NASMI and Advances in Clinical Education

Good thoughts from Mike Reinold…

One of the most common postoperative complications following ACL reconstruction is loss of range of motion, particularly loss of knee extension. Recent studies have shown that up to 25% of all ACL reconstructions will have a loss of knee extension range of motion postoperatively. That seems like a pretty significant amount of people to me.

Biomechanically, loss of knee extension range of motion has some fairly serious implications. In addition to increased patellofemoral issues and potential wear and tear to the articular cartilage, loss of knee extension creates an environment that does not allow the knee to lock into the “screw home” mechanism. In turn, you can’t lock out your knee and your quadriceps has to fire at all times to stabilize the knee. Over time, these patients tend to struggle with quadriceps strength gains and return to functional activities.

All this considered, as rehabilitation specialists, one of our prime concerns when working with ACL reconstructions patients has to be restoring full passive knee extension as soon as possible. People familiar with accerlerated protocols will know that this is emphasized immediately after surgery.

Understanding risk factors that are associated with loss of motion following ACL reconstruction will allow us to identify specific patients that are at great risk.

It has been documented that preoperative range of motion is highly correlated with postoperative range of motion, meaning that the more motion you have going into surgery, the more you’ll have after surgery. This has led to a trend of delaying surgery to allow the knee to “quite down,” so to say, and allow for the reduction of effusion and inflammation.

A new study set to be published in an upcoming issue of the American Journal of Sports Medicine has also identified that the presence of a bone bruise also correlates with loss of motion. In this study, 75% of patients with preoperative loss of motion and 46% of patients with a bone bruise on the lateral femoral condyle and lateral tibial plateau presented with delayed range of motion recovery. Considering that past studies have shown bone bruises to be present in 70-80% of ACL injuries, this is a significant finding. Read the rest of this entry »

For those of you who have never been to one of our courses not only do you get quality physical therapy continuing education but you also get to hang out with this guy!! A very special thanks to our great hosts in Abilene, TX, especially the one who captured this moment out on the dance floor. After a hard days work we like to let loose…check it out.

BG Gets Down in TEXAS

From Sports Medicine Research: In the Lab & In the Field

Written by: Mark Rice

Reviewed by: Stephen Thomas

Risk factors of recurrent hamstring injuries: a systematic review

de Visser H, Reijman M, Heijboer M, Bos P. Br J Sports Med. 2011 Oct 19. [Epub ahead of print] (Link to abstract)

We have all been there, in the heat of competition, or deep into a practice, one of our athletes goes down with a hamstring strain. We immediately begin managing inflammation and pain, but how often do we sit back and ask ourselves “is there something that predisposed this athlete to injury?” In this article De Visser et al. attempted to answer that question. While there is no shortage of articles available detailing hamstring injuries, injury classification, and treatment; there is currently very little data available on hamstring re-injury risk factors. By performing a systematic review of available literature, the authors were able to identify 131 prospective articles on hamstring re-injury risk factors post acute injury. Of the studies identified, only 5 studies possessed the adequate inclusion criteria: 1) subjects diagnosed with a Grade 1-3 acute hamstring strain on physical exam or Grade 0-3 when identified through MRI or sonography in conjunction with physical exam (using the Peetrons study criteria) 2) Prospective study with 2 week minimum follow-up after return to sport 3) Full-text available. The data from these studies show that the hamstring re-injury incidence rate is anywhere from 13.9-63.3% during the same season and up to 2 years after the initial injury. Due to the low number of studies identified (n = 5), the authors were able to discover limited evidence for 3 potential re-injury risk factors. First, 2 articles identified that athletes which initially sustained a Grade 1 hamstring strain were more likely to re-injure the affected hamstring (24.1-35%) than other individuals who sustained a Grade 0 (0-9.3%) or Grade 2 (6.3%) initial injury. Another identified risk-factor for hamstring re-injury was an ipsilateral ACL reconstruction. When compared to athletes that haven’t undergone ACL reconstruction, the re-injury incidence rate is 66.6% vs 17.1%, irrespective of graft type. One final item identified as a risk factor for re-injury was a larger tear area upon initial injury as identified by MRI, 47.03 vs 12.42 cm³. Finally, one other item that was identified for a lower risk of re-injury was the rehabilitation program format. Programs focusing on ‘agility and stabilization’ were more successful at limiting re-injury than ‘stretching and strengthening’ programs, 7.7% vs 70% respectively.

