The Use of Eccentric Training and Stretching in the Treatment and Prevention of Tendon Injuries

Probing nanoscale structural response of collagen fibril in human Achilles tendon during loading using in situ SAXS

The specific viscoelastic mechanical properties of the human Achilles tendon are strongly dependent on the structural characteristics of collagen. Although research on the deformation mechanisms of the Achilles tendon in various animals is extensive, understanding of these mechanisms in the human Achilles tendon remains largely empirical and macroscopic. In this work, the evolution of D-space, orientation, and average length of voids between fibers are investigated during the stretching using SAXS techniques. Initially, the void length increases marginally, while the misorientation breadth decreased rapidly as the D-space steadily increased. In the second region, D-space and the void length increase sharply under rising stress, even though misorientation width decreased. During the third region, the increases in void length and D-space decelerate, but the misorientation width widens, suggesting the onset of irreversible microscopic fibril failure in the Achilles tendon. In the final region, the fibers undergo macroscopic failure, with D-space and void length returning to their initial states. The macroscopic alterations are elucidated by the nanoscale structural responses, providing a fundamental understanding of the mechanisms driving the complex biomechanics, tissue structural organization, and Achilles tendon regeneration.

Effects of Collagen and Exercise on Tendon Properties and Pain: A Critically Appraised Topic

CLINICAL SCENARIO

Achilles tendon ruptures are prevalent and devastating injuries that require the need for extensive rehabilitation. The methods for preventing these injuries vary between different exercise methods and nutritional supplementation. Although proven effective for decreasing pain and increasing tendon properties, the influence of these 2 methods in combination has not yet been evaluated.

CLINICAL QUESTION

Does exercise combined with collagen supplementation improve Achilles tendon structural and mechanical properties and diminish subsequent patient-reported pain compared with exercise alone in adults?

SUMMARY OF KEY FINDINGS

Exercise training, including eccentric training protocols and concentric resistance training protocols, combined with collagen supplementation influence Achilles tendon properties and subsequent patient-reported pain compared with exercise alone.

CLINICAL BOTTOM LINE

Evidence supports that collagen along with exercise training has a significant influence on pain mitigation, augmented cross-sectional area, and tendon thickness, but may have little to no influence on tendon stiffness and microvascularity compared with exercise alone. Further research is needed to determine the effects of combined methods on various populations.

STRENGTH OF RECOMMENDATION

Collectively, the body of evidence included to answer the clinical question aligns with the strength of recommendation of A.

A Review of Physiotherapy Techniques Used in the Treatment of Tennis Elbow

Tennis elbow, a common musculoskeletal disorder also known as lateral epicondylitis, causes pain and tenderness on the outside of the elbow. Although it is frequently linked to repetitive motions, such as those in racquet sports, it can affect people in a variety of occupations and activities. Tennis elbow can be treated conservatively with physiotherapy, which focuses on pain management, functional recovery, and recurrence prevention. The goal of this review is to give a thorough overview of the physiotherapy methods used to treat tennis elbow. In order to determine the most effective treatment options, it is crucial to comprehend the pathophysiology and etiology of tennis elbow from the outset of the study. The assessment and diagnosis of tennis elbow are next covered, emphasizing the importance of physiotherapists in correctly diagnosing the ailment and distinguishing it from other musculoskeletal problems that are comparable to it. This study primarily focuses on the numerous physiotherapy therapies for tennis elbow, which may include but are not limited to, and the section examines the use of manual treatments to treat pain and enhance joint function, including joint mobilizations, soft tissue massage, and myofascial release. Exercise rehabilitation covers the value of tailored workouts to bolster the weak muscles and enhance the elbow joint's biomechanics. Numerous workout regimens are covered, such as eccentric training and progressive resistance exercises, as well as modalities. Therapeutic agents frequently make use of modalities such as ultrasound, laser therapy, and cryotherapy. It may also make use of complementary therapeutic agents such as taping and bracing. In summary, this in-depth analysis highlights the crucial role that physical therapy plays in the treatment of tennis elbow. It seeks to give practitioners a useful tool for enhancing the care and results of patients with this common and crippling ailment by summarizing the most recent research and best practices in physiotherapy approaches.

The use of physical function capacity measures in the management of lower limb tendinopathy: A scoping review of expert recommendations

BACKGROUND

Physical function capacity measures are recommended as outcome measures for people with lower limb tendinopathy.

OBJECTIVE

(i) Explore measures of physical function capacity recommended by experts in lower limb tendinopathy (ii) the context they were used, (ii) identify recommended criteria for exercise progression and return to sport or activity.

DESIGN

Scoping Review.

METHOD

Three databases were searched using keywords for lower limb tendinopathy and physical function capacity to identify studies that outlined a progressive exercise rehabilitation program. A 15-item tool was used for data extraction.

RESULTS

26 studies were included, only eight recommended a physical function capacity measure. There were 10 physical function capacity measures identified for a range of lower limb tendinopathies including patellar (50%), Achilles (13%), proximal hamstring (13%), gluteal (13%), combined patellar and Achilles (13%). Pain was the most common criterion that was used to determine the progression of rehabilitation (96%), with physical function capacity measures rarely used (12%).

CONCLUSION

Physical function capacity measures are used infrequently across expert recommended exercise rehabilitation programs. There remains a high reliance on pain as the criterion for progression of exercises during rehabilitation. There is a need to develop measures of physical function capacity to better inform and progress rehabilitation.

