Application of eccentric exercise on an Australian Rules football player with recurrent hamstring injuries

Ultrasound-Guided Percutaneous Needle Electrolysis and Rehab and Reconditioning Program for Rectus Femoris Muscle Injuries: A Cohort Study with Professional Soccer Players and a 20-Week Follow-Up

Rectus femoris muscle strains are one of the most common injuries occurring in sports such as soccer. The purpose of this study was to describe the safety and feasibility of a combination of percutaneous needle electrolysis (PNE) and a specific rehab and reconditioning program (RRP) following an injury to the rectus femoris in professional soccer players. Thirteen professional soccer players received PNE treatment 48 h after a grade II rectus femoris muscle injury, followed by a the RRP 24 h later. Assessment of recovery from injury was done by registering the days taken to return to train (RTT), return to play (RTP), and structural and functional progress of the injured muscle was registered through ultrasound imaging and match-GPS parameters. Also, adverse events and reinjuries were recorded in the follow up period of twenty weeks. The RTT registered was 15.62 ± 1.80 days and RTP was 20.15 ± 2.79 days. After fourteen days, the ultrasound image showed optimal repair. Match-GPS parameters were similar before and after injury. There were no relapses nor were any serious adverse effects reported during the 20-week follow-up after the RTP. A combination of PNE and a specific RRP facilitated a faster RTP in previously injured professional soccer players enabling them to sustain performance and avoid reinjuries.

Modulation of physiological cross-sectional area and fascicle length of vastus lateralis muscle in response to eccentric exercise

In the current study, we investigated the effect of lengthening velocity during eccentric exercise on the modulation of the physiological cross-sectional area (PCSA) and fascicle length of the vastus lateralis (VL) muscle. We hypothesized a greater increase in muscle PCSA after training with lower lengthening velocities and a greater increase in fascicle length after higher lengthening velocities. Forty-seven young men were randomly assigned to either a control (n = 14) or an intervention group (n = 33). The participants of the intervention group were randomly allocated to one of four isokinetic eccentric training protocols of the knee extensors, with four different knee angular velocities (45°/s, 120°/s, 210°/s and 300°/s), yet similar range of motion (25-100° knee joint angle), load magnitude (100% of isometric maximum) and load volume (i.e. similar time under tension for one training set). Before and after an 11-week training period with 3 times per week exercise, muscle volume, pennation angle, fascicle length and PCSA of the VL muscle were measured using magnetic resonance imaging and ultrasonography. After the training, the VL muscle volume and fascicle length increased similarly and approximately 5% in all investigated protocols. The PCSA and pennation angles of the VL did not change after any exercise protocol, indicating negligible radial muscle adaptation after the training. The reason for the found hypertrophy of VL muscle after eccentric training in a wide range of lengthening velocities was mainly a longitudinal muscle growth. Further, the longitudinal muscle growth was independent of the lengthening velocity.

Does a bounding exercise program prevent hamstring injuries in adult male soccer players? - A cluster-RCT

Background

Although the Nordic Hamstring Exercise (NHE) prevents hamstring injury in soccer players effectively, the annual incidence of these injuries still increases. This may be because of poor long‐term compliance with the program. Furthermore, the timing and amplitude of gluteal and core muscle activation seem to play an important role in hamstring injury prevention, the NHE program was not designed to improve activation of these muscles. Therefore, we propose plyometric training as an alternative to reduce hamstring injuries in soccer players.

Purpose

To determine the preventive effect of the Bounding Exercise Program (BEP) on hamstring injury incidence and severity in adult male amateur soccer players.

Study design

A cluster‐Randomized Controlled Trial.

Methods

Thirty‐two soccer teams competing in the first‐class amateur league were cluster‐randomized into the intervention or control group. Both groups were instructed to perform their regular training program, and the intervention group additionally performed BEP. Information about player characteristics was gathered at baseline and exposure, hamstring injuries and BEP compliance were weekly registered during one season (2016‐2017).

Results

The data of 400 players were analyzed. In total, 57 players sustained 65 hamstring injuries. The injury incidence was 1.12/1000 hours in the intervention group and 1.39/1000 hours in the control group. There were no statistically significant differences in hamstring injury incidence (OR = 0.89, 95% CI 0.46‐1.75) or severity between the groups (P > 0.48).

Conclusion

In this large cluster‐randomized controlled trial, no evidence was found for plyometric training in its current form to reduce hamstring injuries in amateur soccer players.

