No differences in knee joint loading between individuals who had a medial or lateral meniscectomy: An ancillary study

BackgroundArthroscopic partial meniscectomy is a frequently undertaken procedure for traumatic meniscal injuries. The location of knee joint degeneration and long-term prognosis differs between knees who have had a medial or lateral meniscectomy. However, there is no evidence comparing knee loading following a medial or lateral meniscectomy during sporting tasks. This study compared knee loading during walking and running between individuals who either had a medial or lateral meniscectomy. Methods Knee kinematic and kinetic data were collected during walking and running in individuals three to twelve months post-surgery. Participants were grouped according to the location of surgery (medial, n=12, and lateral, n=16). An independent t-test compared knee biomechanics between the groups and Hedge’s g effects sizes were also conducted. Results External knee adduction and knee flexion moments were similar between groups for walking and running with negligible to small effect sizes (effect size, 0.08–0.30). Kinematic (effect size, 0.03-0.22) and spatiotemporal (effect size, 0.02-0.59) outcomes were also similar between the groups. Conclusions The lack of differences in surrogate knee loading variables between medial and lateral meniscectomy groups was unexpected. These findings suggest that combining groups in the short-term period following surgery is applicable. However, the data presented in this study cannot explain the differences in long-term prognosis between medial and lateral meniscectomies

Knee Offloading by Patients During Walking and Running After Meniscectomy

Background:Changes in knee loading have been reported after meniscectomy. Knee loading has previously been assessed during jogging and treadmill running rather than overground running, which could give altered results.Purpose/Hypothesis:The purpose of this study was to evaluate knee function during overground running and walking after meniscectomy. It was hypothesized that the affected limb would demonstrate higher external knee adduction moment, lower knee flexion moment (KFM), and lower knee rotation moment (KRM) compared with the contralateral limb and with healthy individuals.Study Design:Controlled laboratory study.Methods:Kinematic and kinetic data were collected during running and walking in individuals after a meniscectomy and healthy individuals. Total knee joint moments (TKJM) were calculated from the sagittal, frontal, and transverse knee moments. Isometric quadriceps strength, perceived knee function, and kinesiophobia were also assessed. A mixed linear model compared differences between the affected leg, the contralateral leg, and the healthy leg.Results:Data were collected on 20 healthy individuals and 30 individuals after a meniscectomy (mean ± SD, 5.7 ± 2.9 months postsurgery), with 12, 16, and 2 individuals who had medial, lateral, and both medial and lateral meniscectomy, respectively. The affected limb demonstrated lower TKJM (P < .001), KFM (P = .004), and KRM (P < .001) during late stance of walking compared with the healthy group. Lower TKJM and KFM were observed during running in the affected limb compared with the contralateral limb and healthy group. No significant differences were observed between contralateral and healthy limbs except for KRM during late stance of walking. Lower quadriceps strength was observed in the affected (P < .001) and contralateral limbs (P = .001) compared with the healthy group. Individuals after a meniscectomy also reported greater kinesiophobia (P = .006) and lower perceived knee function (31.1%; P < .001) compared with the healthy group.Conclusion:After meniscectomy, individuals who sustained a traumatic meniscal injury showed lower TKJM in the affected limb compared with the contralateral limb and healthy individuals. This decrease in TKJM can be attributed to altered knee-loading strategies in the sagittal and transverse planes.Clinical Relevance:Improving movement strategies, quadriceps strength, and kinesiophobia through rehabilitation approaches will allow individuals to load their knee appropriately when returning to sport

Player Perceptions and Biomechanical Responses to Tennis Court Surfaces: The Implications to Technique and Injury Risk