Check-rein technique for Achilles tendon elongation following conservative management for acute Achilles tendon ruptures: a two-year prospective clinical study

Background

Following conservative management for acute Achilles tendon (AT) ruptures, the tendon may heal in continuity, and some patients may present with an elongated Achilles tendon–gastrosoleus complex. This study investigated the efficacy and feasibility of a novel minimally invasive technique, which we named “check-rein procedure”, in patients with intact and elongated AT following conservative management for AT ruptures.

Methods

All patients who underwent the check-rein procedure for elongation of the gastrosoleus–AT complex by one experienced surgeon were prospectively enrolled. The AT resting angle (ATRA) and AT rupture score (ATRS) were assessed at baseline and repeated at 2-year follow-up, as were calf circumference and isometric plantarflexion strength of both ankles.

Results

Forty-three patients (43 procedures) were analysed. The mean time elapsed from injury to surgery was 28.7 ± 7.9 weeks. The mean age at surgery was 38.5 ± 5.7 years. At the last follow-up, ATRS, ATRA, isometric strength difference, and calf circumference of the affected side were increased (P < 0.0001). The rate of the return to sport was 98% (42 of 43). No wound complications or rupture were experienced by any patient.

Conclusion

The check-rein technique for AT elongation after conservative management of AT tears is effective and feasible to restore tendon length and calf function. The surgical outcome was influenced by the preoperative performance status, and longer time elapsed from injury to surgery worsens the outcomes.

Maximum dorsiflexion increases Achilles tendon force during exercise for midportion Achilles tendinopathy

Rehabilitation is an important treatment for non-insertional Achilles tendinopathy. To date, eccentric loading exercises (ECC) have been the predominant choice; however, mechanical evidence underlying their use remains unclear. Other protocols, such as heavy slow resistance loading (HSR), have shown comparable outcomes, but with less training time. This study aims to identify the effect of external loading and other variables that influence Achilles tendon (AT) force in ECC and HSR. Ground reaction force and kinematic data during ECC and HSR were collected from 18 healthy participants for four loading conditions. The moment arms of the AT were estimated from MRIs of each participant. AT force then was calculated using the ankle torque obtained from inverse dynamics. In the eccentric phase, the AT force was not larger than in the concentric phase in both ECC and HSR. Under the same external load, the force through the AT was larger in ECC with the knee bent than in HSR with the knee straight due to increased dorsiflexion angle of the ankle. Multivariate regression analysis showed that external load and maximum dorsiflexion angle were significant predictors of peak AT force in both standing and seated positions. Therefore, to increase the effectiveness of loading the AT, exercises should apply adequate external load and reach maximum dorsiflexion during the movement. Peak dorsiflexion angle affected the AT force in a standing position at twice the rate of a seated position, suggesting standing could prove more effective for the same external loading and peak dorsiflexion angle.

In Vitro Innovation of Tendon Tissue Engineering Strategies

Tendinopathy is the term used to refer to tendon disorders. Spontaneous adult tendon healing results in scar tissue formation and fibrosis with suboptimal biomechanical properties, often resulting in poor and painful mobility. The biomechanical properties of the tissue are negatively affected. Adult tendons have a limited natural healing capacity, and often respond poorly to current treatments that frequently are focused on exercise, drug delivery, and surgical procedures. Therefore, it is of great importance to identify key molecular and cellular processes involved in the progression of tendinopathies to develop effective therapeutic strategies and drive the tissue toward regeneration. To treat tendon diseases and support tendon regeneration, cell-based therapy as well as tissue engineering approaches are considered options, though none can yet be considered conclusive in their reproduction of a safe and successful long-term solution for full microarchitecture and biomechanical tissue recovery. In vitro differentiation techniques are not yet fully validated. This review aims to compare different available tendon in vitro differentiation strategies to clarify the state of art regarding the differentiation process.

Tendon lengthening after achilles tendon rupture-passive effects on the ankle joint in a cadaveric pilot study simulating weight bearing

BACKGROUND

In recent years, primary Achilles tendon ruptures have increased due to the aging population's participation in physically demanding activities. These injuries commonly occur during recreational sports and frequently lead to a long-term reduction in activity despite treatment. Non-operative methods of treatment for Achilles tendon ruptures may result in the Achilles healing in a lengthened position compared to the pre-injury state. This study uses a cadaveric model that simulates static weight bearing to explore the effect of a lengthened Achilles tendon on ankle joint load distribution.

METHODS

Five lower limb cadaveric specimens were placed on a custom jig, where a 334 N (75 lb) load was applied at the femoral head, and the foot was supported against a plate to simulate static double-leg stance. A pressure mapping sensor was inserted into the ankle joint. A percutaneous triple hemiresection tendo-Achilles lengthening procedure (Hoke procedure) was performed on each specimen to simulate tendon lengthening after conservative treatment. Contact pressure, peak pressure, and center-of-pressure were measured for native and tendon-lengthened conditions.

RESULTS

Tendon rupture did not significantly alter average contact pressure, peak contact pressures, or center-of-pressure in the ankle joint compared with native tendon.

CONCLUSION

Achilles lengthening does not significantly change contact pressures of the ankle joint in this model . This result suggests that the passive restraint on ankle joint translation imposed by the Achilles tendon is minimal without muscle activation.

Effects of flexibility and strength interventions on optimal lengths of hamstring muscle-tendon units

OBJECTIVES

The aim of the present study was to determine the effects of altering both hamstring flexibility and strength on hamstring optimal lengths.

DESIGN

Controlled laboratory study.

METHODS

A total of 20 male and 20 female college students (aged 18-24 years) participated in this study and were randomly assigned to either a flexibility intervention group or a strength intervention group. Passive straight leg raise and isokinetic strength test were performed before and after interventions. Paired T-tests were performed to determine hamstring flexibility or strength intervention effects on hamstring optimal lengths.