Kinematic and electromyographic analysis of the Askling L-Protocol for hamstring training

Hamstring injuries are common in field sport athletes. Eccentric strength training of the hamstring muscles is an integral component of rehabilitation programs. The Askling L-Protocol comprises three exercises [extender; diver; glider] that load the hamstrings during eccentric activity. When compared to a conventional exercise-based rehabilitation program, the Askling L-Protocol has been shown to reduce the time to return to sport following hamstring injury and prevalence of injury recurrence. Nevertheless, the mechanisms behind its efficacy have yet to be studied. In this work, we conducted a kinematic and electromyographic analysis of the exercises of the Askling L-Protocol. Eleven healthy individuals performed each of the exercises while electromyographic data from four muscles (including two hamstring muscles) were recorded. Hip and knee angular displacements and velocities were also synchronously recorded using a motion capture system. We found that the L-Protocol elicits a maximal contraction (up to 60% of the MVC in the glider exercise) in the hamstring muscles at a work point similar to the swing phase of running (around 62 degrees hip flexion and 23 degrees knee flexion). No difference in the levels of activation of the hamstrings was observed between the diver and glider, regardless of the different functional role they had in the two exercises. During the extender, the hamstring muscles are stretched and minimally engaged. Finally, co-activation analysis highlighted that through the combination of passive stretch and active eccentric contraction, the hamstrings are trained to co-activate using similar structural modules employed differentially to drive the movement or stabilize it.

THE REHABILITATION OF A RUNNER WITH ILIOPSOAS TENDINOPATHY USING AN ECCENTRIC-BIASED EXERCISE-A CASE REPORT

Background and Purpose

While there is much discussion about tendinopathy in the literature, there is little reference to the less common condition of iliopsoas tendinopathy, and no documentation of the condition in runners. The iliopsoas is a major decelerator of the hip and eccentric loading of the iliopsoas is an important component of energy transfer during running. Eccentric training is a thoroughly researched method of treating tendinopathy but has shown mixed results. The purpose of this case report is to describe the rehabilitation of a runner with iliopsoas tendinopathy, and demonstrate in a creative eccentric-biased technique to assist with treatment. A secondary objective is to illustrate how evidence on intervention for other tendinopathies was used to guide rehabilitation of this seldom described condition.

Case Description

The subject was a 39-year-old female middle distance runner diagnosed with iliopsoas tendinopathy via ultrasound, after sudden onset of left anterior groin pain. Symptoms began after a significant increase in running load, and persisted, despite rest, for three months. The intervention consisted of an eccentric-biased hip flexor exercise, with supportive kinetic chain exercises and progressive loading in a return to running program.

Outcomes

The Copenhagen Hip and Groin Outcome Score, the Visual Analogue Scale, the Global Rating of Change Scale and manual muscle testing scores all improved after 12 weeks of intervention with further improvement at the five-year follow up. After 12 weeks of intervention, the subject was running without restriction and had returned to her pre-injury running mileage at the five-year follow up.

Discussion

The eccentric-biased exercise in conjunction with exercises addressing the kinetic chain and a progressive tendon loading program, were successful in the rehabilitation of this subject with iliopsoas tendinopathy. This case report is the first to provide a description on the rehabilitation of iliopsoas tendinopathy, and offers clinicians suggestions and guidance for treatment and exercise choice in the clinical environment.

Level of Evidence

5.

The Potential for a Targeted Strength-Training Program to Decrease Asymmetry and Increase Performance: A Proof of Concept in Sprinting

The global application of horizontal force (F_H) via hip extension is related to improvements in sprint performance (eg, maximal velocity [v_max] and power [P_max]). Little is known regarding the contribution of individual leg F_H and how a difference between the legs (asymmetry) might subsequently affect sprint performance. The authors assessed a single male athlete for pre-post outcomes of a targeted hip-extension training program on F_H asymmetry and sprint-performance metrics. An instrumented nonmotorized treadmill was used to obtain individual leg and global sprint kinetics and determine the athlete's strong and weak leg, with regard to the ability to produce F_H while sprinting. Following a 6-wk control block of testing, a 6-wk targeted training program was added to the athlete's strength-training regimen, which aimed to strengthen the weak leg and improve hip-extension function during sprinting. Preintervention to postintervention, the athlete increased F_H (standardized effect [ES] = 2.2; +26%) in his weak leg, decreased the F_H asymmetry (ES = -0.64; -19%), and increased v_max (ES = 0.67; +2%) and P_max (ES = 3.2; +15%). This case study highlighted a promising link between a targeted training intervention to decrease asymmetry in F_H and subsequent improvement of sprint-performance metrics. These findings also strengthen the theoretical relationship between the contribution of individual leg F_H and global F_H while sprinting, indicating that reducing asymmetry may decrease injury risk and increase practical performance measures. This case study may stimulate further research investigating targeted training interventions in the field of strength and conditioning and injury prevention.