This article is of interest for a several reasons. Not only does it identify items that seem to be fairly elementary risk factors for hamstring re-injury, but the inclusion of ACL reconstruction presents an intriguing pathway for further discussion. Is there some level of neuromuscular compromise as far as the hamstrings are concerned post-ACL reconstruction and is this an area to begin focusing on even further in order to not only protect the reconstructed knee, but also to limit any re-injury to the hamstrings? While this study has very limited data to draw upon, it does shine some light on areas that we need to take into consideration at the onset of an initial hamstring strain as well as post-ACL reconstruction. This study also illustrates that perhaps the hamstring responds better to agility like exercises as opposed to strengthening. That isn’t to say that strengthening should be forsaken, but as the athlete recovers and gets closer to returning to play, perhaps the balance between strength exercises and agility exercises may need to shift more towards the latter. Another item that might need to be taken into consideration is some form of diagnostic imaging to be able to truly determine the severity of a hamstring injury. While an MRI might be cost prohibitive, the use of ultrasound might be an attractive option to help us visualize the injury, for structuring our or rehabilitation protocols as well as giving us an idea what the likelihood of re-injury realistically might be for the individual. What are your thoughts on this study? Do any of the risk-factors surprise you? What sort of efforts do you make after your athlete sustains their first hamstring injury to prevent subsequent injury?

From Sports Medicine Research: In the Lab & In the Field

Written by: Nicole Cattano

Reviewed by: Jeffrey Driban

Prospective evaluation of patients with anterior cruciate ligament reconstruction using a patient-based health-related survey: comparison of single-bundle and anatomical double-bundle techniques

Ochial S, Hagino T, Segna S, Saito M, & Haro H. Archives of Orthopaedic Trauma Surgery. 2011 December 9. [Epub ahead of print] doi: 10.1007/s00402-011-1443-x (Link to abstract)

Anterior cruciate ligament (ACL) reconstruction is commonly performed on the athletic population to restore function and return to pre-injury sporting activities. There is much debate on the optimal surgical technique to restore kinematics and subjective findings. The purpose of this prospective randomized study was to compare the subjective and objective outcomes of the single-bundle and anatomical double-bundle ACL reconstruction techniques. A total of 84 males were included in the study and evaluated pre-reconstruction, and at 6-months, 12-months, and 24-months post ACL reconstruction. Patients were evaluated objectively for knee stability (i.e., pivot shift and anterior tibial translation using a Telos SE stress device) and subjectively for function (i.e., Lysholm and Short Form-36 questionnaires). There were significant improvements in subjective and objective outcomes between pre- and post-ACL reconstruction, however there were no significant differences found between ACL reconstruction groups at any of the time points.

Patients oftentimes ask clinicians what surgical technique they would choose for ACL reconstruction. It would appear that, between these two surgical approaches, there is no superior answer. There was a high level of patient satisfaction in both groups. The authors limited the inclusion criteria to males only due to the difficulties of performing the double-bundle technique on females who have smaller intercondylar notches. It is interesting that the double-bundle technique was performed on a group unlikely to have any complications and it still failed to show superiority. It would appear that the single-bundle reconstruction technique provides the same outcomes as the double-bundle reconstruction technique, without the added risk of complications. The authors noted that their placement of the single-bundle graft was similar to anatomic placement of the original ACL compared to traditional single-bundle techniques. Furthermore, an anatomic single-bundle reconstruction has been demonstrated to improve rotational instability better than traditional surgical approaches. However, in the current study the authors did not compare their graft placement in the single-bundle technique to the original single-bundle graft placement. Rather than replicating the two bundles of the ACL through a more complicated surgery, it may be that research needs to focus on improving anatomical placement of the new graft. Beyond surgical techniques we may also need to pay more attention to the rehabilitation processes and return-to-play criteria. The idea of treating the “whole patient” and not just the patient’s knee seems to be gaining support. I fear that surgical techniques have gotten so advanced that return to play is borderline rushed and that while the patient may be physically healed, they may not be ready to return to play. In making return to play decisions it may be beneficial to not just look at strength, function, and physical healing, but also possibly looking at criteria such as neuromuscular patterns and mental status (e.g., confidence, fear, anxiety). Does anyone have any experience evaluating these criteria or thoughts on these examples or other criteria that should be evaluated?