RESULTS

Male participants in the flexibility intervention group significantly increased range of hip joint flexion (P=0.001) and optimal lengths of semimembranosus and biceps long head (P≤0.026). Male participants in the strength intervention group significantly increased hamstring strength (P=0.001), the range of hip joint flexion (P=0.037), and optimal lengths of all three bi-articulated hamstring muscles (P≤0.041). However, female participants did not significantly increase their hamstring optimal lengths in either intervention groups (P≥0.097) although both groups significantly increased the range of hip joint flexion and strength (P≤0.009).

CONCLUSION

Hamstring optimal lengths can be modified through flexibility intervention as well as strength intervention for male participants, but not for female participants in this study. Hamstring optimal lengths should be considered as hamstring flexibility measures in future prospective studies to identify potentially modifiable risk factors for hamstring injury.

Proximal Plantar Intrinsic Tendinopathy: Anatomical and Biomechanical Considerations in Plantar Heel Pain

Plantar heel pain is often managed through podiatric and physical therapy interventions. Numerous differential diagnoses may be implicated in patients presenting with plantar heel pain; however, symptoms are often attributed to plantar fasciitis. Abductor hallucis, flexor digitorum brevis, and quadratus plantae share proximal anatomic attachment sites and mechanical function with the plantar fascia. Although these plantar intrinsic muscles each perform isolated digital actions based on fiber orientation and attachment sites, they function collectively to resist depression of the lateral and medial longitudinal arches of the foot. Overuse injury is the primary contributing factor in tendinopathy. The close anatomic proximity and mechanical function of these muscles relative to the plantar fascia suggests potential for proximal plantar intrinsic tendinopathy as a result of repetitive loading during gait and other weightbearing activities. To date, this diagnosis has not been proposed in the scientific literature. Future studies should seek to confirm or refute the existence of proximal plantar intrinsic tendinopathic changes in patients with acute and chronic plantar heel pain through diagnostic imaging studies, analysis of lactate concentration in pathologic versus nonpathologic tendons, and response to specific podiatric and physical therapy interventions germane to tendinopathy of these muscles.

Sex Differences in Mechanical Properties of the Achilles Tendon: Longitudinal Response to Repetitive Loading Exercise

Lepley, AS, Joseph, MF, Daigle, NR, Digiacomo, JE, Galer, J, Rock, E, Rosier, SB, and Sureja, PB. Sex differences in mechanical properties of the Achilles tendon: Longitudinal response to repetitive loading exercise. J Strength Cond Res 32(11): 3070-3079, 2018-Sex differences have been observed in the mechanical properties of the Achilles tendon, which may help to explain the increased risk of injury in men. However, the response and recovery of tendon mechanics to repetitive loading exercise, as well as sex-dependent responses, are not well understood. The purpose of our study was to compare Achilles tendon mechanical properties between men and women before, immediately after, and 60 minutes after a repetitive loading exercise. Seventeen female (age: 24.0 ± 3.9 years; height: 167.4 ± 6.9 cm; and mass: 64.9 ± 8.5 kg) and 18 male (age: 23.9 ± 2.4 years; height: 179.2 ± 5.09 cm; and mass: 78.4 ± 8.7 kg) recreationally active individuals volunteered. Using isokinetic dynamometry and diagnostic ultrasound, baseline levels of Achilles tendon force, elongation, stiffness, stress, strain, and Young's modulus were assessed before 100 successive calf-raise exercises using a Smith machine at 20% of participant body mass. Outcomes were reassessed immediately and 60 minutes after exercise. Women exhibited less Achilles tendon force, stiffness, stress, and modulus compared with men, regardless of time point. Both sexes responded to repetitive loading exercise similarly, with immediate decreases in mechanical properties of the Achilles tendon from baseline to immediately after exercise. Tendon properties were observed to be equal to baseline values at 60-minute postexercise. Baseline differences in tendon properties may help to explain the disparity in injury risk because both sexes responded to and recovered from exercise similarly. Future research should aim to include additional time points (both leading up to and after 60 minutes), and assess tendon responses to more sport-specific activities, while also including patients diagnosed with Achilles tendon injuries.

Effect of wrist and finger flexion in relation to strain on the tendon origin of the extensor carpi radialis brevis: A cadaveric study simulating stretching exercises

BACKGROUND

Stretching exercises based on wrist flexion-ulnar deviation with elbow extension, forearm pronation, and additional index or middle finger flexion have been used to stretch the wrist extensors for lateral epicondylitis. The purpose of this study was to quantify the strain on the tendon origin of the extensor carpi radialis brevis in cadaver specimens during these stretching exercises.

METHODS

We used 8 fresh frozen/thawed cadaveric upper extremities. The strain on the extensor carpi radialis brevis tendon origin was measured by the addition of 4 types of traction (no traction, wrist flexion-ulnar deviation, and index or middle finger flexion in combination with wrist flexion-ulnar deviation) in 7 sequential elbow flexion angles during forearm pronation. Two types of varus stress load to the elbow (none, gravity on the forearm) were also applied.

FINDINGS

A significant increase in strain was obtained by wrist traction with 0°, 15° and 30° of elbow flexion (P<0.05). The strain was also significantly increased by adding finger traction (P<0.05) and varus stress load (P<0.05). A maximum strain value of 5.30 (SD 1.73) % was obtained when traction on the middle finger in combination with traction of the wrist was added at 15° elbow flexion with varus stress load.

