The use of knee braces prophylactically is still considered as an approach for injury mitigation for those in high-risk sporting activities, though their use is not fully supported. The purpose of this thesis was to examine biomechanical and neuromuscular effects of prophylactic brace wear following standardized repetitive exercise. Twelve participants participated and acted as their own control. The participants were required to participate in two sessions, one control session with no brace and one intervention session with the application of a off-the-shelf prophylactic knee brace. Pre-and post-exercise intervention single leg drop landings were recorded to examine the effects of an acute exercise stimulus on the neuromuscular and biomechanical effects of brace wear. Additionally, trials were collected at 30-minutes post-exercise to examine residual effects of the brace wear on landing kinematics and kinetics. Difference tests using analysis of variance (ANOVA) showed that there was a minimal effect of the prophylactic knee brace on biomechanical and neuromuscular variables following exercise as well as 30-minutes following knee brace removal. Further research may be required to identify if braces can be worn prophylactically to reduce the risk of injury during activity.

Abstract Aim: The main objective of this study was to compare electro mechanical delay (EMD) and rate of torque development (RTD) of the knee extensors 6 weeks after rehabilitation of anterior cruciate ligament reconstruction (ACLR) with or without neuromuscular electrical stimulation (NMES). Further the feasibility of the study was examined. Method: 10 participants were randomized into two groups, one neuromuscular electrical stimulation group (NMESG) and one training group (TG). The NMESG used a NMES-device as a complement to the ordinary rehabilitation protocol. Regular meetings with a physiotherapist were scheduled during the rehabilitation. Measurements of RTD and EMD during knee extension were made in an isokinetic dynamometer with electromyography recordings (EMG) from the knee extensors 6 weeks after surgery. Results: All participants completed the study. The NMESG went to see the physiotherapist 6.7 ± 2.5 times and the TG 6.8 ± 1.8 times. The participants in the NMESG used the NMES-apparatus 28 ± 1.7 times. Total number of training days for the NMESG was 25 ± 4 and for the TG 35 ± 1. RTD did not significantly differ between the groups. For the TG, RDT was 901.1, 941.2 and 531.0 Nm/s, over the first 50, 100 and 200 ms, respectively. For NMESG: RTD was 824.3, 966.2 and 529.0 Nm/s, over the first 50, 100 and 200 ms, respectively. No significant difference between the groups or interaction between group and muscle was found in EMD. For both groups EMD was significantly larger for vastus medialis as compared to the vastus lateralis and rectus femoris. Conclusions: The study was feasible to perform, and despite fewer training days for the NMESG, no significant group differences were found in RTD or EMD. A larger study population is needed to evaluate the efficacy of the intervention. / Abstrakt Syfte: Huvudsyftet med denna studie var att jämföra elektromekaniska fördröjning (EMD) och vridmoment utveckling (RTD) för knäextensorerna 6 veckor efter rehabilitering av främre korsbandsrekonstruktion (ACLR) med eller utan neuromuskulär elektrisk stimulering (NMES). Vidare undersöktes genomförbarheten av studien. Metod: 10 deltagare randomiseras in i två grupper, en neuromuskulär elektrisk stimulerings grupp (NMESG) och en träningsgrupp (TG). NMESG använde en NMES - enhet som ett komplement till ordinarie rehabiliteringsprotokoll. Regelbundna möten med sjukgymnast var inplanerad under rehabiliteringen. Mätningar av RTD och EMD under knäets extension gjordes i en isokinetisk dynamometer med elektromyografi inspelningar (EMG) från knäextensorerna 6 veckor efter operationen. Resultat: Alla deltagare fullföljde studien. NMESG träffade sjukgymnasten 6,7 ± 2,5 gånger och TG 6,8 ± 1,8 gånger. Deltagarna i NMESG använde NMES - apparaten 28 ± 1,7 gånger. Totalt antal träningsdagar för NMESG var 25 ± 4 och för TG 35 ± 1. RTD skiljde sig inte signifikant mellan grupperna. För TG var RDT 901,1, 941,2 och 531,0 Nm/s, under de respektive första 50, 100 och 200 ms. För NMESG var RTD 824,3, 966,2 och 529,0 Nm/s, under de respektive första 50, 100 och 200 ms. Inga signifikanta skillnader mellan grupperna eller samspel mellan grupp och muskler hittades i EMD. För båda grupperna var EMD signifikant större för vastus medialis jämfört vastus lateralis och rectus femoris. Slutsats: Studien var möjligt att utföra, och trots färre träningsdagar för NMESG sågs inga signifikanta skillnader mellan grupperna i RTD eller EMD. Det behövs en större studiepopulation för att utvärdera effekten av interventionen.

