This thesis is the culmination of a series of studies designed to improve the management of musculoskeletal (MSK) injury in an infantry training centre (ITC Catterick, UK). The overall aim of this thesis is to develop and evaluate a management strategy for MSK injury during Combat Infantryman’s Courses (CIC) training. Included is an epidemiological study of MSK injuries in the British Army (Study1), a risk factor model for MTSS (Study 2) and two randomised controlled trials (RCTs) in which the effects of prevention (Study 3) and rehabilitation interventions (Study 4) were examined. The aim of Study 1 was to quantify incidence, type and impact of the MSK injuries during military CIC training (26 weeks). Over a two year period (April 2006 -March 2008), 6608 British infantry CIC trainees completed an informed consent form to take part in this study. A prospective epidemiological study was conducted. Data for the injuries were reported according to: onset, anatomical location, diagnosis and regiment-specific incidence, week and months, impact and occupational outcome. It was clearly demonstrated that MSK injuries are a substantial burden to the British Army. Injury rate was 48.65% and overuse injury was significantly higher than acute and recurrence. Most overuse injuries occurred in the lower limb (82.34%) and were more frequent (p <0.01) in the first phase of training (Weeks 0-13). One third of the recruits (33%) were discharged prior to completion of training. A further 15% (n=991) were removed from training for further rehabilitation. Rehabilitation time ranged from 21 to 168 days and 12% of total training time was lost due to injury (equivalent to 155,403 days of training). Owing to its high severity index, medial tibial stress syndrome (MTSS) is argued to be the most impactful of these injuries despite only being second most frequent. Implications for practice and research (Study 1): MSK injuries are a significant burden to the British Army and strategies to improve prevention and treatment need to be explored. An initial focus on MTSS is warranted. In order to develop interventions for Studies 3 and 4 it is necessary to identify those risk factors for developing MTSS. The aim of Study 2 was to determine prospectively whether gait biomechanics and/or lifestyle factors can identify those at risk of developing MTSS. Again, British Infantry male recruits (n = 468) were selected for the study. Based on a review of the literature of known risk factors for MSK injury, plantar pressure variables, lifestyle factors comprising smoking habits and aerobic fitness as measured by a 1.5 mile timed-run were collected on the first day of training. A logistic regression model for membership of the MTSS and non-MTSS groups showed that an imbalance in foot pressure (heel rotation = pressure on the medial heel minus pressure on the lateral heel) was the primary risk factor for MTSS. Low aerobic fitness and smoking habit were also important, but were additive risk factors for MTSS. The logistic regression model combining all three risk factors was capable of predicting 96.9% of the non-injured group and 67.5% of the MTSS group with an overall accuracy of 87.7%. Implications for practice and research (Study 2): Foot pronation, as measure by heel rotation, is a primary risk factor for MTSS. Previous studies have shown that gait retraining can change risk factors for injury. The aim of Study 3 was to examine the effectiveness of gait retraining on reducing risk factors associated with MTSS and on reducing the incidence of MTSS during the subsequent 26 week training period. British Infantry recruits (n = 450) volunteered for the study and baseline plantar pressure variables were recorded on the first day of training. Based on the findings of Study 2, those with abnormal foot pronation at baseline (n = 134, age 20.1 ± 2.03 years; height 167 ±1.4 cm; body mass 67 ± 2.4 kg) were randomly allocated to an intervention (n = 83) or control group (n = 83). The intervention group undertook a gait retraining program which included targeted exercises three times a week and biofeedback on risk factors once per week. Both groups continued with the CIC training concurrently. Injury diagnoses over the 26 week training regimen were made by physicians who were blinded to the study. Post-measures of plantar pressure were recorded at 26 weeks. There was a significant reduction in the pronation (p <0.001) and overall difference survival function between MTSS and non-MTSS (Log rank test X2 = 6.12, p = 0.013). The absolute risk reduction was 60% in the intervention group. Implications for practice and research (Study 3): Gait retraining can reduce risk factors and incidence of MTSS injury. Based on such positive findings for the prevention of MTSS in Study 3, it was hypothesised that gait retraining may also have potential for the rehabilitation of MTSS. The aim of Study 4 was to examine the effectiveness of a gait retraining on plantar pressure variables, pain intensity and time spent in rehabilitation due to MTSS. Recruits diagnosed with MTSS but not responding to current treatment were eligible for this study (n = 66, age 20.85 ± 2.03 years; height 167 ±1.4 cm; body mass 67 ± 2.4 kg). The participants were randomly allocated to an intervention (n = 32) or control group (n = 34). In order to overcome the debilitating pain suffered by MTSS patients during exercise, the intervention group received a corticosteroid injection prior to the gait retraining programme. The control group continued with the current rehabilitation programme. There were significant improvements in terms of time to reach peak heel rotation (p<0.001), pain intensity (p<0.001) and positive occupational outcome in the intervention group (p<0.019). Implications for practice and research (Study 4): A combined corticosteroid-exercise intervention is beneficial in normalising plantar pressure, reducing rehabilitation times, pain intensity and occupational outcome of MTSS.
|Date of Award||30 Jul 2013|
|Supervisor||Iain Spears (Supervisor)|