Brian G. Pietrosimone

Neuromuscular consequences of anterior cruciate ligament injury.

The neuromuscular consequences of anterior cruciate ligament (ACL) injury are important considerations because these deficits play a crucial role in a patients recovery following ACL injury or reconstruction. The purpose of this article is to review and synthesize the known neuromuscular consequences of ACL injury and reconstruction. Specifically, changes in somatosensation, muscle activation, muscle strength, atrophy, balance, biomechanics, and patient-oriented outcomes are discussed. Understanding neuromuscular consequences aids in the construction of optimized rehabilitation strategies.

Immediate Effects of Transcutaneous Electrical Nerve Stimulation and Focal Knee Joint Cooling on Quadriceps Activation

PURPOSE To determine whether transcutaneous electrical nerve stimulation (TENS) and focal knee joint cooling will affect the quadriceps central activation ratio (CAR) in patients with tibiofemoral osteoarthritis. METHODS Thirty-three participants with diagnosed tibiofemoral osteoarthritis were randomly allocated to the 45-min TENS treatment (six males and four females, 56 +/- 10.1 yr, 174.11 +/- 10.78 cm, 89.34 +/- 21.3 kg), the 20-min focal knee joint cooling treatment (six males and five females, 58 +/- 8.4 yr, 176.41 +/- 8.29 cm, 83.18 +/- 17.97 kg), or the control group (five males and seven females, 54 +/- 9.9 yr, 166.37 +/- 13.07 cm, 92.14 +/- 25.37 kg). Volitional quadriceps activation, maximal voluntary isometric contraction, and subjective pain measurements were conducted at baseline and at 20, 30, and 45 min. The 20-min focal knee joint cooling intervention consisted of two 1.5-L ice bags to the anterior and posterior aspects of the knee. The TENS group received 45 min of a sensory, biphasic square wave stimulation (150-mus phase duration and 150 pps) from four 2 x 2-inch electrodes positioned around the patella. RESULTS : TENS resulted in a significantly higher percent change in CAR scores compared with control at 20 min (6.4 +/- 4.8 vs -3.5 +/- 8, P = 0.006), 30 min (9.7 +/- 10.16 vs -1 +/- 7.9, P = 0.025), and 45 min (11.25 +/- 6.96 vs 0.81 +/- 9.4, P = 0.029). Focal knee joint cooling resulted in significantly higher percent change scores compared with the control group at 20 min (5.75 +/- 7.25 vs -3.5 +/- 8, P = 0.009) and trended to be higher at 45 min (9.06 +/- 9.63 vs 0.81 +/- 9.4, P = 0.098). No significant differences in percent change for CAR were found between the TENS and the focal knee joint cooling group. CONCLUSIONS Both TENS and focal knee joint cooling increased the quadriceps CAR immediately after application in participants with tibiofemoral osteoarthritis.

Intrarater reliability of the functional movement screen.

Abstract Gribble, PA, Brigle, J, Pietrosimone, BG, Pfile, KR, and Webster, KA. Intrarater reliability of the functional movement screen. J Strength Cond Res 27(4): 978–981, 2013—The Functional Movement Screen (FMS) is a tool that quantifies movement patterns as a way to detect performance asymmetries. Although previous study has investigated the reliability of FMS, no current research has examined intrarater reliability or how clinical experience plays a role in the reliability of this tool. In this controlled laboratory study design, repeated measures were used to investigate how experience using the FMS and clinical experience as an athletic trainer (AT) affects the intrarater reliability of FMS testing. Before the data collection, 3 individuals recruited from the university community provided signed informed consent to serve as videotaped models performing the FMS test. The participants (raters) in the study, with different levels of FMS and clinical experience, viewed each of the 3 videotaped models and rated the video models on each exercise of the FMS according to the script that was presented by one of the study investigators. A week later, the participants watched the same videos again, in a different randomized order, and rated each video model on each exercise. After the scores from the participants were collected from both sessions, the intersession scores of the FMS were examined to establish intrarater reliability of all the participants. Additionally, the intrarater reliability of different groups of clinicians and students was compared to make inferences about the influence of clinical experience as an AT along with previous experience using the FMS. The ATs with at least 6 months of experience using the FMS (ATExp group) had the strongest intrarater reliability [intraclass correlation coefficients, ICC (2,1): 0.946], followed by the AT group with moderate reliability [ICC (2,1): 0.771]. This study indicates that intrarater reliability is strong and seems to strengthen when the individuals have experience using the FMS in addition to clinical experience.