INTERPRETATION

The present study provides data about the amount of strain on the extensor carpi radialis brevis tendon during stretching exercises of the wrist and finger extensors. The results of this study could be applied to stretching exercises for patients with lateral epicondylitis.

Changes in pain, dysfunction, and grip strength of patients with acute lateral epicondylitis caused by frequency of physical therapy: a randomized controlled trial

[Purpose] The purpose of this study was to investigate the changes in pain, dysfunction, and grip strength of patients with acute lateral epicondylitis and to suggest the appropriate treatment frequency and period. [Subjects] The subjects were divided into three: 2 days per week group (n=12), 3 days per week group (n=15), and 6 days per week group (n=13). [Methods] All groups received conventional physical therapy for 40 minutes and therapeutic exercises for 20 minutes per session during 6 weeks. The outcome measurements were the visual analogue scale (VAS), Patient-Rated Tennis Elbow Evaluation (PRTEE), and grip strength. [Results] The results of this study were as follows: at 3 weeks, there were no significant differences in VAS and PRTEE in the 3 groups, but at 6 weeks, 6 days per week group significantly decreased these two outcomes. Grip strength was significantly increased in 3 and 6 days per week groups at 6 weeks. [Conclusion] In conclusion, physical therapy is needed 3 days per week for 3 weeks in patients with acute lateral epicondylitis. After 3 weeks, 6 days per week is the most effective treatment frequency.

The role of mechanical loading in tendon development, maintenance, injury, and repair

Tendon injuries often result from excessive or insufficient mechanical loading, impairing the ability of the local tendon cell population to maintain normal tendon function. The resident cell population composing tendon tissue is mechanosensitive, given that the cells are able to alter the extracellular matrix in response to modifications of the local loading environment. Natural tendon healing is insufficient, characterized by improper collagen fibril diameter formation, collagen fibril distribution, and overall fibril misalignment. Current tendon repair rehabilitation protocols focus on implementing early, well-controlled eccentric loading exercises to improve repair outcome. Tissue engineers look toward incorporating mechanical loading regimens to precondition cell populations for the creation of improved biological augmentations for tendon repair.

Effects of eccentric training on mechanical properties of the plantar flexor muscle-tendon complex

Eccentric training is a mechanical loading classically used in clinical environment to rehabilitate patients with tendinopathies. In this context, eccentric training is supposed to alter tendon mechanical properties but interaction with the other components of the muscle-tendon complex remains unclear. The aim of this study was to determine the specific effects of 14 wk of eccentric training on muscle and tendon mechanical properties assessed in active and passive conditions in vivo. Twenty-four subjects were randomly divided into a trained group (n = 11) and a control group (n = 13). Stiffness of the active and passive parts of the series elastic component of plantar flexors were determined using a fast stretch during submaximal isometric contraction, Achilles tendon stiffness and dissipative properties were assessed during isometric plantar flexion, and passive stiffness of gastrocnemii muscles and Achilles tendon were determined using ultrasonography while ankle joint was passively moved. A significant decrease in the active part of the series elastic component stiffness was found (P < 0.05). In contrast, a significant increase in Achilles tendon stiffness determined under passive conditions was observed (P < 0.05). No significant change in triceps surae muscles and Achilles tendon geometrical parameters was shown (P > 0.05). Specific changes in muscle and tendon involved in plantar flexion are mainly due to changes in intrinsic mechanical properties of muscle and tendon tissues. Specific assessment of both Achilles tendon and plantar flexor muscles allowed a better understanding of the functional behavior of the muscle-tendon complex and its adaptation to eccentric training.

Eccentric strengthening effect of hip-adductor training with elastic bands in soccer players: a randomised controlled trial

BACKGROUND

Soccer players with weak hip-adductor muscles are at increased risk of sustaining groin injuries. Therefore, a simple hip-adductor strengthening programme for prevention of groin injuries is needed.

OBJECTIVE

We aimed to investigate the effect of an 8-week hip-adductor strengthening programme, including one hip-adduction exercise, on eccentric and isometric hip-adduction strength, using elastic bands as external load.

METHODS

Thirty-four healthy, sub-elite soccer players, mean (±SD) age of 22.1 (±3.3) years, were randomised to either training or control. During the mid-season break, the training group performed 8 weeks of supervised, progressive hip-adduction strength training using elastic bands. The participants performed two training sessions per week (weeks 1-2) with 3×15 repetition maximum loading (RM), three training sessions per week (weeks 3-6) with 3×10 RM and three training sessions per week (weeks 7-8) with 3×8 RM. Eccentric hip-adduction (EHAD), isometric hip-adduction (IHAD) and isometric hip-abduction (IHAB) strength, and the IHAD/IHAB ratio were measured assessor-blinded preintervention and postintervention, using reliable hand-held dynamometry procedures.

RESULTS

In the training group, EHAD strength increased by 30% (p<0.001). In the control group, EHAD strength increased by 17% (p<0.001), but the increase was significantly larger in the training group compared with the control group (p=0.044). No other significant between-group strength-differences in IHAD, IHAB or the IHAD/IHAB ratio existed (p>0.05).

CONCLUSIONS

8 weeks of hip-adduction strength training, using elastic bands, induce a relevant increase in eccentric hip-adduction strength in soccer players, and thus may have implications as a promising approach towards prevention of groin injuries in soccer.

Continued significant effect of physical training as treatment for overuse injury: 8- to 12-year outcome of a randomized clinical trial

BACKGROUND

The treatment of exercise-related injuries is often a problem, and recurrent injuries are common. Two recent systematic reviews found only one high-quality paper on the treatment of long-standing groin pain. In this randomized clinical trial, a training program including strength training resulted in a return of 79% of the athletes to the previous level of sport without any groin pain. The long-term effect of this exercise program was evaluated.