Po priekinio kryžminio raiščio (PKR) rekonstrukcijos fizinio aktyvumo atgavimas trunka nuo 3 iki 12 mėnesių. Siekiant greitesnio kelio sąnario funkcijos atkūrimo, šiame darbe vertinamas dviejų skirtingų metodikų efektyvumas. Darbo tikslas – palyginti raumenų elektrostimuliacijos (RES), taikomos kineziterapijos metu ir prieš kineziterapijos procedūrą, poveikį kelio sąnario funkcijos atkūrimui po priekinio kryžminio raiščio rekonstrukcinės operacijos. Apžvelgus mokslinę literatūrą numatytą mokslinio darbo tikslą pasiekti buvo iškelti 3 uždaviniai. Pirmuoju uždaviniu siekiama įvertinti kelio sąnario funkcijos kitimą po priekinio kryžminio raiščio rekonstrukcinės operacijos taikant raumenų elektrostimuliaciją prieš kineziterapijos procedūras. Antrasis uždavinys skirtas įvertinti kelio sąnario funkcijos kitimą po priekinio kryžminio raiščio rekonstrukcinės operacijos taikant raumenų elektrostimuliaciją kineziterapijos procedūros metu. Trečiuoju uždaviniu siekiama palyginti kelio sąnario funkcijos atkūrimo pokytį po priekinio kryžminio raiščio rekonstrukcinės operacijos taikant raumenų elektrostimuliaciją kineziterapijos metu ir prieš kineziterapijos procedūrą. Tyrimo metodai: 1. Judesių amplitudė per kelio sąnarį vertinta goniometrijos metodu. 2. Blauzdą lenkiančių ir tiesiančių raumenų jėga vertinta Medicininių tyrimų tarnybos skale. 3. Skausmo intensyvumui vertinti naudota Skaičių analoginė skausmo skalė. 4. Kelio sąnario funkcinė būklė vertinta Lysholm klausimynu. 5. Operuotos... [toliau žr. visą tekstą] / After anterior cruciate ligament (ACL) reconstruction physical activity recovery lasts from 3 to 12 months. Seeking more rapid knee joint function recovery the effectiveness of two different methods are estimated in this research. The aim of the research is to compare the effectiveness of neuromuscular electrical stimulation (NMES) applied before and during physiotherapy procedure, as well as the effect of the knee joint function recovery after anterior cruciate ligament reconstruction. After review of scholarly literature there were 3 tasks set to reach the aim of the research. The first task is to estimate the changes in the knee joint function after anterior cruciate ligament reconstruction applying neuromuscular electrical stimulation before physiotherapy procedures. The second task is to estimate the changes in the knee joint function after anterior cruciate ligament reconstruction applying neuromuscular electrical stimulation during physiotherapy procedures. The third task is to compare the changes in the knee joint function applying neuromuscular electrical stimulation during physiotherapy and before physiotherapy procedure. The methods of the research: 1. The amplitude of the knee joint movements is estimated by goniometry method. 2. The force of the calf flexor and extensor muscles is estimated by Medical Research Council scale. 3. The intensity of the pain is estimated by Numeric Rating Scale. 4. The knee joint function is assessed by Lysholm knee questionnaire. 5... [to full text]

