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Timothy F. Tyler,Stephen J. Nicholas, Steven J. Lee, Michael Mullaney and Malachy P. McHugh

Internal impingement syndrome has been limked to glenohumeral internal rotation deficit (GIRD) and posterior shoulder tightness. The aim of the study was to discover if increases in internal rotation and decreased posterior shoulder tightness result in improved impingement symptoms.

22 patients with internal impingement were assessed for passive internal rotation and external rotation (ER) range of motion (ROM) at 90° of shoulder abduction and posterior shoulder tightness (cross-chest adduction in side lying). The Simple Shoulder Test (SST) was administered on initial evaluation and discharge.

The following treatment involved stretching and mobilising the posterior shoulder. Changes in GIRD, ER ROM, and posterior shoulder tightness were compared between patients with complete resolution of symptoms versus patients with residual symptoms.

Patients had significant GIRD (35°), loss of ER ROM (23°), and posterior shoulder tightness (35°) on initial evaluation. Physical therapy improved GIRD, ER ROM loss, and posterior shoulder tightness. The SST improved from 5 ± 3 to 11 ± 1. A greater improvement in posterior shoulder tightness was seen in patients with complete resolution of symptoms compared with patients with residual symptoms. Improvements in GIRD and ER ROM loss were not different between groups.

Resolution of symptoms after physical therapy treatment for internal impingement was related to correction of posterior shoulder tightness but not correction of GIRD.

Am J Sports Med January 2010 38:114-119

Marie A. Johanson, Brian J. Cuda, Jonathan E. Koontz, Julia C. Stell, Thomas A. Abelew

Stretching exercises are frequently assigned to individuals with reduced flexibility of the gastrocnemius muscle.  This study aimed to determine the effect of stretching the gastrocnemius muscle on ankle dorsiflexion, knee extension, and muscle activity during gait.

Testing took place in a biomechanical laboratory where 16 volunteers (9 men and 7 women) with under 5° of passive ankle-dorsiflexion range of motion were randomly assigned to either an experimental or control group.  The experimental group were given a gastrocnemius stretching programme for 3 weeks. Measurements taken before and after the 3 week period were: maximum ankle dorsiflexion, maximum knee extension, and EMG amplitude of the gastrocnemius muscle between heel strike and heel-off.

The results demonstrated that there was no significant effect of group or time on maximum ankle dorsiflexion, maximum knee extension, or EMG activity of the gastrocnemius muscle between heel strike and heel-off. The experimental group did however, display significantly greater passive ankle-dorsiflexion range of motion after intervention than the control group.

The authors conclude that stretching did not alter joint angles or gastrocnemius muscle activity in the early to midstance phase of gait. It did however increase the range of passive dorsiflexion at the ankle.

Journal of Sport Rehabilitation, 18(4), November 2009

Kimberly S. Peer, EdD, ATC, LAT; Jacob E. Barkley, PhD; and Danielle M. Knapp, BS

The aim of this research was to see if biomechanical muscle stimulation (BMS) applied directly to different parts of the body using the Swisswing^® device causes improvements in range of motion and perceived stiffness in active adults with acute or subacute ankle sprains or hamstring strains.

Two separate groups of individuals with grade 1 or 2 ankle sprain or hamstring strain underwent 20 minutes of a controlled therapy consisting of ice, compression, and elevation, and 10 minutes of segmental BMS using the Swisswing^® at 20 Hz. Ankle & hamstring flexibility, and subjective ratings of stiffness were assessed prior to control treatment (baseline), post-control treatment, and post-Swisswing^® treatment.

The results showed that Swisswing^® treatment significantly improved ankle dorsiflexion and eversion as well as hamstring flexibility, and significantly reduced perceived ankle and hamstring stiffness.

The study concludes that BMS therapy using the Swisswing^® can have significant acute benefits for improving flexibility and reducing perceived stiffness in ankle or hamstring injury. Future research is needed to determine the duration of these effects and if repeated treatment aids in long-term injury recovery.