Effects of Transcutaneous Electrical Nerve Stimulation and Therapeutic Exercise on Quadriceps Activation in People With Tibiofemoral Osteoarthritis

STUDY DESIGN Blinded, randomized controlled trial. OBJECTIVES To determine if the combination of transcutaneous electrical nerve stimulation (TENS) set to a sensory level and therapeutic exercise would be more effective than the combination of placebo TENS and therapeutic exercises or therapeutic exercises only to increase quadriceps activation in individuals with tibiofemoral osteoarthritis. BACKGROUND Quadriceps activation deficits are common in those with tibiofemoral osteoarthritis, and TENS has been reported to immediately increase quadriceps activation. Yet the long-term benefits of TENS for motor neuron activation have yet to be determined. METHODS Thirty-six individuals with radiographically assessed tibiofemoral osteoarthritis were randomly assigned to the TENS and exercise, placebo and exercise, and exercise only groups. All participants completed a supervised 4-week lower extremity exercise program. TENS and placebo TENS were worn throughout the therapeutic exercise sessions, as well as during daily activities. Our primary outcome measures, quadriceps central activation ratio, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were evaluated at baseline and at 2 weeks and 4 weeks of the intervention. RESULTS Quadriceps activation was significantly higher in the TENS with exercise group compared to the exercise only group at 2 weeks (0.94 ± 0.04 versus 0.82 ± 0.12, P<.05) and the placebo and exercise group at 4 weeks (0.94 ± 0.06 versus 0.81 ± 0.15, P<.05). WOMAC scores improved in all 3 groups over time, with no significant differences among groups. CONCLUSION This study provides evidence that TENS applied in conjunction with therapeutic exercise and daily activities increases quadriceps activation in patients with tibiofemoral osteoarthritis and, while function improved for all participants, effects were greatest in the group treated with a combination of TENS and therapeutic exercises. LEVEL OF EVIDENCE Therapy, level 1b-.

Voluntary Quadriceps Activation Deficits in Patients with Tibiofemoral Osteoarthritis: A Meta-Analysis

The objective of this study was to assess the magnitude of quadriceps activation deficits in the involved extremity and contralateral extremity of patients with knee joint osteoarthritis (OA), as well as matched controls. An exhaustive search of the literature was performed using Web of Science between 1970 and February 24, 2010, using the search terms “osteoarthritis” AND “quadriceps activation” OR “quadriceps inhibition” and cross‐referencing pertinent articles. Studies written in English reporting quadriceps activation means and standard deviations in patients with tibiofemoral OA via a method using an exogenous electrical stimulation were evaluated for methodological quality and were included for data analysis. Fourteen individual studies met the criteria for inclusion into data analysis. The number of participants and mean activation levels were used to calculate weighted means for the involved limb (14 studies), the contralateral limb (from a subset of 6 studies), and an involved limb subset from only the studies evaluating the contralateral limb and population of control subjects (5 studies). Weighted means from the involved limb (82.2; 95% CI = 81.4‐83.3%), contralateral limb (81.7; 80.1‐83.3%), and involved limb subset (76.8; 74.8‐78.8%) groups were found to have lower volitional quadriceps activation compared with the control groups (90; 88.9‐91.7%). Although the weighted involved limb mean was not different from that of the contralateral limb, the mean and 95% confidence intervals for the involved limb subset were lower than that of the contralateral limb group, suggesting that the involved limb had less volitional activation within OA subjects. This provides evidence that bilateral quadriceps volitional activation deficits are present in persons with knee OA.