HYPOTHESIS

The effect of the exercise program for adductor-related groin pain is long lasting.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Forty-seven (80%) of the 59 original participants of the study agreed to participate in this 8- to 12-year follow-up. They were all interviewed and examined using a standardized and reproducible protocol, identical to the one used in the original trial. The investigating physician (P.N.) was not involved in the original study and was unaware of the original treatment allocation.

RESULTS

A significant effect of the active training treatment still existed for the whole group (P = .047) and even more for the subgroup of 39 (83%) soccer players (P = .012). No significant differences were found regarding age, present sports activity, reasons for activity reduction, or time to follow-up.

CONCLUSION

The beneficial short-term effect of the exercise program used in the primary randomized clinical trial for treating long-standing adductor-related groin pain in athletes was found to be lasting, both for the whole group and even more for the large subgroup of soccer players. This is the first time an exercise treatment for overuse injuries to the musculoskeletal system has been shown to have a long-lasting effect (8-12 years).

Exercise program for prevention of groin pain in football players: a cluster-randomized trial

Groin injuries cause major problems in sports and particularly in football. Exercise is effective in treating adductor-related groin pain, but no trials have been published regarding the specific prevention of groin pain or prevention specifically targeting overuse injuries in sport using exercise programs. We performed a cluster-randomized trial including 55 football clubs representing 1211 players. The clubs were randomized to an exercise program aimed at preventing groin injuries (n=27) or to a control group training as usual (n=28). The intervention program consisted of six exercises including strengthening (concentric and eccentric), coordination, and core stability exercises for the muscles related to the pelvis. Physiotherapists assigned to each club registered all groin injuries. Twenty-two clubs in each group completed the study, represented by 977 players. There was no significant effect of the intervention (HR=0.69, 95% CI 0.40-1.19). The risk of a groin injury was reduced by 31%, but this reduction was not significant. A univariate analysis showed that having had a previous groin injury almost doubles the risk of developing a new groin injury and playing at a higher level almost triples the risk of developing a groin injury.

Biomechanical characteristics of the eccentric Achilles tendon exercise

BACKGROUND

Eccentric exercise has been shown to provide good short-term clinical results in the treatment of painful mid-portion chronic Achilles tendinopathies. However, the mechanisms behind the positive effects of eccentric rehabilitation regimes are not known, and research into the biomechanics of the exercise may improve our understanding.

METHODS

Sixteen healthy subjects performed one-legged full weight bearing ankle plantar and dorsiflexion exercises during which three-dimensional ground reaction forces (GRF), ankle joint kinematics and surface electromyography (EMG) of the lower leg muscles were recorded. Joint kinematics, GRF frequency contents, average EMG amplitudes, and Achilles tendon loads were calculated.

FINDINGS

The eccentric movement phase was characterized by a higher GRF frequency content in the 8-12 Hz range, and reduced EMG activity in the lower leg muscles. No differences in Achilles tendon loads were found.

INTERPRETATION

This descriptive study demonstrates differences in the movement biomechanics between the eccentric and concentric phases of one-legged full weight bearing ankle dorsal and plantar flexion exercises. In particular, the findings imply that although the tendon loads are similar, the tendon is vibrated at higher frequencies during the eccentric phase than during the concentric phases. This study provides data that may explain the mechanisms behind the effectiveness of eccentric exercises used in the treatment of Achilles tendinopathies.

Early loading in physiotherapy treatment after full-thickness rotator cuff repair: a prospective randomized pilot-study with a two-year follow-up

Objective: To describe the clinical changes following two different physiotherapy treatment protocols after rotator cuff repair.

Design: A prospective, randomized pilot study with a two-year follow-up.

Subjects: Five women and nine men, 55 (40—64) years old, were included.

Intervention: The progressive group (n = 7) started with dynamic, specific muscle activation of the rotator cuff the day after surgery as well as passive range of motion. After four weeks of immobilization the loading to the rotator cuff increased and in a progressive manner throughout the rehabilitation. In the traditional group (n = 7) the rotator cuff was protected from loading. Patients were immobilized for six weeks and started with passive range of motion the day after surgery. No specific exercises to the rotator cuff were introduced during this period.

Main measures: A clinical evaluation was made preoperatively, 3, 6, 12 and 24 months after surgery. Pain rating during activity and at rest, patient satisfaction, active range of motion and muscle strength, Constant score, hand in neck, hand in back and pour out of a pot, as well as Functional Index of the Shoulder were used.

Results: At two years follow-up, the progressive group and traditional group scored pain during activity visual analogue scale (VAS) 2/0 mm and pain at rest 0/0 mm, respectively. The groups attained 170/175° in active abduction in standing and 70/90° in passive external rotation while lying in supine. Using Constant score, the groups attained 82/77 points respectively.

Conclusion: The present study showed that the progressive protocol produced no adverse effects compared with the traditional protocol.

The epidemiology of ankle injuries in professional rugby union players

BACKGROUND

Ankle injuries represent a considerable proportion of injuries to professional rugby union players; however, there is a scarcity of detailed epidemiology about these injuries.

PURPOSE

To describe the epidemiology and assess the risk factors associated with ankle injuries sustained by a cohort of professional rugby union players.

STUDY DESIGN

Descriptive epidemiology study.

METHOD

Medical personnel prospectively reported time-loss injuries in professional rugby union in England, and the ankle injuries were evaluated.

RESULTS

Lateral ankle ligament injuries were the most common injury reported during matches and training, and together with Achilles tendon injuries, they accounted for more than half of the absence due to injury. The incidence rate of injuries was highest in second-row forwards. More than a quarter of injuries were recurrences.

