Achilles tendinitis and peritendinitis: etiology and treatment

One hundred nine runners were treated conservatively without immobilization for overuse injury to the Achilles tendon. Treatment strategies were directed toward rehabilitation of the gastrocnemius/soleus muscle-tendon unit, control of inflammation and pain, and control of biomechanical parameters. One fair, 12 good, and 73 excellent results were reported, with a mean recovery time of 5 weeks. Followup was incomplete in 23 cases. The three most prevalent etiological factors were overtraining (82 cases), functional overpronation (61 cases), and gastrocnemius/soleus insufficiency (41 cases). The authors speculate that runners are susceptible to Achilles tendinitis with peritendinitis due to microtrauma produced by the eccentric loading of fatigued muscle, excess pronation producing whipping action of the Achilles tendon, and/or vascular blanching of the Achilles tendon produced by conflicting internal and external rotatory forces imparted to the tibia by simultaneous pronation and knee extension. Virtually all cases of Achilles tendon injury appear to result from structural or dynamic disturbances in normal lower leg mechanics and require active treatment regimens which attempt to establish normal function to prevent recurrence.     

Intrinsic risk factors for the development of achilles tendon overuse injury: a prospective study

BACKGROUND: Although Achilles tendon overuse injuries occur commonly, our understanding of the pathologic changes and the factors that predispose athletes to them is limited. PURPOSE: To identify measurable intrinsic risk factors for Achilles tendon overuse injuries. STUDY DESIGN: Cohort study (prognosis); Level of evidence, 2. METHODS: Sixty-nine male officer cadets followed the same 6-week basic military training. Before this training, each subject was evaluated for anthropometrical characteristics, isokinetic ankle muscle strength, ankle joint range of motion, Achilles tendon stiffness, explosive strength, and leisure and sports activity. During military training, Achilles tendon overuse injuries were registered and diagnosed by the same medical doctor. To identify the intrinsic risk factors, a multivariate analysis with the use of stepwise logistic regression was performed. The sensitivity, specificity, and cutoff values of the risk factors were evaluated by receiver operating characteristic curve analysis. RESULTS: Ten of the 69 male recruits (14.5%) sustained an Achilles tendon overuse injury diagnosed on the basis of medical history and clinical examination. Analysis revealed that male recruits with lower plantar flexor strength and increased dorsiflexion excursion were at a greater risk of Achilles tendon overuse injury. The cutoff value of the plantar flexor strength at 85% sensitivity was 50.0 N.m, with a 4.5% specificity; the cutoff value of the dorsiflexion range of motion at 85% sensitivity was 9.0 degrees , with 24.2% specificity. CONCLUSIONS: The strength of the plantar flexors and amount of dorsiflexion excursion were identified as significant predictors of an Achilles tendon overuse injury. A plantar flexor strength lower than 50.0 N.m and dorsiflexion range of motion higher than 9.0 degrees were possible thresholds for developing an Achilles tendon overuse injury.     

Imaging of triathlon injuries

Injuries in triathletes are common and are mostly overuse injuries. Rotator cuff tendinitis is the most common complaint from swimming, but the incidence of tendinopathy and rotator cuff tears on magnetic resonance imaging is comparable in triathletes without and with shoulder pain. Cycling injuries are mainly to the knee, including patellar tendinosis, iliotibial band syndrome, and patellofemoral stress syndrome, and to the Achilles tendon and the cervical and lumbar spine. Running is associated with most injuries in triathletes, during both training and racing, causing the athlete to discontinue the triathlon. In addition to knee injuries from running, triathletes may also develop foot and ankle, lower leg, and hip injuries similar to single-sport distance runners. Some injuries in triathletes may be mainly symptomatic during one of the three sports but are exacerbated by one or both of the other disciplines.     

Is Achilles tendon blood flow related to foot pronation?