Chronic ankle instability and corticomotor excitability of the fibularis longus muscle

CONTEXT Neuromuscular deficits are common in people with chronic ankle instability (CAI). Corticomotor pathways are very influential in the production of voluntary muscle function, yet these pathways have not been evaluated in people with CAI. OBJECTIVE To determine if corticomotor excitability of the fibularis longus (FL) differs between individuals with unilateral CAI and matched control participants without CAI. DESIGN Case-control study. SETTING Laboratory. Patients or Other Participants: Ten people with CAI (4 men, 6 women; age = 21.2 ± 1.23 years, height = 175.13 ± 9.7 cm, mass = 77.1 ± 13.58 kg) and 10 people without CAI (4 men, ± women; age = 21.2 ± 2.3 years; height = 172.34 ± 8.86 cm, mass = 73.4 ± 7.15 kg) volunteered for this study. MAIN OUTCOME MEASURE(S) Transcranial magnetic stimulation was performed over the motor cortex on neurons corresponding with the FL. All testing was performed with the participant in a seated position with a slightly flexed knee joint and the ankle secured in 10 8 of plantar flexion. The resting motor threshold (RMT), which was expressed as a percentage of 2 T, was considered the lowest amount of magnetic energy that would induce an FL motor evoked potential equal to or greater than 20 l V, as measured with surface electromyography, on 7 consecutive stimuli. In addition, the Functional Ankle Disability Index (FADI) and FADI Sport were used to assess self-reported function. RESULTS Higher RMTs were found in the injured and uninjured FL of the CAI group (60.8% ± 8.4% and 59.1% ± 8.99%, respectively) than the healthy group (52.8% ± 8.56% and 52% ± 7.0%, respectively; F(1,18) = 4.92, P = .04). No leg x group interactions (F(1,18) = 0.1, P = .76) or between-legs differences (F(1,18) = 0.74, P = .40) were found. A moderate negative correlation was found between RMT and FADI (r = 0.4, P = .04) and FADI Sport (r = 0.44, P = .03), suggesting that higher RMT is related to lower self-reported function. CONCLUSIONS Higher bilateral RMTs may indicate deficits in FL corticomotor excitability in people with CAI. In addition, a moderate correlation between RMT and FADI suggests that cortical excitability deficits may be influential in altering function.

Focal knee joint cooling increases the quadriceps central activation ratio

Abstract The objective of this study was to evaluate the effects of a 20-min focal knee joint cooling intervention on quadriceps central activation ratio (CAR) in healthy volunteers. A counterbalanced, cross-over study assessed the effects of a focal joint cooling intervention compared with a control condition 3–14 days apart. Eleven healthy volunteers (6 males, 5 females; age 25 ± 5 years; height 1.71 ± 0.1 m, mass 77 ± 21 kg) were included in the final analysis. The joint cooling intervention consisted of two 1.5-litre ice bags applied to the knee joint for 20 min, in one of two counterbalanced sessions, completed 3–14 days apart. In the control session, participants sat quietly between the baseline and 20-min measurements. Quadriceps CAR was assessed at 70° of knee flexion at four instants (baseline, 20, 30, and 45 min). There was a significant treatment × time interaction (F 3,30 = 5.9, P = 0.003) and post hoc analyses revealed that CAR was higher in the focal knee joint cooling session than the control session at 20 min (0.79 ± 0.12 vs. 0.70 ± 0.12; t 10 = 3.9, P = 0.003) and 45 min (0.77 ± 0.10 vs. 0.69 ± 0.12; t 10 = 3.1, P = 0.01). The CAR tended to be higher during the experimental session than the control session at 30 min (0.79 ± 0.13 vs. 0.74 ± 0.11; t 10 = 2.1, P = 0.07).Volitional activation increased following focal knee joint cooling in healthy volunteers.

Patellofemoral Pain Syndrome Alters Neuromuscular Control and Kinetics during Stair Ambulation

The aim of the study was to investigate differences in frontal plane knee kinetics, onset timing and duration of the gluteus medius (GMed), adductor longus (AL), and vastus medialis oblique (VMO) during stair ambulation between those with and without patellofemoral pain syndrome (PFPS). Twenty PFPS patients and twenty healthy participants completed stair ambulation while surface electromyography (EMG), video, and ground reaction forces were collected. PFPS patients had a higher peak internal knee abduction moment during stair ascent, and a higher internal knee abduction impulse for both ascent and descent. During stair ascent, PFPS patients displayed earlier onset of the AL and later onset of GMed, compared to the healthy individuals. Also, PFPS patients had longer activation duration of the AL and shorter activation durations of the VMO and GMed during stair ascent. During stair descent, PFPS patients displayed delayed GMed onset and shorter activation duration of GMed and VMO. The results of the study suggest that altered neuromuscular control of the medial thigh musculature may be an important contributor to PFPS.