From Sports Medicine Research: In the Lab & In the Field

Written by: Lisa Chinn

Reviewed by: Jeffrey Driban

Preventive effect of eccentric training on acute hamstring injuries in men’s soccer: A cluster-randomized controlled trial

Petersen J, Thorborg K, Bachmann Nielsen M, Budtz-Jorgensen E, Holmich P (2011). Am J Sports Med, 39 (11), 2296-2303. (Link to abstract)

Hamstring muscle strains are very common in sports, especially soccer. The majority of injuries seem to occur when the hamstrings are contracting eccentrically, indicating a need for research on the efficacy of eccentric exercises on the prevention of hamstring injuries. This study used a cluster-randomized controlled trial to evaluate whether a 10-week training program using the Nordic hamstring exercise could lower the incidence of new and recurrent hamstring injuries. 54 male Dutch soccer teams were randomly assigned to either the 10-week intervention group (23 teams, 461 players) or a control (27 teams, 482 players) condition. The intervention was the Nordic hamstring exercise, a partner exercise in which one participant is supporting the ankles/lower legs of a second partner who is kneeling. The kneeling partner attempts a forward-falling motion (keeping hips/body rigid and in-line with legs) using his hamstring muscles to resist the fall. During team training sessions, coaches were asked to perform the exercise up to 3 times a week for a minimum of 10 weeks during a mid-season, non-competitive break (27 sessions). Hamstring injury (new and recurrent) and severity (days missed) were recorded for a year following the intervention. The control group reported 52 hamstring injuries (32 new and 20 recurrent) whereas the intervention group had a total of 15 injuries (12 new and 3 recurrent). Comparing the two groups, the Nordic hamstring intervention group significantly reduced total hamstring injury rates, as well as new and recurrent injuries. A numbers needed to treat analysis found that to prevent one hamstring injury (new or recurrent) 13 players need to perform the intervention. The intervention did not influence injury severity.

This study was the first to report the reduction of hamstring injury using the Nordic hamstring exercise in a cluster-randomized controlled trial study design. This simple, partner implemented eccentric exercise was found to reduce total hamstring injury rate by more than 60% and recurrent rate by approximately 85%. Overall, this study evaluated how integrating a quick eccentric exercise can help athletes who have sustained a hamstring injury reduce the risk of recurrent injury. As sports medicine professionals, we know the importance of including strengthening exercises into our rehabilitation programs for injured athletes. However, often times we feel we need the newest high-tech, expensive equipment and gadgets to accomplish our goals. This study clearly shows that, in the case of hamstring rehabilitation, this may not be true. Although this study did not evaluate the affect of the Nordic hamstring exercise in rehabilitation protocols specifically, it does show potential for the incorporation of this simple exercise into rehab. The Nordic hamstring exercise only requires a partner for support and can be performed almost anywhere (clinic, field, turf, etc). Not only can this exercise be done to prevent recurrent injury, sports medicine personnel can encourage coaches to implement this into their regular training programs because of the ease of implementation and short amount of time needed to complete the exercise. One of the weaknesses of this study is that it only included male soccer players. What are your thoughts on other sports performing this exercise, will it be as affective? Also, what about in females? As sports medicine professionals, is this an exercise you have incorporated into your hamstring rehabilitations? If no, would you consider it? If yes, do you feel it is as successful as this study’s results?

From Sports Medicine Research: In the Lab & In the Field

Written by: Mark Rice

Reviewed by: Stephen Thomas

Rotator-cuff muscle-recruitment strategies during shoulder rehabilitation exercises.