Elite tennis players are required to perform on a variety of tennis court surfaces which differ in mechanical characteristics, such as friction and hardness, influencing their performance and risk of injury. To understand the influence of surfaces on performance and injury risk, three studies were conducted to investigate tennis players’ perceptions and biomechanical responses during tennis-specific movements on different court surfaces. In study 1, tennis players perceptions of acrylic and clay courts were identified following a thematic inductive analysis of semi-structured interviews (n = 7) to develop of a series of visual analogue scales (VAS) to quantify perceptions during studies 2 and 3. Perceptions of predictability of the surface and players’ ability to slide and change direction emerged, in addition to anticipated perceptions of grip and hardness. Study 2 aimed to examine the influence of court surfaces and prior clay court experience on perceptions and biomechanical characteristics of tennis-specific skills. Perception, kinematic, insole pressure and mechanical data were collected on an acrylic and a clay court. In agreement with findings reported in study 1, lower mechanical friction and hardness on the clay court were perceived and accompanied by less predictability and greater difficulty to change direction whilst being easier to slide. As result of sliding, players’ adopted an altered technique on the clay court compared to the acrylic leading to reductions in loading provide evidence to explain lower injury risks previously reported on clay courts. Prior clay court experience did not influence players’ perceptions. However, biomechanical response to the clay surface differed, such that players with high clay court experiences contacted the ground with an everted foot, believed to contribute to controlling sliding. Differences in perception-response relationships were reported between experience groups suggesting players with greater clay court experience are better able to choose an appropriate response to improve their performance. Friction properties of the surface may change during play on clay courts due to player movements and sliding on the court. Therefore there may be areas of expected and unexpected changes to friction to which players must respond to. Study 3 aimed to examine the influence of changes in friction and players awareness of these changes on perceptions and biomechanical response. Compared with study 1 and 2, players found it more difficult to identify differences in perceived grip during study 3, possibly due the smaller mechanical friction differences reported. Unexpected reductions in friction produced greater initial ankle inversion angles compared to the expected decreases in friction, increasing players’ risk of injury. Lower horizontal and vertical loading rates were reported on the lower friction conditions where further sliding was reported; suggesting a reduced injury risk by allowing longer time spent applying the forces. This thesis has identified key perception variables that enabled a holistic understanding of perceptions and their interaction with biomechanical response. Mechanical friction was an important factor influencing players’ ability to slide. Sliding on clay resulted in altered loading characteristics, pressure distributions and kinematics potentially reducing players’ injury risk. Tennis players’ experience of clay courts does not influence their perceptions of the surface but the response that players adopt, which lower their risk of injury and increase performance. It is important when playing on a clay court that friction properties are maintained across the court during a tennis match as much as possible to reduce injury risks, due to the influence of unexpected changes to friction on perceptions and response

‘Probably just sexism’- gendered experiences of resource access in rugby

Research pertaining to the experiences of women in rugby is scarce, which, coupled with the limited visibility of the sport and difficulty accessing resources, suggest that women’s rugby remains undervalued. Indeed, evidence of such gender inequalities remains largely anecdotal, with little rigorous research undertaken to understand the perspectives of women in rugby. This study aimed to explore the experiences of a diverse cohort of rugby players in relation to their participation in the sport and their ability to access resources. Twenty UK-based rugby players (10 men, 9 women and 1 non-binary person aged 29.1 ± 8.3 years) from school, university, club, military, and semi-professional environments, volunteered to participate in semi-structured interviews (36 ± 12 minutes) discussing their rugby experiences in relation to their gender and playing level. Interviews were transcribed verbatim, and a reflexive thematic analysis was undertaken. A widespread under-prioritisation of women in rugby was highlighted. Gender biases were apparent in access to changing rooms, pitches, quality coaches, and playing opportunities, and were reportedly propagated at the managerial level. Irrespective of gender, some amateur players reported difficulty accessing a suitable rugby environment. Insufficient player numbers precluded the formation of second teams, often resulting in inexperienced players competing beyond their ability. Women’s rugby players experienced considerable gender bias. This exploratory study highlights a need to address such issues to protect player welfare. Interventions to change the culture in rugby clubs and increased representation of women in managerial positions in rugby are recommended to enact meaningful change