In the etiology of Achilles tendinopathy (AT), it is frequently suggested that excessive pronation causes a vascular constriction of the Achilles tendon, described as the “whipping phenomenon” (Clement et al., 1984). Although previous studies focused on the association between pronation and AT, it is striking that the underlying association between foot pronation and blood flow has not been studied yet. Therefore, the aim of this study was to investigate whether the amount of pronation during running influences the Achilles tendon blood flow. Twenty‐five experienced runners, aged 34.5±10.2 years, participated in this study. 2D‐lower limb kinematics during barefoot and shod running in both frontal and sagittal plane were assessed. Blood flow of the Achilles tendon was measured before and after barefoot and shod running, using the oxygen‐to‐see device. The results of this study showed a significant effect of eversion excursion on the increase in Achilles tendon blood flow after shod running. More specifically, the more the eversion excursion observed, the lower the increase in blood flow (P=.013). We therefore suggest, in individuals with increased inversion at touchdown and increased eversion around midstance during shod running, that antipronation measures could be useful in both preventing and managing Achilles tendinopathy.     

Impact of rest duration on Achilles tendon structure and function following isometric training

Intervention programs are often sought to strengthen the Achilles tendon (AT ) due to its high injury rate. Long rest periods between loading cycles have been found to increase collagen synthesis by tenocytes, suggesting rest duration may be important for tendon adaptation in vivo ; however, exercise programs comparing long and short rest duration have not been directly compared. Fourteen adults completed a 12‐week progressive training intervention; training sessions consisted of 5×10 isometric plantarflexion contractions each of 3‐s duration performed at 90% of MVC three times weekly. Each leg was randomly allocated to long (LRT , 10‐s rest) or short rest training (SRT , 3‐s rest). We hypothesized that the leg allocated to LRT would demonstrate superior AT collagen organization compared to the leg receiving SRT , which would be related to improved biomechanical function. AT collagen organization and morphology were measured using ultrasound tissue characterization. AT properties were assessed before and after the intervention using a combination of dynamometry, ultrasound imaging, EMG , and motion capture. Contrary to our hypothesis, collagen organization did not improve following either training protocol; conversely, an unexpected decrease in echotype I proportion was seen after SRT (P <.001) but not LRT (P =.58), indicating an apparent protective effect of rest on collagen organization during isometric training. In contrast, AT adaptation was not appreciably enhanced by increasing intercycle rest duration; both protocols were equally effective at inducing significant strength gains and AT mechanical and material adaptation (P ≤.001). Further research is necessary to identify optimal loading characteristics for injury prevention and rehabilitation.     

Lower limb biomechanical factors associated with Achilles tendinopathy in runners: a systematic review

Sport Sciences for Health - Variations in lower limb biomechanics can predispose to Achilles tendinopathy (AT). However, evidence on lower limb biomechanical factors associated with AT in runners...     

Range of motion,muscle torque and training habits in runners with and without Achilles tendon problems

Achilles tendon injuries are common in runners. The aim of the present study was to analyse the training programme, any Achilles tendon problems, muscle eightness and range of motion of the ankle joint, and concentric and eccentric musle torques of the calf muscles in middle-distance runners with and without Achilles tendon problems. Eighty-three middle-distance runners answered a questionnaire on their sports background, training habits and any injuries. Thirty-four percent had suffered from some type of problem relating to the Achilles tendon. Ten of the athletes who had suffered from Achilles tendon problems and ten who had never had any Achilles tendon trouble were randomly selected. These 20 runners underwent a clinical examination. The range of motion of the ankle joint was recorded objectively by a hydraulic and computerised isokinetic dynamometer by measuring resistance to passive motion. Concentric and eccentric muscle torques of the gastrocnemius-soleus complex were recorded. The runners with Achilles tendon problems had trained for significantly more years and covered significantly longer distances per weck than runners without Achilles tendon problems. There were no significant differences in other training methods or in best results over 800 m and 1500 m. Runners with Achilles tendon problems had a significantly lower range of motion of the ankle joint. They also had significantly lower eccentric torques of the gastroenemius-soleus complex, but no differences in concentric torques were found between the groups.     

