce clinically relevant reductions in pain. However, exercise can also induce hypoalgesia after as little as 1 session, which is commonly referred to as exercise-induced hypoalgesia (EIH). In this review, we give a brief introduction to the methodology used in the assessment of EIH in humans followed by an overview of the findings from previous experimental studies investigating the pain response after acute and regular exercise in pain-free individuals and in individuals with different chronic pain conditions. Finally, we discuss potential mechanisms underlying the change in pain after exercise in pain-free individuals and in individuals with different chronic pain conditions, and how this may have implications for clinical exercise prescription as well as for future studies on EIH.

Landing biomechanics are not immediately altered by a single-dose patellar tendon isometric exercise protocol in male athletes with patellar tendinopathy: A single-blinded randomized cross-over trial

OBJECTIVES

To a) determine the acute effects of a single-dose patellar tendon isometric exercise protocol on involved limb landing biomechanics in individuals with patellar tendinopathy and asymptomatic patellar tendon pathology, and b) determine if individuals with patellar tendinopathy demonstrated changes in pain following a single-dose patellar tendon isometric exercise protocol.

DESIGN

Single-blinded randomized cross-over trial.

SETTING

Laboratory; PARTICIPANTS: 28 young male athletes with symptomatic (n = 13, age: 19.62 ± 1.61) and asymptomatic (n = 15, age: 21.13 ± 1.88) patellar tendinopathy.

MAIN OUTCOME MEASURES

Participants completed a single-dose patellar tendon isometric exercise protocol and a sham-TENS protocol, randomized and separated by 7-10 days. Pain-levels during a single-limb decline squat (SLDS) and three-dimensional biomechanics were collected during a double-limb jump-landing task before and after each intervention protocol. A mixed-model repeated measures ANOVA was conducted to compare change scores for all dependent variables.

RESULTS

There were no group × intervention interactions for change in pain (F_{(1, 26)} = 0.555, p = 0.463). There was one significant group × intervention interaction for vertical ground reaction force (VGRF) (F_{(1, 26)} = 5.33, p = 0.029). However, post-hoc testing with Bonferroni correction demonstrated no statistical significance for group (SYM: t = -1.679, p = 0.119; ASYM: t = -1.7, p = 0.107) or intervention condition (isometric: t = -2.58, p = 0.016; sham-TENS: 0.72, p = 0.460). There were no further significant group × intervention interactions (p > 0.05).

CONCLUSIONS

A single-dose patellar tendon isometric exercise protocol did not have acute effects on landing biomechanics or pain levels in male athletes with patellar tendinopathy or asymptomatic patellar tendon pathology.

Effectiveness of isometric exercise in the management of tendinopathy: a systematic review and meta-analysis of randomised trials

Objective

To systematically review and critically appraise the literature on the effectiveness of isometric exercise in comparison with other treatment strategies or no treatment in tendinopathy.

Design

A systematic review and meta-analysis of randomised controlled trials.

Data sources

Electronic searches of Medline, Cumulative Index to Nursing and Allied Health Literature, EMBASE and Cochrane were undertaken from inception to May 2020.

Methods

Overall quality of each study was determined based on a combined assessment of internal validity, external validity and precision. For each outcome measure, level of evidence was rated based on the system by van Tulder et al.

Results

Ten studies were identified and included in the review, including participants with patellar (n=4), rotator cuff (n=2), lateral elbow (n=2), Achilles (n=1) and gluteal (n=1) tendinopathies. Three were of good and seven were of poor overall quality. Based on limited evidence (level 3), isometric exercise was not superior to isotonic exercise for chronic tendinopathy either immediately following treatment or in the short term (≤12 weeks) for any of the investigated outcome measures. Additionally, for acute rotator cuff tendinopathy, isometric exercise appears to be no more effective than ice therapy in the short term (limited evidence; level 3).

Summary

Isometric exercise does not appear to be superior to isotonic exercise in the management of chronic tendinopathy. The response to isometric exercise is variable both within and across tendinopathy populations. Isometric exercise can be used as part of a progressive loading programme as it may be beneficial for selected individuals.

PROSPERO registration number

CRD42019147179.

To Compare the Effect of Eccentric Exercises and Isometric Exercises for Achilles Tendinitis in Skaters

Background

Achilles tendinitis is one of the commonest injuries that happen to skaters. Roller skates traditionally have four wheels onto axles, one under the ball of the foot and one under the heel. Skaters have to maintain a closed kinematics chain which involves continuous trunk and hip flexion along with knee flexion and ankle dorsiflexion. It creates angular tension and strain in the muscles and tendons which can lead to different types of musculotendinous injuries. As not many studies has not been done on the prospect in India this study was done with a objective to compare the effect eccentric exercise and isometric exercise on Achilles tendinitis for skaters.

Methods

A Quasi-experimental study with 40 subjects of the age group between 15 and 25 was administered the VISA-A Questionnaire and VAS as outcome measures. A sample size of 40 was separated into two groups of 20 participants each into Group A (eccentric) and Group B (isometric). Pre-test and post-test were done using the VISA-A questionnaire and VAS Scale in the Study period- 4 weeks.

Results

There was a significant difference during the comparison between pre-test and post-test values (p < 0.005) of isometric exercise and eccentric exercise by VISA-A questionnaire and VAS scale but there was insignificance during the comparison of post-test values (p > 0.005) of the same.

Conclusion

The study concludes that there is a significant improvement in Achilles tendinitis when assessed with VISA-A questionnaire and VAS Scale for both the exercise; that is, eccentric and isometric, individually but it isn’t statistically significant enough to choose one method of intervention over the other.