PATELLOFEMORAL JOINT FORCES DURING RUNNING IN MENISCECTOMISED KNEES

Meniscal injuries in sports are common and often require surgical treatment. Individuals who undergo a partial meniscectomy often complain of patellofemoral pain and later develop degenerative changes in the patella. This study compared peak patellofemoral joint (PFJ) stresses during running in those who have had a meniscectomy (both affected and contralateral limbs) with healthy individuals. Kinematic and kinetic data were collected during running and used to estimate PFJ stresses. Peak hip, knee, ankle angles and moments were calculated. PFJ stresses were lower in the affected limb compared to the contralateral limb and healthy group. The affected limb also demonstrated reduced knee and ankle moments compared to the healthy group. Reduced PFJ stresses following a meniscectomy are likely to be a result of a quadriceps avoidance strategy which is likely to be used to compensate for the quadriceps weakness and atrophy often reported following a meniscectomy. Reduced PFJ stresses, if prolonged, could lead to tissue atrophy and a greater risk of injury

The effect of footwear with a flexible ankle collar on function in individuals with chronic ankle instability

Individuals who develop chronic ankle instability (CAI) following a lateral ankle sprain (LAS) often experience diminished proprioception, reduced dynamic stability, and altered movement patterns during landing (e.g. increased plantar flexion and inversion angles) (Simpson et al., Citation2019).Using external supports (e.g. ankle braces or taping) may reduce the risk of recurrent ankle sprains. However, disadvantages include discomfort, impaired athletic performance, and taping often requires application by a skilled practitioner and loosens over time (Koyama et al., Citation2014).Soft ankle collars are increasingly popular in sporting footwear, but it is not currently known if these provide positive benefits in individuals with CAI. Complete contact between the collar and the skin over the ankle joint could improve known deficits and ankle motion in CAI (Burcal et al., Citation2017)

STATURE AND LOAD AFFECT THE WALK TO RUN TRANSITION SPEED

Military personnel are often required to march “in-step” while carrying heavy loads. For example, the two speeds required to complete the role fitness test for the British Army are close to the preferred walking speed and preferred walk-to-run transition speed (PTS) for healthy adults when unloaded. PTS depends on anthropometry, including stature. Walking at speeds markedly different to PTS has been associated with increased metabolic cost and increased joint loading. There is also limited research into how this PTS is affected by load carriage. To minimise the risk of injury, there is a need to understand how load carriage affects PTS. This study found PTS for male and female personnel decreased with increased load carried, and that female personnel tended to transition from walking to running earlier than male personnel. The relationship between PTS and stature became more positive as load increased, irrespective of sex. Due to the association between deviating from preferred walking gait and increases in joint loading, these findings may have implications for the risk of injury in military personnel who are required to march “in-step”

No differences in knee joint loading between individuals who had a medial or lateral meniscectomy: An ancillary study

BackgroundArthroscopic partial meniscectomy is a frequently undertaken procedure for traumatic meniscal injuries. The location of knee joint degeneration and long-term prognosis differs between knees who have had a medial or lateral meniscectomy. However, there is no evidence comparing knee loading following a medial or lateral meniscectomy during sporting tasks. This study compared knee loading during walking and running between individuals who either had a medial or lateral meniscectomy.MethodsKnee kinematic and kinetic data were collected during walking and running in individuals three to twelve months post-surgery. Participants were grouped according to the location of surgery (medial, n = 12, and lateral, n = 16). An independent t-test compared knee biomechanics between the groups and Hedge’s g effects sizes were also conducted.ResultsExternal knee adduction and knee flexion moments were similar between groups for walking and running with negligible to small effect sizes (effect size, 0.08–0.30). Kinematic (effect size, 0.03–0.22) and spatiotemporal (effect size, 0.02–0.59) outcomes were also similar between the groups.ConclusionsThe lack of differences in surrogate knee loading variables between medial and lateral meniscectomy groups was unexpected. These findings suggest that combining groups in the short-term period following surgery is applicable. However, the data presented in this study cannot explain the differences in long-term prognosis between medial and lateral meniscectomies

