Attacking 22 entries in rugby union: running demands and differences between successful and unsuccessful entries

Global Positioning System (GPS) technology is commonly utilized in team sports, including rugby union. It has been used to describe the average running demands of rugby union. This has afforded an enhanced understanding of the physical fitness requirements for players. However, research in team sports has suggested that training players relative to average demands may underprepare them for certain scenarios within the game. To date, no research has investigated the running demands of attacking 22 entries in rugby union. Additionally, no research has been undertaken to determine whether differences exist in the running intensity of successful and unsuccessful attacking 22 entries in rugby union. The first aim of this study was to describe the running intensity of attacking 22 entries. The second aim of this study was to investigate whether differences exist in the running intensity of successful and unsuccessful attacking 22 entries. Running intensity was measured using meters per minute (m min^-1 ) for (a) total distance, (b) running distance, (c) high-speed running distance, and (d) very high-speed running distance. This study provides normative data for the running intensity of attacking 22 entries in rugby union. Forwards achieved greater high-speed running intensity in successful (3.6 m min^-1 ) compared to unsuccessful (1.8 m min^-1 ) attacking 22 entries. Forwards should try and achieve greater high-speed running intensity in attacking 22 entries to increase the likelihood of successful outcomes during this period of gameplay.

Single-leg drop landing motor control strategies following acute ankle sprain injury

No research currently exists investigating the effect of acute injury on single-limb landing strategies. The aim of the current study was to analyze the coordination strategies of participants in the acute phase of lateral ankle sprain (LAS) injury. Thirty-seven participants with acute, first-time LAS and 19 uninjured participants completed a single-leg drop landing task on both limbs. Three-dimensional kinematic (angular displacement) and sagittal plane kinetic (moment-of-force) data were acquired for the joints of the lower extremity from 200 ms pre-initial contact (IC) to 200 ms post-IC. The peak magnitude of the vertical component of the ground reaction force (GRF) was also computed. Injured participants displayed a bilateral increase in hip flexion, with altered transverse plane kinematic profiles at the knee and ankle for both limbs (P < 0.05). This coincided with a reduction in the net-supporting flexor moment of the lower extremity (P < 0.05) and magnitude of the peak vertical GRF for the injured limb (21.82 ± 2.44 N/kg vs 24.09 ± 2.77 N/kg; P = 0.013) in injured participants compared to control participants. These results demonstrate that compensatory movement strategies are utilized by participants with acute LAS to successfully reduce the impact forces of landing.

Patellofemoral pain syndrome: a review on the associated neuromuscular deficits and current treatment options

BACKGROUND

Patellofemoral pain syndrome (PFPS) is a common clinical presentation. Various neuromuscular factors have been reported to contribute to its aetiology.

STUDY DESIGN

Systematic review

METHODS

A literature search was carried out from 1998 up to December 2007. Eligible studies were those that: (1) examined the effects of hip strengthening in subjects with PFPS; (2) examined the effects of physiotherapy treatment aimed at restoring muscle balance between the vastus medialis oblique (VMO) and vastus lateralis (VL) in subjects with PFPS; (3) examined the effect of taping on electromyogram (EMG) muscle amplitude in subjects with PFPS; and (4) compared the effects of open versus closed kinetic chain exercises in the treatment of subjects with PFPS.

RESULTS AND CONCLUSION

No randomised controlled trials exist to support the use of hip joint strengthening in subjects with PFPS. Physiotherapy treatment programmes appear to be an efficacious method of improving quadriceps muscle imbalances. Further studies are required to determine the true efficacy of therapeutic patellar taping. Both open and closed kinetic chain exercises are appropriate forms of treatment for subjects with PFPS.

Ankle function during hopping in subjects with functional instability of the ankle joint

A common mechanism of inversion injury involves a lateral movement producing a hypersupination of the ankle joint. To date, no study has investigated patterns of muscle activity, three-dimensional (3D) joint kinematics and kinetics simultaneously in a group of subjects with functional instability (FI) compared with a non-injured control group during a lateral hopping test. Twenty-six subjects with the subjective complaint of FI of the ankle joint and 24 non-injured healthy control subjects volunteered to participate in the study. We measured 3D lower limb kinematics, kinetics and surface electromyography (EMG) of the rectus femoris, tibialis anterior, peroneus longus and soleus muscle in all subjects during a lateral hop task for the period 200 ms pre- and post-initial contact (IC). FI subjects were observed to have a less-everted position of the ankle joint during the time period from 45 ms pre-IC to 95 ms post-IC (P<0.05). FI subjects were also found to have an increase in pre- and post-IC rectus femoris, tibialis anterior and solues EMG activity. The results suggest that subjects with FI exhibit changes in ankle joint movement and neuromuscular control that could predispose to further injury.