Swanik KA, Huxel Bliven K, Swanik CB. J Sport Rehabil. 2011 Nov;20(4):471-86. (Link to abstract)

Do you remember diving into your first upper extremity therapeutic exercise class? Looking back, it seems like from day one that we were taught to hammer the rotator cuff for any and all shoulder injuries. While we were wrestling to understand the dynamic stabilization aspect, one thing that wasn’t so readily taught or considered when constructing a rehabilitation protocol is what the magnitude of muscle activation might be for these muscles throughout the entire motion arc of a selected exercise. Is it possible that we should be even more judicious about which exercises are selected, and when they are placed within a rehab protocol? In this study Swanik et al. investigated muscle coactivation levels and coactivation patterns of the subscapularis, infraspinatus, and teres minor throughout the range of motion (ROM) of 4 commonly utilized therapeutic exercises. These muscles make up the force couple which opposes anterior-posterior glenohumeral joint translation. Muscle activity of the supraspinatus was also recorded. For this study, 33 healthy, physically active men (~20 years old) were recruited. The dominant arm was tested on each and was defined as the extremity that they would use to throw a ball (right, n = 26; left, n = 7). All subjects then completed bouts of D2 PNF pattern with resistive tubing, kneeling 90/90 pitchback with a 1.1 kg plyoball, a push up plus, and horizontal ab/adduction on a slide board while on their hands and knees. Cotton coverings were placed over the subjects hands to decrease friction throughout the exercise’s ROM. The selected muscles of each subject were connected to fine wire intramuscular electrodes to obtain the muscular activation data. Data obtained showed that muscle co-activation levels ranged anywhere from 47 to 60% for the selected exercises with no significant differences between the exercises. The authors did find significant differences in coactivation patterns, with the most noticeable instances occurring at the initiation of the exercise (first 0 to 20% of exercise completion) and when the glenohumeral joint was in a vulnerable position at end range ROM (flexion, abduction, and/or external rotation). Furthermore, the subscapularis was the only muscle to exhibit significant increases in muscle activation when examining its individual activation for each exercise. The two exercises showing the most subscapularis recruitment were the push-up plus and the slide board exercise. The push-up plus was the only exercise for the subscapularis that demonstrated a significant increase in muscle recruitment. The slide board exercise exhibited the second most supraspinatus activation, but this did not reach statistical significance.

This article is interesting for a few reasons. First and foremost, it is truly one of the first articles to determine what is going on at the muscular level throughout an exercise’s entire ROM. While it does have some short-comings (e.g., including healthy males only), the results allow us to quantitatively see what is occurring. As clinicians we can use this information to better structure our rehab protocols by initiating the proper exercises at the proper time during the patients recovery and progression. Knowing which exercises your patient will get the best results from and where in the motion they will get the most out of those exercises during their utilization is invaluable. Future studies will potentially need to focus on other exercises so that clinicians can have a broader knowledge base in terms of muscular activity over the entire ROM. What are your thoughts on this study? Would you like to have seen them incorporate any injured subjects? If you are utilizing closed chain exercises in shoulder protocols, are you inclined to use them even more, based upon these results? If you aren’t using closed chain exercises, will you consider using them now?

From Sports Medicine Research: In the Lab & In the Field

Written by: Nicole Cattano

Reviewed by: Jeffrey Driban

Does anterior cruciate ligament reconstruction lead to degenerative disease? Thirteen-year results after bone-patellar tendon-bone autograft

Murray JRD, Lindh AM, Hogan NA, Trezies AJ, Hutchinson JW, Parish E, Read JW, & Cross MV. American Journal of Sports Medicine. 2011 November 23. [Epub ahead of print] doi: 10.1177/0363546511428580 (Link to abstract)

Anterior cruciate ligament (ACL) rupture is common in the athletic population. Many studies have demonstrated favorable short-term patient-centered outcomes after an ACL reconstruction; however, the long-term consequences of ACL reconstructions remain unclear. The purpose of this study was to identify the incidence of osteoarthritis (OA) in patients that have undergone ACL reconstruction utilizing the bone-patellar tendon-bone autograft technique as well as to identify factors associated with poor radiographic and patient-centered outcomes. A total of 114 patients were included in the study and followed up with, on average, 13-years post ACL reconstruction. Patients were evaluated for knee stability (i.e., Lachman, pivot shift, KT-1000), function (i.e., range of motion, Lysholm, International Knee Documentation Committee [IKDC] questionnaire), and joint structural status (i.e., radiographs). Most patients had relatively high patient satisfaction (average 9 out of 10), good knee stability (~83% KT-1000 contralateral difference ? 3 mm), returned to sporting activity at their previous level (55%) and low re-rupture (4%) rates. In this cohort, 33% of the patients (28 out of 84 knees) evaluated had poor radiographic outcomes (OA) compared to 24% of assessed contralateral uninjured knees (10 out of 42 knees). Factors that were associated with poor radiologic outcome in the ACL reconstructed knee were injury to the cartilage or meniscus, meniscectomy performed with ACL reconstruction, a poor IKDC subjective score, and the radiographic status of the contralateral medial compartment. Similar factors, including chondral injury, previous surgery, previous surgery, not returning to sport, and poor radiographic grades, were identified as being associated with poor subjective outcomes (i.e., IKDC and Lysholm).