Kinematic classification of iliotibial band syndrome in runners

Several inconsistent causative biomechanical factors are considered to be crucial in the occurrence of iliotibial band syndrome (ITBS). The focus of this study was on assessing differences in the kinematic characteristics between healthy runners [control group (CO)] and runners with ITBS in order to recommend treatment strategies to deal with this injury. Three‐dimensional kinematics of barefoot running was used in the biomechanical setup. Both groups were matched with respect to gender, height and weight. After determining drop outs, the final population comprised 36 subjects (26 male and 10 female): 18 CO and 18 ITBS (13 male and five female, each). Kinematic evaluations indicate less hip adduction and frontal range of motion at the hip joint in runners with ITBS. Furthermore, maximum hip flexion velocity and maximum knee flexion velocity were lower in runners with ITBS. Lack of joint coordination, expressed as earlier hip flexion and a tendency toward earlier knee flexion, was found to be another discriminating variable in subjects with ITBS compared with CO subjects. We assume that an increase in range of motion at the hip joint, stretching of the hip abductors, as well as stretching the hamstrings, calf muscles and hip flexors will help treat ITBS.     

Lower limb kinematics of subjects with chronic achilles tendon injury during running

This study examined the kinematic differences between subjects who had a history of chronic Achilles tendon (AT) injury and matched controls during running. Eleven subjects from each group ran barefoot (BF) and shod at self-selected speeds on a treadmill. Three-dimensional angles describing rearfoot and lower limb motion were calculated throughout stance. Five footfalls were obtained for each subject and condition. Pairwise comparisons revealed greater eversion, ankle dorsiflexion and less leg abduction during stance in the AT group compared with controls. Running kinematics were exaggerated in shod compared with BF conditions, as expected from previous research. The differences between conditions were more exaggerated in AT subjects compared with control subjects. Further analysis using a curve-based approach is recommended.     

Differences in kinematics of single leg squatting between anterior cruciate ligament-injured patients and healthy controls

Seventy to eighty percent of all anterior cruciate ligament (ACL) injuries are due to non-contact injury mechanisms. It has been reported that the majority of injuries due to single leg landing come from valgus positioning of the lower leg. Preventing valgus positioning during single leg landing is expected to help reduce the number of ACL injuries. We found that many ACL-deficient patients cannot perform stable single leg squatting. Therefore, we performed 3D motion analysis of the single-legged half squat for ACL-injured patients to evaluate its significance as a risk factor for ACL injuries. We evaluated the relative angles between the body, thigh, and lower leg using an electromagnetic device during single leg half squatting performed by 63 ACL-injured patients (32 males, 31 females) the day before ACL reconstruction and by 26 healthy control subjects with no knee problems. The uninjured leg of ACL-injured male subjects demonstrated significantly less external knee rotation than that of the dominant leg of the male control. The uninjured leg of ACL-injured female subjects demonstrated significantly more external hip rotation and knee flexion and less hip flexion than that of the dominant leg of the female control. Comparing injured and uninjured legs, the injured leg of male subjects demonstrated significantly less external knee and hip rotation, less knee flexion, and more knee varus than that of the uninjured leg of male subjects. The injured leg of female subjects demonstrated more knee varus than that of the uninjured leg of female subjects. Regarding gender differences, female subjects demonstrated significantly more external hip rotation and knee valgus than male subjects did in both the injured and uninjured legs (P < 0.05). The current kinematic study exhibited biomechanical characteristics of female ACL-injured subjects compared with that of control groups. Kinematic correction during single leg half squat would reduce ACL reinjury in female ACL-injured subjects.     