Effectiveness of a Home-Based Eccentric-Exercise Program on the Torque-Angle Relationship of the Shoulder External Rotators: A Pilot Study

CONTEXT

The role of the rotator cuff is to provide dynamic stability to the glenohumeral joint. Human and animal studies have identified sarcomerogenesis as an outcome of eccentric training indicated by more torque generation with the muscle in a lengthened position.

OBJECTIVE

The authors hypothesized that a home-based eccentric-exercise program could increase the shoulder external rotators' eccentric strength at terminal internal rotation (IR).

DESIGN

Prospective case series.

SETTING

Clinical laboratory and home exercising.

PARTICIPANTS

10 healthy subjects (age 30 ± 10 y).

INTERVENTION

All participants performed 2 eccentric exercises targeting the posterior shoulder for 6 wk using a home-based intervention program using side-lying external rotation (ER) and horizontal abduction.

MAIN OUTCOME MEASURES

Dynamic eccentric shoulder strength measured at 60°/s through a 100° arc divided into 4 equal 25° arcs (ER 50-25°, ER 25-0°, IR 0-25°, IR 25-50°) to measure angular impulse to represent the work performed. In addition, isometric shoulder ER was measured at 5 points throughout the arc of motion (45° IR, 30° IR, 15° IR, 0°, and 15° ER). Comparison of isometric and dynamic strength from pre- to posttesting was evaluated with a repeated-measure ANOVA using time and arc or positions as within factors.

RESULTS

The isometric force measures revealed no significant differences between the 5 positions (P = .56). Analysis of the dynamic eccentric data revealed a significant difference between arcs (P = .02). The percentage-change score of the arc of IR 25-50° was found to be significantly greater than that of the arc of IR 0-25° (P = .007).

CONCLUSION

After eccentric training the only arc of motion that had a positive improvement in the capacity to absorb eccentric loads was the arc of motion that represented eccentric contractions at the longest muscle length.

Determining return-to-sport status with a multi-component assessment strategy: a case study in rugby

BACKGROUND

The effectiveness of rehabilitation programmes are often distorted by the athlete's desire to return and can result in injury recurrence. Athletic assessments allow for objective and reliable measurements to track rehabilitation progress. This case study used a multi-component assessment strategy to assess a rugby player's lower-extremity strength and symmetry as a primary determinate of their return-to-sport status.

CASE DESCRIPTION

A professional rugby league player was assessed for lower-extremity isokinetic strength and sprint kinetics pre- and 10-weeks post-rehabilitation programme following two consecutive knee injuries involving surgical intervention.

OUTCOMES

Pre-testing analysis showed clinical and functional strength deficits in the injured leg as high as 34% compared to the non-injured leg. Pre- to post-testing showed: increases in peak torque (49%) and decreased asymmetries by 50%; unilateral horizontal force increased (injured: 50%, non-injured: 19%) during sprinting; force production asymmetries decreased up to 18%.

DISCUSSION

The rugby player showed clinical and functional strength deficiencies return to normal ranges following a rehabilitation programme. A return-to-sport decision was made by the athlete's supporting health team based on the sizeable asymmetry decreases and return-to-normative ranges for knee and hip strength and sprint kinetics. The athlete returned to the 2013 National Rugby League season without any major injuries.

Soccer-specific warm-up and lower extremity injury rates in collegiate male soccer players

CONTEXT

A number of comprehensive injury-prevention programs have demonstrated injury risk-reduction effects but have had limited adoption across athletic settings. This may be due to program noncompliance, minimal exercise supervision, lack of exercise progression, and sport specificity. A soccer-specific program described as the F-MARC 11+ was developed by an expert group in association with the Federation Internationale de Football Association (FIFA) Medical Assessment and Research Centre (F-MARC) to require minimal equipment and implementation as part of regular soccer training. The F-MARC 11+ has been shown to reduce injury risk in youth female soccer players but has not been evaluated in an American male collegiate population.