This study demonstrates that a considerable number of knees with a history of an ACL reconstruction have a high incidence of knee OA. This study also provides important information about which factors may predispose patients to poor outcomes (radiographic and patient-reported). This is the second study that I have recently reviewed that has shown no association between stability and patient-reported outcomes. This further emphasizes that patient-reported outcomes may not be entirely linked to restoration of biomechanics. Concomitant injuries to the meniscus or cartilage appear to increase the likelihood of radiographic OA and poor patient-reported outcomes. It is very interesting that for the subgroup analyses, the only significant difference found was that all cartilage injuries were found in the delayed surgical group. The authors attribute all cartilage injuries being found in the delayed surgical group to the prolonged altered biomechanics while waiting to undergo surgery > 2 months post injury. It may be critical to monitor patients for concurrent chondral or meniscal injuries as well as other structural changes and if present a plan may be needed to repair the secondary pathology rather than taking a wait and see approach. Has anyone had any experiences with athletes’ early development of cartilage defects? What factors or previous injuries have you clinically seen associated with the development of cartilage injury? It would be interesting to see the incidence of chondral defects over time after an ACL injury or isolated meniscus tears.

From Sports Medicine Research: In the Lab & In the Field

Blog Written by: Meghan Miller

Reviewed by: Jeffrey Driban

Radiographic Prevalence of Femoroacetabular Impingement in Collegiate Football Players: AAOS Exhibit Selection

Kapron AL, Anderson AE, Aoki SK, Phillips LG, Petron DJ, Toth R, Peters CL. J Bone Joint Surg AM 2011;93:e111(1-10) (Link to abstract)

In recent years, an increase in diagnosis of femoroacetabular impingement syndrome (FAI) has been seen in athletes. It has been suggested that increased stress applied to developing bones of adolescent athletes may initiate bone remodeling and osteophyte (bone spur) formation, causing abnormalities associated with FAI. These abnormalities, when paired with repeated joint stress, may increase the occurrence of hip pain and labral tears seen in athletes (e.g., football players). The purpose of this study was to use radiographic imaging to quantify the prevalence of FAI in asymptomatic football players. Sixty-seven Division IA football players agreed to participate; each hip was examined separately. Each player filled out a questionnaire based upon the Hip Outcome Score survey on the same day that their hip radiographs were performed. Nearly every subject reported a score of 90% or better; indicating that all but one of the football players were asymptomatic. Anteroposterior and frog-leg views were used for anterior and lateral inspection, respectively. Two orthopaedic surgeons independently evaluated the images and assessed five anatomical measurements that characterize the shape of the femoral head and neck. Cut-off values were specified for each of the 5 measures; each hip either exhibited a sign of FAI or didn’t (see the article for additional information regarding the two forms of FAI). At least one sign of FAI was seen in 95% of hips. When an anatomic abnormality associated with FAI was detected in a player it occurred bilaterally in more than 48% of players (three of the abnormalities, when present, occurred bilaterally in more than 80% of the players with the abnormality).

These results suggest that collegiate football players presenting with hip pain should be evaluated for bony abnormalities to determine if FAI is the underlying cause. As the body mass of football players is different than that of other sports, it would be interesting to see this study conducted in a different population of high-level athletes. Studying the prevalence of FAI in other athletic populations may help explain the role of body mass, repetitive loading, and age at the onset of competitive sport participation. One thing uncontrolled for was the position of the pelvis. As pelvic tilt may affect bony alignment, it would be of interest to compare the prevalence results of this study to one in which pelvic positioning was controlled for. Have you seen an increase in the number of FAI cases you treat? What other sports seem to have a high prevalence of FAI cases?