Darbo tikslas: įvertinti jauno amžiaus, fiziškai aktyvių asmenų, patyrusių kelio sąnario priekinių kryžminių raiščių plyšimą apatinių galūnių funkcinius rodiklius. Uždaviniai: 1) įvertinti vyrų ir moterų apatinių galūnių funkcijos rodiklius po PKR rekonstrukcijos uždaroje kinetinėje grandyje atliekant horizontalius šuolių testus; 2) Nustatyti vyrų ir moterų po PKR rekonstrukcijos judesio stereotipo ypatybes uždaroje kinetinėje grandyje atliekant vertikalius šuolių testus; 3) įvertinti vyrų ir moterų dinaminės pusiausvyros rodiklius po PKR rekonstrukcijos; 4) palyginti vyrų ir moterų operuotos kojos funkcijos rodiklius su sveikosios kojos rodikliais po PKR rekonstrukcijos. Tiriamieji ir metodika: tyrime ištirti 38 jauno amžiaus asmenys iš kurių 30 – vyrai (28,77 ± 7,9 metai) ir 8 moterys (26,50 ± 7,1 metai). Tiriamieji buvo padalinti į dvi grupes: 30 vyrų bei 8 moterys ir atliktas vienkartinis testavimas (tiriamiesiems buvo vertinama tiek operuota, tiek sveika koja). Siekiant įvertinti jauno amžiaus fiziškai aktyvių asmenų kelio sąnario funkcinę būklę buvo naudojami šie funkciniai testai: nužengimo nuo pakylos ir maksimalaus šuolio testas, dinaminio stabilumo “Y” testas bei šuolių viena koja testas. Tyrimo rezultatai ir išvados: 1. Įvertinus vyrų, patyrusių priekinių kryžminių raiščių traumą funkcinę apatinių galūnių būklę šuolių viena koja testais nustatyta, jog operuotosios kojos rodikliai buvo mažesni nei sveikosios tik trijų maksimalių šuolių viena koja testo metu. Moterų... [toliau žr. visą tekstą] / Aim: to assess the lower limbs’ function indexes of young active people, who suffered a tear of anterior cruciate ligament. Objectives: 1) to assess the lower limbs’ function indexes of females and males after the ACL reconstruction in a close kinetic chain with horizontal hop tests; 2) to identify peculiarities of movement stereotype of females and males after the ACL reconstruction in a close kinetic chain with vertical hop tests; 3) to assess the dynamic balance indexes of females and males after the ACL reconstruction; 4) to compare indexes of the leg after the ACL reconstruction surgery of females and males with ones of a healthy leg. Respondents and methodology: 38 young people, inc. 30 males (28,77 ± 7,9 y. o. ) and 8 females (26,50 ± 7,1 y. o. ). The respondents were divided into two groups: 30 males and 8 females and have underwent a single test (for a leg after surgery and a healthy one). In order to assess the lower limbs’ function indexes of young active people, the following tests have been used: drop vertical jump test, dynamic stability “Y” test and single leg hop test. Results and conclusions: 1. After assessment of the lower limbs’ function of males, who suffered a tear of anterior cruciate ligament with single leg hop tests, it has been identified that indexes of a leg after surgery were lower, compared to a healthy one only during the test of three maximum single leg hop test. Functional indexes of lower limbs for females were the same. 2. According to the... [to full text]

No description available.