OBJECTIVE

To investigate the effects of a soccer-specific warm-up program (F-MARC 11+) on lower extremity injury incidence in male collegiate soccer players.

DESIGN

Cohort study.

SETTING

One American collegiate soccer team followed for 2 seasons.

PATIENTS OR OTHER PARTICIPANTS

Forty-one male collegiate athletes aged 18-25 years.

INTERVENTION(S)

The F-MARC 11+ program is a comprehensive warm-up program targeting muscular strength, body kinesthetic awareness, and neuromuscular control during static and dynamic movements. Training sessions and program progression were monitored by a certified athletic trainer.

MAIN OUTCOME MEASURE(S)

Lower extremity injury risk and time lost to lower extremity injury.

RESULTS

The injury rate in the referent season was 8.1 injuries per 1000 exposures with 291 days lost and 2.2 injuries per 1000 exposures and 52 days lost in the intervention season. The intervention season had reductions in the relative risk (RR) of lower extremity injury of 72% (RR = 0.28, 95% confidence interval = 0.09, 0.85) and time lost to lower extremity injury (P < .01).

CONCLUSIONS

This F-MARC 11+ program reduced overall risk and severity of lower extremity injury compared with controls in collegiate-aged male soccer athletes.

The management of bilateral high hamstring tendinopathy with ASTYM® treatment and eccentric exercise: a case report

High hamstring tendinopathy (HHT) is an overuse injury that occurs most commonly in runners. The management of HHT is often challenging and the research supporting many interventions is limited. Eccentric exercise has been proven effective in the treatment of various tendinopathies but has not been thoroughly studied with HHT. Soft tissue mobilization, including ASTYM, is often utilized in the treatment of tendinopathies, though there is limited evidence supporting this approach. The purpose of this paper is to present the case of a patient referred to physical therapy with bilateral HHT. The patient was a 41-year-old recreational runner that had an insidious onset of right buttock pain 12 months prior to initiating therapy and left buttock pain 9 months prior. Her primary complaints included an inability to run, pain with prolonged or brisk walking, and pain with sitting on hard surfaces. The patient was treated in physical therapy two times per week for 16 visits with treatment focused on eccentric hamstring strengthening and ASTYM. By her eighth visit, the patient was able to walk 2·5 miles without pain and by her 12 visit, she was able to jog 1 mile before the onset of pain. After 16 visits, the patient reported that she was approximately 95% improved, was able to run 2·5 miles without pain, and had no pain with sitting on hard surfaces. This case suggests that eccentric exercise combined with ASTYM may be an effective treatment for HHT.

Influence of hip-flexion angle on hamstrings isokinetic activity in sprinters

CONTEXT

Hamstrings strains are common and debilitating injuries in many sports. Most hamstrings exercises are performed at an inadequately low hip-flexion angle because this angle surpasses 70° at the end of the sprinting leg's swing phase, when most injuries occur.

OBJECTIVE

To evaluate the influence of various hip-flexion angles on peak torques of knee flexors in isometric, concentric, and eccentric contractions and on the hamstrings-to-quadriceps ratio.

DESIGN

Descriptive laboratory study.

SETTING

Research laboratory.

PATIENTS AND OTHER PARTICIPANTS

Ten national-level sprinters (5 men, 5 women; age = 21.2 ± 3.6 years, height = 175 ± 6 cm, mass = 63.8 ± 9.9 kg).

INTERVENTION(S)

For each hip position (0°, 30°, 60°, and 90° of flexion), participants used the right leg to perform (1) 5 seconds of maximal isometric hamstrings contraction at 45° of knee flexion, (2) 5 maximal concentric knee flexion-extensions at 60° per second, (3) 5 maximal eccentric knee flexion-extensions at 60° per second, and (4) 5 maximal eccentric knee flexionextensions at 150° per second.

MAIN OUTCOME MEASURE(S)

Hamstrings and quadriceps peak torque, hamstrings-to-quadriceps ratio, lateral and medial hamstrings root mean square.

RESULTS

We found no difference in quadriceps peak torque for any condition across all hip-flexion angles, whereas hamstrings peak torque was lower at 0° of hip flexion than at any other angle (P < .001) and greater at 90° of hip flexion than at 30° and 60° (P < .05), especially in eccentric conditions. As hip flexion increased, the hamstrings-to-quadriceps ratio increased. No difference in lateral or medial hamstrings root mean square was found for any condition across all hip-flexion angles (P > .05).