Knee Offloading by Patients During Walking and Running After Meniscectomy

Background:: Changes in knee loading have been reported after meniscectomy. Knee loading has previously been assessed during jogging and treadmill running rather than overground running, which could give altered results. Purpose/Hypothesis:: The purpose of this study was to evaluate knee function during overground running and walking after meniscectomy. It was hypothesized that the affected limb would demonstrate higher external knee adduction moment, lower knee flexion moment (KFM), and lower knee rotation moment (KRM) compared with the contralateral limb and with healthy individuals. Study Design:: Controlled laboratory study. Methods:: Kinematic and kinetic data were collected during running and walking in individuals after a meniscectomy and healthy individuals. Total knee joint moments (TKJM) were calculated from the sagittal, frontal, and transverse knee moments. Isometric quadriceps strength, perceived knee function, and kinesiophobia were also assessed. A mixed linear model compared differences between the affected leg, the contralateral leg, and the healthy leg. Results:: Data were collected on 20 healthy individuals and 30 individuals after a meniscectomy (mean ± SD, 5.7 ± 2.9 months postsurgery), with 12, 16, and 2 individuals who had medial, lateral, and both medial and lateral meniscectomy, respectively. The affected limb demonstrated lower TKJM (P < .001), KFM (P = .004), and KRM (P < .001) during late stance of walking compared with the healthy group. Lower TKJM and KFM were observed during running in the affected limb compared with the contralateral limb and healthy group. No significant differences were observed between contralateral and healthy limbs except for KRM during late stance of walking. Lower quadriceps strength was observed in the affected (P < .001) and contralateral limbs (P = .001) compared with the healthy group. Individuals after a meniscectomy also reported greater kinesiophobia (P = .006) and lower perceived knee function (31.1%; P < .001) compared with the healthy group. Conclusion:: After meniscectomy, individuals who sustained a traumatic meniscal injury showed lower TKJM in the affected limb compared with the contralateral limb and healthy individuals. This decrease in TKJM can be attributed to altered knee-loading strategies in the sagittal and transverse planes. Clinical Relevance:: Improving movement strategies, quadriceps strength, and kinesiophobia through rehabilitation approaches will allow individuals to load their knee appropriately when returning to sport. Registration:: NCT03379415 (ClinicalTrials.gov identifier)

Biomechanical responses to changes in friction on a clay court surface

Objectives: To examine the influence of clay court frictional properties on tennis players’ biomechanical response. Design: Repeated measures Methods: Lower limb kinematic and force data were collected on sixteen university tennis players during 10 x 180° turns (running approach speed 3.9 ± 0.20 m.s-1) on a synthetic clay surface of varying friction levels. To adjust friction levels the volume of sand infill above the force plate was altered (kg per m2 surface area; 12, 16 and 20 kg.m-2). Repeated measures ANOVA and Bonferroni’s corrected alpha post-hoc analyses were conducted to identify significant differences in lower limb biomechanics between friction levels. Results: Greater sliding distances (ŋp2= 0.355, p = 0.008) were observed for the lowest friction condition (20 kg.m-2) compared to the 12 and 16 kg.m-2 conditions. No differences in ankle joint kinematics and knee flexion angles were observed. Later peak knee flexion occurred on the 20 kg.m-2 condition compared to the 12 kg.m-2 (ŋp2 = 0.270, p = 0.023). Lower vertical (ŋp2 = 0.345, p = 0.027) and shear (ŋp2 = 0.396, p = 0.016) loading rates occurred for the 20 kg.m2 condition compared to the 16 kg.m2. Conclusions: Lower loading rates and greater sliding distances when clay surface friction was reduced suggests load was more evenly distributed over time reducing players’ injury risks. The greater sliding distances reported were accompanied with later occurrence of peak knee flexion, suggesting longer time spent braking and a greater requirement for muscular control increasing the likelihood of fatigue