Study Design: Methodological study. Objectives: To examine the agreement and validity of using observational risk screening guidelines to evaluate ACL injury risk factors. Background: Post-pubescent females have an increased risk of anterior cruciate ligament (ACL) injury compared with their male counterparts partly due to their high-risk landing and cutting strategies. There are currently no scientifically-tested methods to screen for these high risk strategies in the clinic or on the field. Methods and Measures: Three physiotherapists used observational risk screening guidelines to rate the neuromuscular characteristics of 40 adolescent female soccer players. Drop jumps were rated as high risk or low risk based on the degree of knee abduction. Side hops and side cuts were rated on the degree of lower limb 'reaching'. Ratings were evaluated for intrarater and interrater agreement using kappa coefficients. 3D motion analysis was used as a gold standard for determining the validity of ratings. Results: Acceptable intrarater and interrater agreement (k≥0.61) were attained for the drop jump and the side hop, with kappa coefficients ranging from 0.64 to 0.94. Acceptable sensitivity (≥0.80) was attained for the side hop and the side cut, with values ranging from 0.88 to 1.00. Acceptable specificity (≥0.50) was attained for the drop jump, with values ranging from 0.64 to 0.72. Conclusion: Observational risk screening is a practical and cost-effective method of screening for ACL injury risk. Based on levels of agreement and sensitivity, the side hop appears to be a suitable screening task. Agreement was acceptable for the drop jump but its validity needs further investigation.

"This research aimed to explore and better understand intervention protocols and their effect on lower limb control associated with anterior cruciate ligament (ACL) injury. A fundamental and unique aspect of this investigation was to establish a lab-based testing protocol that successfully mimicked actual game play. [...]This research validated a lab-based measure that best mimicked game-play to use as a pre- and post- testing measure for two common methods used in current ACL intervention strategies. In addition, further understanding of the effects of a landing training and dynamic balance training program were found." / Doctor of Philosphy

"This research aimed to explore and better understand intervention protocols and their effect on lower limb control associated with anterior cruciate ligament (ACL) injury. A fundamental and unique aspect of this investigation was to establish a lab-based testing protocol that successfully mimicked actual game play. [...]This research validated a lab-based measure that best mimicked game-play to use as a pre- and post- testing measure for two common methods used in current ACL intervention strategies. In addition, further understanding of the effects of a landing training and dynamic balance training program were found." / Doctor of Philosphy

Female athletes are known to have a higher rate of ACL injuries than male athletes in similar sports. Anatomical, neuromuscular, and strength factors have all been proposed as potential causes of this difference. The purpose of this investigation was to determine, through a series of three studies, the magnitude of sex differences, which exist in these potential risk factors. The first study investigated sex differences in anatomical risk factors. Male and female athletes from the Queensland Academy of Sport (Basketball: M = 14; F = 16; Soccer: F = 14) as well as the Men’s Lions Soccer club (n = 10) were recruited to participate in the study. A physical examination was completed which included: anthropometric measurements; lower extremity alignment measurements such as Q-Angle, knee recurvatum, and foot pronation; knee ligamentous laxity and muscle flexibility measurements; intercondylar notch width measurements using MRI; and an orthopedic examination. Our investigation found that anatomical differences do exist between healthy uninjured male and females. Females had larger Q-Angles, excessive foot pronation, decreased intercondylar notch width and increased ligamentous laxity and muscular flexibility compared to males. However, when examining the likely magnitude of these difference between the sexes, only a moderate effect was found (0.60 < ES ≤ 1.2). The second study investigated sex differences in strength measures that included knee flexion and extension peak torque values as measured using an isokinetic dynamometer, thigh muscle volume and cross sectional area (CSA) determined by Magnetic Resonance Imaging (MRI), and single leg hop for distance. Male and female athletes were recruited from the Queensland Academy of Sport (QAS) basketball program (M= 13; F = 13). Males were found to be significantly stronger than females even when all strength measurements were normalized to account for sex differences in anthropometrics (p < 0.05). Males generated greater peak forces in their knee extensors and flexors, greater hop distances and had larger muscle volumes and maximal cross sectional areas as determined by MRI analysis. When examining the likely magnitude of these difference between the sexes, a moderate to large effect was found (1.00 < ES ≤ 2.8). The final study investigated sex differences in lower limb neuromuscular factors, viz: body-segmental motions; ground reaction forces; and muscle timing and recruitment patterns in response to a drop-landing task in a laboratory setting. Participants recruited for the study were male and female university students (M= 11, F = 11), currently attending the University of Queensland. Participants performed a drop-landing task that consisted of performing a total of eight vertical drop landings from a box, 40cm in height, onto a force platform. Lower extremity sagittal plane marker kinetics and kinematics for the hip, knee and ankle were collected to determine joint angles at impact of landing and then maximum angle reached, ROM from initial ground contact to maximum angle as well as joint angular velocities. Thigh muscle activation patterns (i.e. recruitment order) in response to the drop-landing task were also collected. Results found that the female group landed with decreased knee flexion angles and higher ground reaction forces per body weight during the impact of landing compared to the males. After initial impact, the females also reached the greatest angles at the hip and knee therefore producing the greatest ROM at these joints. In regards to thigh muscle activation patterns, both male and female groups activated the hamstring muscles, prior to quadriceps activation, a result that was not expected. In conclusion, several anatomical, neuromuscular and strength differences exist between male and female athletes with the greatest differences observed in the kinematic and strength data. Females could potentially best benefit from training programs that include strength and proprioception components as well as technique awareness in an attempt to reduce the current ACL incidence rates observed in female athletes.