CONCLUSIONS

Hip-flexion angle influenced hamstrings peak torque in all muscular contraction types; as hip flexion increased, hamstrings peak torque increased. Researchers should investigate further whether an eccentric resistance training program at sprint-specific hip-flexion angles (70° to 80°) could help prevent hamstrings injuries in sprinters. Moreover, hamstrings-to-quadriceps ratio assessment should be standardized at 80° of hip flexion.

Recurrent hamstring muscle injury: applying the limited evidence in the professional football setting with a seven-point programme

Recurrent hamstring injuries are a major problem in sports such as football. The aim of this paper was to use a clinical example to describe a treatment strategy for the management of recurrent hamstring injuries and examine the evidence for each intervention. A professional footballer sustained five hamstring injuries in a relatively short period of time. The injury was managed successfully with a seven-point programme—biomechanical assessment and correction, neurodynamics, core stability, eccentric strengthening, an overload running programme, injection therapies and stretching/relaxation. The evidence for each of these treatment options is reviewed. It is impossible to be definite about which aspects of the programme contributed to a successful outcome. Only limited evidence is available in most cases; therefore, decisions regarding the use of different treatment modalities must be made by using a combination of clinical experience and research evidence.

Absolute reliability of isokinetic knee flexion and extension measurements adopting a prone position

The main purpose of this study was to determine the absolute and relative reliability of isokinetic peak torque (PT), angle of peak torque (APT), average power (PW) and total work (TW) for knee flexion and extension during concentric and eccentric actions measured in a prone position at 60, 180 and 240° s(-1). A total of 50 recreational athletes completed the study. PT, APT, PW and TW for concentric and eccentric knee extension and flexion were recorded at three different angular velocities (60, 180 and 240° s(-1)) on three different occasions with a 72- to 96-h rest interval between consecutive testing sessions. Absolute reliability was examined through typical percentage error (CV(TE)), percentage change in the mean (ChM) and relative reliability with intraclass correlations (ICC(3,1)). For both the knee extensor and flexor muscle groups, all strength data (except APT during knee flexion movements) demonstrated moderate absolute reliability (ChM < 3%; ICCs > 0·70; and CV(TE) < 20%) independent of the knee movement (flexion and extension), type of muscle action (concentric and eccentric) and angular velocity (60, 180 and 240° s(-1)). Therefore, the current study suggests that the CV(TE) values reported for PT (8-20%), APT (8-18%) (only during knee extension movements), PW (14-20%) and TW (12-28%) may be acceptable to detect the large changes usually observed after rehabilitation programmes, but not acceptable to examine the effect of preventative training programmes in healthy individuals.

Selective strength loss and decreased muscle activity in hamstring injury

STUDY DESIGN

Cross-sectional, controlled laboratory study.

OBJECTIVES

To determine whether thigh muscle isokinetic torque patterns and activity, measured by electromyography (EMG), of individuals with hamstring injury differ from control individuals.

BACKGROUND

Neuromuscular control during thigh muscle strength assessment following hamstring injuries has not been reported.

METHODS

Fifteen athletes with prior hamstring injury (hamstring-injured group [HG]) were compared to 15 uninjured athletes (control group [CG]). The injuries were incurred 6 weeks to 12 months prior to participation, and all injured athletes had returned to at least partial training. Participants performed 5 isokinetic concentric extensor, concentric flexor, and eccentric flexor torque tests at 60°/s in the seated position. Peak torque was determined for each contraction type, as well as average torque for each of 4 time-based movement quartiles. EMG root-mean-squares were calculated in these movement quartiles for the biceps femoris and medial hamstrings.

RESULTS

No significant differences were found for peak torque for all contractions, when comparing HG injured and uninjured sides to CG bilateral averages. The HG injured limb eccentric flexor torque was significantly lower in the fourth quartile (approximately 25° to 5° knee flexion, hamstring lengthened range) compared to the CG bilateral average (P = .025). Eccentric flexor biceps femoris and hamstrings EMG root-mean-squares of the HG injured and the uninjured sides were significantly lower in the second to fourth quartiles (towards the lengthened range), compared to the CG bilateral averages (P<.05).

CONCLUSION

Decreased strength and EMG activation in a lengthened hamstrings range for the athletes with prior hamstring injury suggested a change in neuromuscular control. Lengthened range assessment of isokinetic eccentric flexor torque may be useful for the assessment of athletes with a prior injury; however, results should be confirmed with prospective studies.