Plantar fasciitis in runners. Treatment and prevention

Plantar fasciitis is a common overuse injury found in runners. The plantar fascia, which is responsible for maintaining the integrity of the longitudinal arch, becomes irritated, inflamed or torn by repetitive stresses placed upon it. Commonly cited predisposers of plantar fasciitis are excessive pronation, a flat or cavus foot, tight Achilles tendon, type of training shoes worn, and errors in the training routine. Once the plantar fascia becomes irritated a myriad of conservative measures may be used, including everything from rest, ice and elevation to steroid injections and, if all else fails, surgery. In most cases conservative treatment of one kind or another will alleviate the symptoms of plantar fasciitis. However, it is essential to determine and correct the cause of the problem in order for the runner to resume normal activity levels. Controlling anatomical/biomechanical inefficiencies of the feet, stretching and strengthening exercises for the lower extremity, proper training shoes, and reasonable training routines will alleviate the symptoms of plantar fasciitis in a large percentage of sufferers. To prevent this injury, runners should be aware of the potential overuse injury and take precautionary measures, e.g. seek a biomechanical/anatomical evaluation from a qualified practitioner. The practitioner can then offer suggestions as to the specific steps the runner should follow to prevent the injury condition.     

Kinematic risk factors for lower limb tendinopathy in distance runners: A systematic review and meta-analysis

IntroductionAbnormal kinematics have been implicated as one of the major risk factors for lower limb tendinopathy (LLT).ObjectiveTo systematically review evidence for kinematic risk factors for LLT in runners.MethodsIndividual electronic searches in PubMed, EMBASE and Web of Science were conducted. Two reviewers screened studies to identify observational studies reporting kinematic risk factors in runners with LLT compared to healthy controls. The Down and Black appraisal scale was applied to assess quality. A meta-analysis was performed provided that at least two studies with similar methodology reported the same factor.ResultsTwenty-eight studies were included: Achilles tendinopathy (AT) (9), iliotibial band syndrome (ITBS) (17), plantar fasciopathy (PF) (2), patellar tendinopathy (PT) (1), posterior tibial tendon dysfunction (PTTD) (1). Eighteen studies were rated high-quality and ten medium-quality. The meta-analyses revealed strong evidence of higher peak knee internal rotation, moderate evidence of lower peak rearfoot eversion and knee flexion at heel strike and greater peak hip adduction in runners with ITBS. Very limited evidence revealed higher peak ankle eversion in runners with PF and PTTD or higher peak hip adduction in PT.SignificancePeak rearfoot eversion was the only factor reported in all included LLTs; it is a significant factor in ITBS, PT and PTTD but not in AT and PF. More prospective studies are needed to accurately evaluate the role of kinematic risk factors as a cause of LLT. Taken together, addressing rearfoot kinematic and kinematic chain movements accompanied by peak eversion should be considered in the prevention and management of LLT.     

Achilles tendon adaptation during strength training in young adults

PURPOSE: Tendons are specialized musculoskeletal structures responsible for transferring forces between muscles and bones. To maintain joint mechanics and structural integrity, tendons must adapt to changes in mechanical loading, but little is known about the interaction between muscle and tendon adaptations in vivo. We tested the hypothesis that tendons adapt to changes in muscle strength to maintain strains within a preferred operating range. METHODS: The right lower leg of 10 male subjects, age 24.9 +/- 3.4 yr (mean +/- SD), mass 78.1 +/- 9.7 kg, and height 176.5 +/- 7.2 cm, were tested before and during weeks 1, 2, 4, 6, and 8 of an 8-wk ankle plantar flexion strength training program. Subjects performed isometric plantar flexion efforts slowly ramping up from rest to a maximum effort. Plantar flexion force, Achilles tendon deformation, and cross-sectional area were measured. Triceps surae muscle force (assumed equal to Achilles tendon force), normalized force, and Achilles tendon stress and strain were calculated. Achilles tendon strains during maximum plantar flexion efforts (epsilon(max)) were compared between weeks to test the hypothesis. Repeated-measures ANOVA was used to test for significant changes during the 8 wk, with alpha = 0.05 used as the criterion for significance. RESULTS: There were no significant differences in the group's mean percent or absolute change in epsilon(max) (P = 0.607 and 0.351, respectively) despite a 21.4% average increase in muscle strength during the 8 wk. CONCLUSIONS: This is the first study that quantifies Achilles tendon strain throughout a strength training program. Findings indicate that the Achilles tendon adapts quickly to muscle strength training and experiences relatively little change in peak strain despite large increases in muscle strength.     