CONCLUSION

Lateral ankle ligament injuries and Achilles tendon injuries should be a focus of injury prevention, treatment, and rehabilitation strategies in professional rugby union players.

Early activation or a more protective regime after arthroscopic subacromial decompression — a description of clinical changes with two different physiotherapy treatment protocols — a prospective, randomized pilot study with a two-year follow-up

Objectives: To describe clinical changes with two protocols of physiotherapy following arthroscopic subacromial decompression (ASD) over two years. Reliability of Functional Index of the Shoulder was performed.

Design: A prospective, randomized pilot study, within-subject design.

Subjects: Thirty-four shoulders (13 women), mean age 46 (SD 7) years with primary shoulder impingement, listed for arthroscopic subacromial decompression.

Interventions: The traditional group (n = 20) started with active assisted range of motion exercises on the day of surgery, dynamic exercises for the rotator cuff after six weeks and strengthening exercises after eight weeks. The progressive group (n = 14) started active assisted range of motion and dynamic exercises for the rotator cuff on the day of surgery. Strengthening exercises started after six weeks.

Main measures: A clinical evaluation was made preoperatively, six weeks, three, six, 12 and 24 months after surgery. Pain, patient satisfaction, active range of motion and muscular strength were evaluated. Shoulder function was evaluated using Constant score, Hand in neck, Pour out of a pot and Functional Index of the Shoulder.

Results: Both groups showed significant improvements in pain during activity and at rest, in range of motion in extension and abduction, in strength of external rotation and in function. There were no clinical differences in changes between groups. Most patients were pain-free from six months. After two years, the majority of patients achieved ≥160°in flexion, ≥175°in abduction and 80°in external rotation, the traditional achieved 67 and the progressive group 87 with Constant score.

Conclusions: Early activation using a comprehensive, well-defined and controlled physiotherapy protocol can be used safely after arthroscopic subacromial decompression.

The mechanism for efficacy of eccentric loading in Achilles tendon injury; an in vivo study in humans

OBJECTIVE

Degenerative disorders of tendons present an enormous clinical challenge. They are extremely common, prone to recur and existing medical and surgical treatments are generally unsatisfactory. Recently eccentric, but not concentric, exercises have been shown to be highly effective in managing tendinopathy of the Achilles (and other) tendons. The mechanism for the efficacy of these exercises is unknown although it has been speculated that forces generated during eccentric loading are of a greater magnitude. Our objective was to determine the mechanism for the beneficial effect of eccentric exercise in Achilles tendinopathy.

METHODS

Seven healthy volunteers performed eccentric and concentric loading exercises for the Achilles tendon. Tendon force and length changes were determined using a combination of motion analysis, force plate data and real-time ultrasound.

RESULTS

There was no significant difference in peak tendon force or tendon length change when comparing eccentric with concentric exercises. However, high-frequency oscillations in tendon force occurred in all subjects during eccentric exercises but were rare in concentric exercises (P < 0.0001).

CONCLUSION

These oscillations provide a mechanism to explain the therapeutic benefit of eccentric loading in Achilles tendinopathy and parallels recent evidence from bone remodelling, where the frequency of the loading cycles is of more significance than the absolute magnitude of the force.

Histological analysis of achilles tendons in an overuse rat model

The purpose of this study was to design an animal model that induces histological changes in Achilles tendons consistent with those cited in the literature for human Achilles tendon disease. Sprague-Dawley rats were subjected to 10 degrees uphill treadmill running on a custom-designed rodent treadmill and at a speed of 17 meters per minute for 1 h, five times per week, over a 12-week treatment period. Subsequent histological analysis revealed alterations in the rat Achilles tendon that were generally consistent with those described in the literature for diseased human tendon tissues. These features include: decreased collagen fiber organization, more intense collagen staining, and increased cell nuclei numbers. Interestingly, though, immunohistochemical cell typing suggests that the observed increased cellularity does not include a significant inflammatory component but is secondary to increased numbers of endothelial cells (i.e., vascularization) and fibroblasts. These histological features likely represent a biological repair/remodeling response resulting from overuse running.

Effects of low-level laser therapy and eccentric exercises in the treatment of recreational athletes with chronic achilles tendinopathy

BACKGROUND

Eccentric exercises (EEs) are recommended for the treatment of Achilles tendinopathy, but the clinical effect from EE has a slow onset.

HYPOTHESIS

The addition of low-level laser therapy (LLLT) to EE may cause more rapid clinical improvement.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 52 recreational athletes with chronic Achilles tendinopathy symptoms were randomized to groups receiving either EE + LLLT or EE + placebo LLLT over 8 weeks in a blinded manner. Low-level laser therapy (lambda = 820 nm) was administered in 12 sessions by irradiating 6 points along the Achilles tendon with a power density of 60 mW/cm(2) and a total dose of 5.4 J per session.

RESULTS

The results of the intention-to-treat analysis for the primary outcome, pain intensity during physical activity on the 100-mm visual analog scale, were significantly lower in the LLLT group than in the placebo LLLT group, with 53.6 mm versus 71.5 mm (P = .0003) at 4 weeks, 37.3 mm versus 62.8 mm (P = .0002) at 8 weeks, and 33.0 mm versus 53.0 mm (P = .007) at 12 weeks after randomization. Secondary outcomes of morning stiffness, active dorsiflexion, palpation tenderness, and crepitation showed the same pattern in favor of the LLLT group.