From Sports Medicine Research: In the Lab & In the Field

National Athletic Trainers’ Association Position Statement: Preventing Sudden Death in Sports

Casa DJ, Guskiewicz KM, Anderson SA, Courson RW, Heck JF, Jimenez CC, McDermott BP, Miller MG, Stearns RL, Swartz EE, Walsh. Journal of Athletic Training. 2012;47(1):1-24. (Link to position statement)

The National Athletic Trainers’s Association has released a position statement intended to provide recommendations “for the prevention and screening, recognition, and treatment of the most common conditions resulting in sudden death in organized sports.” The overall goal of this document “is to guide the development of policies and procedures that can minimize the occurrence of catastrophic incidents in athletes.”

The position statement covers 10 conditions: 1. asthma 2. catastrophic brain injuries 3. cervical spine injuries 4. diabetes 5. exertional heat stroke 6. exertional hyponatremia 7. exertional sickling 8. head-down contact in football 9. lightening 10. sudden cardiac arrest

From Sports Medicine Research: In the Lab & In the Field

Blog Written by: Kyle Harris

Reviewed by: Jeffrey Driban

Hip Kinematics During a Stop-Jump Task in Patients with Chronic Ankle Instability

Brown CN, Guskiewicz KM, Marhsall SW, Padua DA. J of Athl Training. 2011 September; 46(5): 461-471. (Link to abstract)

Lateral ankle sprains are common injuries sustained by both recreational and competitive athletes. After sustaining a lateral ankle sprain, individuals are at an increased risk of developing chronic ankle instability (CAI; subjective repeated episodes of giving away). Both mechanical ankle instability (MAI; ligament laxity) and functional ankle instability (FAI; proprioceptive deficits) are potential factors in the development of CAI. The authors report that there are a number of conflicting reports regarding kinematics differences in patients with and without CAI (“copers” = those with a history of a moderate to severe ankle sprain but no self-reported episodes of giving way in the past year). Therefore, Brown and colleagues completed a cross-sectional study to determine whether people with MAI or FAI exhibited different hip biomechanics during a stop-jump task compared with “copers”. A total of 63 recreational athletes (1.5 hrs/week) were divided into 3 groups (MAI, FAI, copers; 11 males, 10 females per group). Subjects reported a history of acute ankle sprains within the past 5 years. All subjects were evaluated through an orthopedic examination (performed by an experienced athletic trainer) and completed self-reported questionnaires (demographic, ankle injury history, Foot and Ankle Disability Index, and Foot and Ankle Disability Index Sport Subscale). All volunteers then performed a jump-stop task “similar to motions used in basketball and soccer.” Kinematics were measured using an electromagnetic tracking device and piezoelectric nonconductive force plate. Each subject was allowed to practice the maneuver 3 times, followed by 8 successful trials with 30 seconds of rest between each trial. For each trial, the subject “took a 3- or 4-step approach run at 2.5 to 3.5 m/s, took off on 1 foot, landed with both feet at the same time (test foot on the force plate and the other foot off the force plate), and then performed a maximal vertical jump and landed in approximately the same position.” Measured variables included hip flexion, abduction, and rotation at initial contact, at maximum ground reaction force, and displacement (total range of motion from minimum to maximum joint angle). Results revealed that the MAI group displayed greater hip flexion displacement than both “copers” and the FAI group. Although, these variations between groups were observed no differences existed with respect to hip abduction variable or any ground reaction force variables.

This study presents an interesting look at a need for clinicians to assess landing strategies in patients with CAI to ensure no compensations are occurring. The authors also call on clinicians to address issues of hip range of motion and strength during ankle rehabilitation. The results of this study serve as a good reminder that after injury, changes in the kinetic chain may exist.. If these kinematic changes in landing remain, it is reasonable to think that this could increase the risk of the athlete experiencing another injury in the kinetic chain, as we understand that landing kinematics are crucial to the proper absorption of shock through the kinetic chain. Have you seen athletes with CAI sustain other injuries after returning to play? Do you perform whole kinetic chain evaluations of your athletes in conjunction with ankle rehabilitation?