Increased unilateral tendon stiffness and its effect on gait 2–6 years after Achilles tendon rupture

Achilles tendon rupture (ATR) alters tissue composition, which may affect long‐term tendon mechanics and ankle function during movement. However, a relationship between Achilles tendon (AT) properties and ankle joint function during gait remains unclear. The primary hypotheses were that (a) post‐ATR tendon stiffness and length differ from the noninjured contralateral side and that (b) intra‐patient asymmetries in AT properties correlate to ankle function asymmetries during gait, determined by ankle angles and moments. Ultrasonography and dynamometry were used to assess AT tendon stiffness, strain, elongation, and rest length in both limbs of 20 ATR patients 2–6 years after repair. Three‐dimensional ankle angles and moments were determined using gait analysis. Injured tendons exhibited increased stiffness, rest length, and altered kinematics, with higher dorsiflexion and eversion, and lower plantarflexion and inversion. Intra‐patient tendon stiffness and tendon length ratios were negatively correlated to intra‐patient ratios of the maximum plantarflexion moment and maximum dorsiflexion angle, respectively. These results suggest that after surgical ATR repair, higher AT stiffness, but not a longer AT, may contribute to deficits in plantarflexion moment generation. These data further support the claim that post‐ATR tendon regeneration results in the production of a tissue that is functionally different than noninjured tendon.     

Etiologic factors associated with Achilles tendinitis in runners.

PURPOSE: The purpose of this study was to determine whether relationships exist between selected training, anthropometric, isokinetic muscular strength, and endurance, ground reaction force, and rearfoot movement variables in runners afflicted with Achilles tendinitis. METHODS: Specifically, we examined differences in selected measures between a noninjured cohort of runners (N = 58) and a cohort of injured runners with Achilles tendinitis (N = 31). Isokinetic, kinetic, and kinematic measures were collected using a Cybex II+ isokinetic dynamometer (Medway, MA), AMTI force plate (500 Hz), and Motion Analysis high-speed videography (200 Hz), respectively. Separate discriminant function analyses were performed on each of the five sets of variables to identify the factors that best discriminate between the injured and control groups. RESULTS: Years running, training pace, stretching habits (injured runners were less likely to incorporate stretching into their training routine), touchdown angle, plantar flexion peak torque at 180 degrees x s(-1) and arch index were found to be significant discriminators. CONCLUSION: A combined discriminant analysis using the above mentioned significant variables revealed that plantar flexion peak torque, touchdown angle, and years running were the strongest discriminators between runners afflicted with Achilles tendinitis and runners who had no history of overuse injury.     

The prevalence of Achilles and patellar tendon injuries in Australian football players beyond a time‐loss definition

Little is known about the prevalence and associated of morbidity of tendon problems. With only severe cases of tendon problems missing games, players that have their training and performance impacted are not captured by traditional injury surveillance. The aim of this study was to report the prevalence of Achilles and patellar tendon problems in elite male Australian football players using the Oslo Sports Trauma Research Centre (OSTRC ) overuse questionnaire, compared to a time‐loss definition. Male athletes from 12 professional Australian football teams were invited to complete a monthly questionnaire over a 9‐month period in the 2016 pre‐ and competitive season. The OSTRC overuse injury questionnaire was used to measure the prevalence and severity of Achilles and patellar tendon symptoms and was compared to traditional match‐loss statistics. A total of 441 participants were included. Of all participants, 21.5% (95% CI : 17.9‐25.6) and 25.2% (95% CI 21.3‐29.4) reported Achilles or patellar tendon problems during the season, respectively. Based on the traditional match‐loss definition, a combined 4.1% of participants missed games due to either Achilles or patellar tendon injury. A greater average monthly prevalence was observed during the pre‐season compared to the competitive season. Achilles and patellar tendon problems are prevalent in elite male Australian football players. These injuries are not adequately captured using a traditional match‐loss definition. Prevention of these injuries may be best targeted during the off‐ and pre‐season due to higher prevalence of symptoms during the pre‐season compared to during the competitive season.     