CONCLUSION

Low-level laser therapy, with the parameters used in this study, accelerates clinical recovery from chronic Achilles tendinopathy when added to an EE regimen. For the LLLT group, the results at 4 weeks were similar to the placebo LLLT group results after 12 weeks.

Traumatic quadriceps rupture in a patient with patellectomy: a case report

INTRODUCTION

Acute traumatic, unilateral, quadriceps rupture after patellectomy is rare.

CASE PRESENTATION

We present a 42-year old male who experienced a unilateral left quadriceps tendon rupture following assault by four people. Twenty-seven years before this injury, the patient had suffered ipsilateral femur and comminuted patellar fractures, which were managed by intramedullary nailing and patellectomy respectively. We performed primary end to end repair of the torn tendon. Postoperatively, histology revealed findings consistent with pre-existent degenerative changes. The patient made good recovery, and returned to his former occupation which was reliant on his ability to drive.

CONCLUSION

Degenerative changes of the tendon of the extensor mechanism of knee following patellectomy may predispose the quadriceps tendon to traumatic rupture. Early operative intervention and protracted rehabilitation are required to obtain the best functional results.

Rehabilitation of basketball injuries

Basketball is one of the most popular sports in the United States and throughout the world, and therefore represents one of the most common sources of sports-related injuries. Basketball injuries should be managed by the same general rehabilitation principles as other sports injuries. Additionally, the clinician should be aware not only of general sports injuries but of those injuries most commonly seen in basketball players. By maintaining knowledge of the most common basketball injuries as well as their diagnosis and treatment, the clinician can help to optimize the athlete's return to play and enjoyment of the sport.

Etiology of Patellar Tendinopathy in Athletes

Objective:

To review the etiology of patellar tendinopathy as it relates to clinical management of chronic patellar-tendon disease in athletes.

Data Sources:

Information was gathered from a MEDLINE search of literature in English using the key wordspatellar tendinitis, patellar tendonitis, patellar tendinosis, patellar tendinopathy,andjumper’s knee.

Study Selection:

All relevant peer-reviewed literature in English was reviewed.

Data Synthesis:

The etiology of patellar tendinopathy is multifactorial, incorporating both intrinsic and extrinsic factors. Age, muscle flexibility, training program, and knee-joint dynamics have all been associated with patellar tendinopathy. The roles of gender, body morphology, and patellar mobility in patellar tendinopathy are unclear.

Conclusions:

The pathoetiology of patellar tendinopathy is a complex process that results from both an inflammatory response and degenerative changes. There is a tremendous need for research to improve our understanding of the pathoetiology of patellar tendinopathy and its clinical management.

The future: rehabilitation, gene therapy, optimization of healing

Tendon disorders can be debilitating for patients and are difficult to manage. Current management strategies offer symptomatic relief, but may not result in definitive disease resolution. Despite remodeling, the biochemical and mechanical properties of healed tendon tissue never match those of intact tendon. This article outlines the stages of tendon healing, and reviews the possible strategies for optimizing tendon healing and repair, such as cytokine therapy, gene therapy, and tissue engineering.

Tendinopathies in the upper extremity: a paradigm shift

Epicondylitis and de Quervain's tenosynovitis are two common diagnoses seen by hand therapists in clinical practice. Traditionally, these conditions have been viewed as being due to an inflammatory process and treated as such. New research shows that tendons exhibit areas of degeneration and a distinct lack of inflammatory cells. Tendinosis is degeneration of the collagen tissue due to aging, microtrauma, or vascular compromise. This article reviews key literature related to tendinopathies in the lower extremity and comments on the dearth of similar articles for the elbow and forearm. Hand therapists are encouraged to embrace this new terminology and to engage in research in this difficult area to improve treatment regimens and outcome measures.

Tendon injury and tendinopathy: healing and repair

Tendon disorders are frequent and are responsible for substantial morbidity both in sports and in the workplace. Tendinopathy, as opposed to tendinitis or tendinosis, is the best generic descriptive term for the clinical conditions in and around tendons arising from overuse. Tendinopathy is a difficult problem requiring lengthy management, and patients often respond poorly to treatment. Preexisting degeneration has been implicated as a risk factor for acute tendon rupture. Several physical modalities have been developed to treat tendinopathy. There is limited and mixed high-level evidence to support the, albeit common, clinical use of these modalities. Further research and scientific evaluation are required before biological solutions become realistic options.

Rotator cuff injuries and treatment

Rotator cuff problems are among the most commonly encountered disorders of the shoulder, and are commonly seen by primary care physicians. Their exact mechanism for susceptibility to injury remains unclear; however, with an understanding of the shoulder's anatomy and biomechanics, we are better able to treat the insults incurred on the cuff. Early recognition, proper treatment, and appropriate follow-up may expedite healing and prevent the occurrence of further injury or complications.

[Pain after anterior cruciate ligament reconstruction: detail and treatment]

OBJECTIVE

Several factors can influence the occurrence of pain after anterior cruciate ligament (ACL) ligamentoplasty, namely, factors linked to the selection of graft, the surgical technique and rehabilitation program. The aim of this research was to review the literature for different types of pain experienced after ACL reconstruction to illuminate better prevention and treatment.

METHOD

We reviewed reports by searching the PUBMED* research engine using the key words pain, complication, and anterior cruciate ligament.

RESULTS

We found an increasing incidence of anterior pain after use of the patellar tendon for ACL reconstruction. Some anterior pain can be mistakenly interpreted as donor site morbidity or patello-femoral problems, but it is in fact linked to graft impingement caused by bad placement of tunnels and/or proliferation of a fibrovascular nodule on the ACL graft ("cyclops syndrome"). Some posterior-external pain, sometimes associated, can occur under the same circumstances. Cartilage, ligament or meniscal lesions or saphenous nerve injuries can explain some occurrences of pain. Pain linked to loco-regional factors such as reflex sympathetic dystrophy appear to be rare with rehabilitation and surgery.