The Physician and Sportsmedicine: Volume 37: No.4
 

Torbjørn Soligard, Grethe Myklebust, Kathrin Steffen, Ingar Holme, Holly Silvers, Mario Bizzini, Astrid Junge, Jiri Dvorak, Roald Bahr, Thor Einar Andersen. 

The aim of the study was to examine the effect of a comprehensive warm-up programme designed to reduce the risk of injuries in female youth football.

125 football clubs from Norway (65 clusters in the intervention group; 60 in the control group) were followed for one league season. This totalled 1892 female players aged 13-17 (1055 players in the intervention group; 837 players in the control group).

The intervention group were given a comprehensive warm-up programme to improve strength, awareness, and neuromuscular control during static and dynamic movements. Results were measured by injuries to the lower extremity (foot, ankle, lower leg, knee, thigh, groin, and hip).

The results demonstrated that 264 players had relevant injuries: 121 players in the intervention group and 143 in the control group. In the intervention group there was a significantly lower risk of injuries overall, overuse injuries, and severe injuries.

The authors concluded that although reduction in lower extremity injuries did not reach significance, the risk of severe injuries, overuse injuries, and injuries overall was reduced. This indicates that a structured warm-up programme can prevent injuries in young female football players.

BMJ 2008;337:a2469

R T H Cheung, G Y F Ng

Delayed onset of the vastus medialis obliquus (VMO) has often been linked with patellofemoral pain (PFP). Research has also suggested that lower leg movements play a role in patella tracking. Studies have also revealed that a motion control shoe could reduce rearfoot pronation in overpronators.  Using all of this information, the authors hypothesised that motion control shoes may help prevent PFP by controlling excessivepronation. This study compares the vasti muscle activities in people with excessive foot pronation when runningwith different trainers.

Twenty female subjects with rearfoot pronation >6° were selected. Testing involved treadmill running for 10 km on two separate days. The subjects wore a motion-control running shoe on one day and a neutral running shoe on the other. EMG activity of their right VMO and vastus lateralis (VL) were recorded. Their EMG onset timing and median frequency (MF) were compared between the two shoe conditions.

A more significant delay in VMO contraction onset of the running cycle occurred in the neutral shoe than in the motion control shoe. In the neutral shoe, the delay in VMO increased as mileage increased. This did not happen in the motion control shoe. A significant drop in MF of the quadriceps after the 10 km run in both shoes  was observed, and there was a larger drop in VMO MF when running with the neutral shoe. The findings suggest that the motion control shoe may facilitate a stable temporal activation of VMO during running.

British Journal of Sports Medicine 2009;43:943-947

LEE, MARCUS J. C.; REID, SIOBHAN L.; ELLIOTT, BRUCE C.; LLOYD, DAVID G.

Following an intial hamstring injury, re-injury is a common problem. The functional reasons for this remain unclear. This study looks at differences in swing phase running biomechanics and isokinetic strength, between the previously hamstring-injured and uninjured limbs of male athletes involved in sprint-based sports.

Athletes, underwent 3D motion analysis to determine bilateral joint kinematics and kinetics during submaximal sprinting. Various hip and knee isokinetic strength tests were performed bilaterally using a Biodex dynamometer. Peak torque (PT) and total work (TW; normalized to body mass) were collected isokinetically from concentric hamstrings (CH), concentric quadriceps (CQ), concentric hip flexors (CHF), and eccentric hamstrings (EH). Three PT and TW ratios were created, namely, CH/CQ, EH/CQ, and EH/CHF, and were compared between the previously injured and uninjured limbs.

The results show that lower limb swing phase kinematics and kinetics were similar. Only peak hip flexion angle in late swing was significantly reduced (1.9[degrees]) in the previously injured limb. EH PT was decreased and occurred at shorter hamstring lengths on the previously injured side, whereas CQ TW was increased by 13.6 Jkg-1. EH/CQ and EH/CHF ratios for PT and TW were reduced on the previously injured limbs.