A systematic review of prophylactic braces in the prevention of knee ligament injuries in collegiate football players.

OBJECTIVE To determine the relative risk reduction associated with prophylactic knee braces in the prevention of knee injuries in collegiate football players. DATA SOURCES An exhaustive search for original research was performed using the PubMed, SportDiscus, and CINAHL databases from 1970 through November 2006, with the search terms knee brace, knee braces, knee bracing and football, prophylactic brace, and prophylactic knee braces. STUDY SELECTION Seven studies comparing knee injuries among braced and non-braced collegiate football players were included. Study methods were assessed using the Physiotherapy Evidence Database (PEDro) scale. PEDro scores ranged from 2 to 5. DATA EXTRACTION The number of participants and frequency of knee injuries were used to calculate the relative risk reduction or increase. DATA SYNTHESIS We found a relative risk reduction for 3 studies with point estimates of 10% (36% to -26%), 58% (25% to 76%), and 56% (13% to 77%). Four studies demonstrated an increased risk of injury, with point estimates of 17% (19% to -71%), 49% (-31% to -69%), 114% (23% to -492%), and 42% (-18% to -70%). CONCLUSIONS Data from existing research are inconsistent. Based on a Strength of Recommendation Taxonomy level of evidence of 2 with a grade B recommendation, we cannot conclusively advocate or discourage the use of prophylactic knee braces in the prevention of knee injuries in collegiate football players.

Motor-Neuron Pool Excitability of the Lower Leg Muscles After Acute Lateral Ankle Sprain

CONTEXT Neuromuscular deficits in leg muscles that are associated with arthrogenic muscle inhibition have been reported in people with chronic ankle instability, yet whether these neuromuscular alterations are present in individuals with acute sprains is unknown. OBJECTIVE To compare the effect of acute lateral ankle sprain on the motor-neuron pool excitability (MNPE) of injured leg muscles with that of uninjured contralateral leg muscles and the leg muscles of healthy controls. DESIGN Case-control study. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS Ten individuals with acute ankle sprains (6 females, 4 males; age= 19.2 ± 3.8 years, height= 169.4 ± 8.5 cm, mass= 66.3 ± 11.6 kg) and 10 healthy individuals(6 females,4 males; age= 20.6 ± 4.0 years, height = 169.9 ± 10.6 cm, mass= 66.3 ± 10.2 kg) participated. INTERVENTION(S) The independent variables were group (acute ankle sprain, healthy) and limb (injured, uninjured). Separate dependent t tests were used to determine differences in MNPE between legs. MAIN OUTCOME MEASURE(S) The MNPE of the soleus, fibularis longus, and tibialis anterior was measured by the maximal Hoffmann reflex (H(max)) and maximal muscle response (M(max)) and was then normalized using the H(max):M(max) ratio. RESULTS The soleus MNPE in the ankle-sprain group was higher in the injured limb (H(max):M(max) = 0.63; 95% confidence interval [Cl],0.46, 0.80) than the uninjured limb (H(max):M(max) = 0.47; 95%Cl, 0.08, 0.93)(t(6) = 3.62,P =.01).In the acute ankle-sprain group, tibialis anterior MNPE tended to be lower in the injured ankle (H(max):M(max) =0.06; 95% Cl, 0.01, 0.10) than in the uninjured ankle (H(max):M(max) =0.22; 95%Cl, 0.09, 0.35),but this finding was not different (t(9) =-2.01, P =.07). No differences were detected between injured (0.22; 95% Cl, 0.14, 0.29) and uninjured (0.25; 95%Cl, 0.12, 0.38) ankles for the fibularis longus in the ankle-sprain group (t(9) =-0.739, P =.48). We found no side-to-side differences in any muscle among the healthy group. CONCLUSIONS Facilitated MNPE was present in the involved soleus muscle of patients with acute ankle sprains, but no differences were found in the fibularis longus or tibialis anterior muscles.