CONCLUSION

The treatment of pain after ACL reconstruction lies first in the establishment of an etiologic diagnosis. Prevention, by controlling tendon-muscular and joint stress during rehabilitation, is essential and requires sound knowledge of biomechanical data.

Le travail musculaire excentrique : intérêts dans la prise en charge thérapeutique du sportif

OBJECTIVES

To review the research on the effects and indications of eccentric muscular contraction in the athlete.

METHODS

We searched the Medline database using the key words eccentric and negative work for reports of eccentric muscular contraction published from 1993 to 2004.

RESULTS

The physiologic features of eccentric contraction remain unknown but significantly differ from concentric contraction. Eccentric contraction has a specific effect: during sports practice, it permits the muscular and tendinous complex to support strain and strengthens the muscular action of articular stabilization. But eccentric contraction produces injuries: delayed-onset muscle soreness, and muscle rupture and tendinous injuries such as luxation, rupture, and tendinitis.

CONCLUSION

Treatment and prevention must have controlled protocols. In therapy, eccentric contraction must be realized at progressive speeds and resistances. Prevention of tendinous injury necessitates quantifying eccentric activity during training.

Patellar tendinopathy

Patellar tendinopathy is a common and serious condition in athletes. Although there have been many advances in the understanding of the histopathology, imaging, and surgical outcomes in this condition in the past decade, successful management of athletes with patellar tendinopathy remains a major challenge for both the practitioner and patient. There is a definite need for further prospective studies into etiological factors and randomized controlled trials into treatment choices.

Eccentric muscle contractions: their contribution to injury, prevention, rehabilitation, and sport

Muscles operate eccentrically to either dissipate energy for decelerating the body or to store elastic recoil energy in preparation for a shortening (concentric) contraction. The muscle forces produced during this lengthening behavior can be extremely high, despite the requisite low energetic cost. Traditionally, these high-force eccentric contractions have been associated with a muscle damage response. This clinical commentary explores the ability of the muscle-tendon system to adapt to progressively increasing eccentric muscle forces and the resultant structural and functional outcomes. Damage to the muscle-tendon is not an obligatory response. Rather, the muscle can hypertrophy and a change in the spring characteristics of muscle can enhance power; the tendon also adapts so as to tolerate higher tensions. Both basic and clinical findings are discussed. Specifically, we explore the nature of the structural changes and how these adaptations may help prevent musculoskeletal injury, improve sport performance, and overcome musculoskeletal impairments.

Acute and Chronic Tendon Injuries: Factors Affecting the Healing Response and Treatment

Objective:

Tendons have biomechanical properties based on collaborative remodeling of all their cells through normal lysis and synthesis. This review assesses factors that affect the healing response and presents solutions for rehabilitating acute and chronic tendon injuries.

Data Sources:

MEDLINE (1970–2002) and SPORTDiscus (1970–2002). Key words searched weretendon, tendinitis, tendinosis, tendinopathy, rehabilitation, ultrasound, NSAIDs, exercise, mobilization, aging, immobilization,andhealing.

Data Synthesis:

The biomechanical roles tendons play change throughout one’s lifetime and are influenced by maturation and aging, injury and healing, immobilization, exercise, medications, and therapeutic modalities. Suggestions from animal, case, and clinical studies are varied but provide solutions in the treatment of acute and chronic tendon injuries.

Conclusions and Recommendations:

All factors that affect the tendon structure should be considered in a rehabilitation program. Therapeutic exercise, medications, or therapeutic modalities should never be used as a stand-alone therapy.

Overuse injuries of the extensor mechanism in athletes

This article reviews the functional anatomy, pathophysiology, and overall management of overuse injuries of the extensor mechanism in athletes.

Rehabilitation concepts and supportive devices for overuse injuries of the upper extremities

Rehabilitation of overuse injuries requires the health care professional to understand normal and common pathologic mechanics of the patient's sport or physical activity. Evaluation of the total mechanics of the body, not just the local area presenting with discomfort, is important. [figure: see text] The cause of the presenting injury can be a dysfunction at a distant site. Rest and supportive devices are helpful in allowing the athlete to return to a normal activity level. A progressive reconditioning program needs to address strength and flexibility issues and endurance and eccentric exercises.

Intrinsic risk factors for the development of patellar tendinitis in an athletic population. A two-year prospective study

Retrospective studies have suggested various factors that might cause a disposition to develop patellar tendinitis, but no prospective data exist to determine any relationships. The purpose of this study was to determine the intrinsic risk factors for the development of patellar tendinitis in an athletic population. Before the study, 138 male and female students of physical education were evaluated for anthropometric variables, leg alignment characteristics, and muscle tightness and strength parameters. During the 2-year study, 19 of the 138 students developed patellar tendinitis. In all cases the diagnosis was confirmed by the presence of a hypoechogenic nodular lesion in the proximal region of the patellar tendon. Univariate and stepwise discriminant function analyses were performed comparing the various measurements. These analyses revealed that the only significant determining factor was muscular flexibility, with the patellar tendinitis patients being less flexible in the quadriceps and hamstring muscles (P < 0.05). The results of this study demonstrate that lower flexibility of the quadriceps and hamstring muscles may contribute to the development of patellar tendinitis in an athletic population. Therefore, the prevention of this condition in athletes should be focused on screening for and treating poor quadriceps and hamstring muscle flexibility.