Asymmetry of Achilles tendon mechanical and morphological properties between both legs

Although symmetry of Achilles tendon (AT) properties between legs is commonly assumed in research and clinical settings, different loading profiles of both legs in daily life (i.e., foot dominance) may affect the tendon properties in a side‐depended manner. Therefore, AT properties were examined with regard to symmetry between legs. Thirty‐six male healthy adults (28 ± 4 years), who were physically active but not involved in sports featuring dissimilar leg load participated. Mechanical and morphological AT properties of the non‐dominant and dominant leg were measured by means of ultrasound, magnetic resonance imaging and dynamometry. The AT of the dominant leg featured a significant higher Young's modulus and length (P < 0.05) but a tendency toward lower maximum strain (P = 0.068) compared with the non‐dominant leg. The tendon cross‐sectional area and stiffness were not significantly different between sides. The absolute asymmetry index of the investigated parameters ranged from 3% to 31% indicating poor AT side symmetry. These findings provide evidence of distinct differences of AT properties between both legs in a population without any sport‐specific side‐depended leg loading. The observed asymmetry may be a result of different loading profiles of both legs during daily activities (i.e., foot dominance) and challenges the general assumption of symmetrical AT properties between legs.     

The association between eccentric hip abduction strength and hip and knee angular movements in recreational male runners: An explorative study

Weak hip abductors may be related with increased hip adduction and knee abduction angular movement, which may be risk factors of lower extremity injuries. As the role of eccentric hip abduction strength (EHAS ) on hip adduction angular movement and knee abduction angular movement (KABD ) remains unclear, the purpose of this study was to explore the association between EHAS and hip and knee angular movement. In 100 healthy male recreational runners, EHAS was quantified using an isokinetic dynamometer, while hip and knee angular movements were collected using pressure‐sensitive treadmill and Codamotion active marker system. Using multiple linear regression models (n=186 legs), no relationships between EHAS and hip and knee kinematics were found. A possible reason for the lack of relationship between EHAS and hip and knee kinematics may be owing to differences in the running kinematics. Some runners with weak EHAS may compensate the weakness by leaning toward the stance limb and thereby reduces the demand on the hip abductors with the consequence of increased knee abduction moment, which may lead to an increased knee abduction angular excursion. Possible, others mechanism as the quadriceps strength and activity in the hip and thigh muscles may also be able to explain the lack of relationship that may or may not exist. Despite the inconclusive results of this study, the findings may suggest that weak hip abductor muscles may be a relevant factor to focus on in future studies.     

High-arched runners exhibit increased leg stiffness compared to low-arched runners

Leg stiffness between high-arched (HA) and low-arched (LA) runners was compared. It was hypothesized that high-arched runners would exhibit increased leg stiffness, increased sagittal plane support moment, greater vertical loading rates, decreased knee flexion excursion and increased activation of the knee extensor musculature. Twenty high-arched and 20 low-arched subjects were included in this study. Leg stiffness, knee stiffness, vertical loading rate and lower extremity support moment were compared between groups. Electromyographic data were collected in an attempt to explain differences in leg stiffness between groups. High-arched subjects were found to have increased leg stiffness and vertical loading rate compared to low-arched runners. Support moment at the impact peak of the vertical ground reaction force was related to leg stiffness across all subjects. High-arched subjects demonstrated decreased knee flexion excursion during stance. Finally, high-arched subjects exhibited a significantly earlier onset of the vastus lateralis (VL) than the low-arched runners. Differences exist in leg stiffness and vertical loading rate between runners with different foot types. Differences in lower extremity kinetics in individuals with different foot types may have implications for new treatment strategies or preventative measures.