The rearch concluded that although swing phase biomechanics of submaximal sprinting were similar between limbs, the previously injured hamstrings did display significant weakness eccentrically. Residual eccentric weakness may predispose this muscle group to reinjury during late swing, compared with the uninjured limb, because the functional eccentric demand on both limbs was similar. Furthermore, the EH/CHF ratios may better reflect muscle function during sprinting, having the potential to influence rehabilitation to prevent reinjury.

Medicine & Science in Sports & Exercise. 41(10):1942-1951, October 2009.

P W Kong, N G Candelaria, D R Smith  

In this study, the effect of shoe degradation on running biomechanics by comparing the kinetics and kinematics of running in new and worn shoes was investigated. Three types of footwear using different cushioning technologies were compared.

24 runners (14 male and 10 female) were tested Pre and post 200 miles of road running in the smae pair of shoes. The runners were given either air/gel/spring cushioned trainers. Testing consisted of overground running at 4.5 m s^–1 on a 20-m laboratory runway; performance measured using a force platform and a motion capture system.

Stance time was calculated from force data. External loads were measured by maximum vertical force and loading rate. Kinematic changes were indicated by sagittal plane angles of the torso, hip, knee and ankle at critical events during the stance phase.

Results demonstrated that stance time increases in worn shoes. The torso displayed less maximum forward lean and less forward lean at toe-off , while the ankle displayed reduced maximum dorsiflexion and increased plantar flexion at toe-off  in worn shoes. No changes in the hip and knee angles. No between-group difference among the three footwear groups or condition by type interaction was found in any measured variables.

The results show that as shoe cushioning decreases, runners change their pattern of running to maintain constant external loads. The adaptation strategies to shoe degradation were unaffected by different cushioning technologies, suggesting runners should choose running shoes for reasons other than cushioning technology.

British Journal of Sports Medicine 2009;43:745-749

Scott J. Luhmann, Perry L. Schoenecker, Matthew B. Dobbs, and J. Eric Gordon

The aim of this study was to determine the clinical presentation of adolescent patellofemoral pain.

Reviews were carried out over a three year period, of all patients with patellofemoral pain (PFP) at a childrens hospital sports clinic.

101 patients (91 female) with 136 symptomatic knees were assessed. Mean age was 14.4 years. Knee pain was localized to the anteromedial or anterior region of the knee in 96% of patients and was typically produced with running (94%), jumping (92%) and stair use (69%). On physical examination there was usually a non antalgic gait (99%), no patellofemoral crepitation (98%), normal lower extremity angular (84%) and rotational alignment (94%), with no foot malalignment (>97%). The medial patellofemoral ligament (MPFL) was the most palpably tender area of the knee in 98% of patients. During “lateral apprehension” testing, 89% had pain at the MPFL, but not true apprehension. A “J-sign” was present at terminal knee extension in 65%. Mean Q-angle was 18.7°. Means of all radiographic measures were within normal ranges.

Most commonly, patients complained of anterior/anteromedial knee pain of insidious onset during running and jumping. The most consistent physical findings were focal tenderness at the MPFL, positive terminal J-sign, and an elevated Q-angle. Most patients required only nonsurgical treatments, but 18% underwent surgical interventions for persistent pain.

J Child Orthop. 2008 August; 2(4): 269–277 

Hewett, TE, Torg, JS, & Boden BP

The position of the trunk and the knee during non-contact ACL injuries has not been examined before.

10 female, 7 male and 6 female controls were used. The participants were analysed for coronal and sagittal plane movement during landing and cutting tasks.

The results show that lateral trunk and knee abduction angles were higher in females than males during ACL injury. They also trended to be higher then the female control group. Female ACL-injured athletes also demonstrated less forwards lean than the female controls.

The study concludes that lateral trunk and knee abduction motion are important factors of the ACL injury mechanism in female athletes.

BJSM, 2009; 43: 417-422