Doctor of Philosophy / The aim of the work presented in this thesis was to examine the associations between the kinematics of the knee characterised by the tibiofemoral contact pattern, and degenerative change, in the context of anterior cruciate ligament (ACL) injury. While the natural history of degenerative change following knee injury is well understood, the role of kinematics in these changes is unclear. Kinematics of the knee has been described in a variety of ways, most commonly by describing motion according to the six degrees of freedom of the knee. The advantage of mapping the tibiofemoral contact pattern is that it describes events at the articular surface, important to degenerative change. It was hypothesised that the tibiofemoral contact pattern would be affected by injury to the knee. A model of ACL injury was chosen because the kinematics of the knee have been shown to be affected by ACL injury, and because the majority of chronic ACL-deficient knees develop osteoarthritis, the associations between kinematics and degenerative change could be explored. A technique of tibiofemoral contact pattern mapping was established using MRI, as a quantifiable measure of knee kinematics. The tibiofemoral contact pattern was recorded from 0º to 90º knee flexion while subjects performed a leg-press against a 150N load, using sagittal magnetic resonance imaging (MRI) scans. The technique was tested and found to be reliable, allowing a description of the tibiofemoral contact pattern in 12 healthy subjects. The tibiofemoral contact patterns of knee pathology were then examined in a series of studies of subjects at a variety of stages of chronicity of ligament injury and osteoarthritis. Twenty subjects with recent ACL injury, 23 subjects with chronic ACL deficiency of at least 10 years standing, and 14 subjects with established osteoarthritis of the knee were recruited. The 20 subjects with recent ACL injury were examined again at 12 weeks and 2 years following knee reconstruction. The tibiofemoral contact patterns were examined for each group of subjects and the associations between changes in the contact patterns and evidence of joint damage explored. Evidence of joint damage and severity of osteoarthritis were recorded from xrays, diagnostic MRI, operation reports and bone densitometry at the tibial and femoral condyles of the knee. Each of the three groups with knee pathology exhibited different characteristics in the tibiofemoral contact pattern, and these differences were associated with severity of joint damage and osteoarthritis. The recently ACL-injured knees demonstrated a tibiofemoral contact pattern that was posterior on the tibial plateau, particularly in the lateral compartment. Those with chronic ACL deficiency demonstrated differences in the contact pattern in the medial compartment, associated with severity of damage to the knee joint. Osteoarthritic knees showed reduced femoral roll back and longitudinal rotation that normally occur during knee flexion. Two years following knee reconstruction there was no difference between the contact pattern of the reconstructed and healthy contralateral knees. This technique of tibiofemoral contact pattern mapping is sensitive to the abnormal characteristics of kinematics in ligament injury and osteoarthritis. This is the first time the tibiofemoral contact characteristics of chronic ACL-deficient and osteoarthritis knees have been described and links examined between tibiofemoral contact patterns and degenerative change.