The present study provides a detailed clinical and functional assessment of a sample of 236 participants in a border area in Bangladesh who reported during a household survey  that they had been subjected to OPV and human rights violations during the past 38 years. We used a combination of physical examination and simple physical tests, a questionnaire and interviews to record the history and present situation of the participants and to assess their social and physical functioning and well-being.
The participants' reports did not only provide information about individuals, but about the wider history of OPV and human rights violations. The earliest reported incident in our study was in 1971. The first arrest reported in the patient records of the Bangladesh Rehabilitation Centre for Trauma Victims was also in 1971. There may have been incidents before the liberation war, but there is some doubt as to whether the victims are still alive. In our study, only a few incidents were reported from 1971 to 1990. From 1991 to 1995 there were still relatively few, but the frequency doubled in 1996-1999, and since 2000, the reported numbers have increased sharply. The years 1971, 1990-91, 1996-97 and 2000-01 are crucial in the history of OPV and human rights violations in the whole of Bangladesh. In these years, there was a high level of political tension and violence; this pattern is shown in our study and also reported by other institutions [11, 12, 25, 26]. There were general elections in Bangladesh in 1991, 1996 and 2001, which were wrecked by pre and post-election violence. Over 80% of the participants in our study claimed to be "party supporters" but only a few of them revealed which political party they supported. Therefore we were unable to do further analysis to test our hypothesis that the supporters of an opposition party were more likely to be victimised as the political tension increased sharply in the year of general elections.
Human rights violations including the use of TCIDTP have intensified in the last five years in Meherpur district since Operation Spider Web was launched, and violence and crime have been aggravated. Since 2006, the enforcement of strict emergency regulations by a care-taker government has increased the brutality of violent confrontations.
The results also showed a seasonal pattern. The number of reported cases was three times higher during the winter season than during the rainy season. It is clear that the police and the military are hampered by the flooding and uncomfortable conditions during the rainy season.
From the results of our study it appeared that the police were the major perpetrators. Individuals could be attacked by armed militias associated with party politics, but such incidents were not reported here. Such individuals were not likely to present in the mobile clinic, because the recruitment criteria were primary or secondary victims subjected to any of four categories of OPV and human rights violations perpetrated by the members of law enforcement agency. Mitchell (2004) pointed out that the degree of political control that the political authorities exercise over a law enforcement agency varies across time and political system. It is plausible that if individuals in a law enforcement agency have goals independent of those of the authority, or have private interests, this may influences the choice, level and method of violence .
The survey provided detailed information about the methods used by the perpetrators. A previous study in Sri Lanka suggested that perpetrators generally use readily available materials as TCIDTP instruments . Methods gain popularity if they cost nothing, are available anywhere at any time, can achieve maximum effect, and rarely leave clear evidence, e.g., falanga (beating the soles of the feet) or being kicked.
Forced sexual contact and sexual abuse are also frequently-used forms of torture. It was reported that all of the female refugees and one-third of the male refugees from Bangladesh examined at the Centre for Torture and Trauma Survivors in Stockholm alleged that they had been raped . In our study, few participants reported that they had been sexually harassed, abused or raped. However, owing to the social stigma involved, victims may not admit to being raped or sexually abused by members of a law enforcement agency unless they are far away from the perpetrators and from their own community. This helps to explain the low number of cases identified in our study. Among them, there were more males (n = 12) than females (n = 4). Rape and sexual abuse of males is not rare: it was shown that 22% of inmates in Nebraska, USA in 1996  and 21% Tamil detainees in Sri Lanka reported at least one episode of forced sexual contact . Up to now, the epidemic character of using male rape and sexual abuse as a weapon in the conflict setting [32–34] and in closed environments,i.e. detention and prison, has been neglected by the authorities. A low level of control of corruption in the administration is likely to provide the members of law enforcement agency with a wealth of opportunities for hidden actions including the perpetration of sexual violence . It is also plausible that in the society in which homosexuality is not approved of, the setting of detention and prison allows the individuals of law enforcement agency who seek for particular sexual interest to conceal their actions.
Very little is known about the physical and emotional consequences and social functioning of an oppressed population experiencing collective exposure to OPV and human rights violations. The rehabilitation of TCIDTP victims has been mainly based on clinical experiences seen from an illness perspective. For people who continue to live in their communities, it is most important that they should be able to maintain daily life after being traumatised. A basic level of muscle strength and physical mobility is required, simply to be able to cope with the activities of daily life.
In our study we assessed muscular function by measuring handgrip strength, which is required in many daily activities in a rural area. Hand dynamometer testing is recommended to determine the loss of handgrip strength [36–38]. This method is widely used for outcome documentation after injuries of the upper extremities , as a functional index of nutritional status, and for determination of impairment . Our study was the first to use the method to investigate loss of muscle strength in a survey of a population exposed to massive OPV and human rights violations. Because standard normative values for healthy adults for all age groups in Bangladesh or in South Asia are not available, we used values for young and middle aged male adults in West Bengal . Our survey participants showed lower muscle strength in their dominant hands. However, we did not determine whether the reduced muscle strength was the consequence of the traumatic experience, and a further study with a control group is needed.
Our study was also the first to assess standing balance performance in an oppressed population. Impaired lower extremity performance is associated with reduced physical activity levels, which may contribute to subsequent disability in elderly persons [41, 42]. Standing balance is related to physical fitness and consequently to social life [43, 44]. Many participants reported lower back, leg and knee injuries, which can affect standing balance. We found evidence that there was an association between objective measurements of standing balance performance and self-reported walking performance, which also indicated the reliability of subjective difficulty measured and reported by the victims. The standing balance test is a simple rapid assessment tool and could be considered as an instrument to be used routinely in the initial functional assessment procedure of victims of torture or other forms of violence. We recommend conducting a comprehensive balance and mobility assessment when standing balance performance of a victim is poor even after adjustment for age and BMI.
The measures used to test muscle strength and physical mobility in our survey are rapid and inexpensive, so they are appropriate for use in countries with limited resources. Such tests can be used to produce essential information for purposes of diagnosis and prognosis, as well as for prevention and rehabilitation. The results could also contribute to quantifying the economic burden in terms of disability and manpower lost due to OPV and human rights violations, and their association with poverty in a country such as Bangladesh.
A person's functioning does not only depend on muscular strength but also on emotional factors. We used the brief questionnaire "WHO-5 Well-being" to estimate the percentage of victims with poor subjective emotional well-being, and to examine the association of subjective emotional well-being with social participation. Emotional, physical, and social vulnerability as a consequence of being abused is related to the development of post-trauma stress disorder and other mental disorders. The inter-personal and inter-family conflicts are high in the study area. In order to develop programmes which can help to reduce the damage to emotional health and to prevent its harsher effect on mental health, we need to understand what factors may empower victims to cope with their vulnerability.
One factor that we considered was active participation in political or social movements. The effects of political and social participation on well-being are complex. On the one hand, in the household survey we found that if a family member was affiliated to a political party or participated in a demonstration, a strike or a human rights rally, this was a risk factor for victimisation . On the other hand, the present study found that participation in a political or social movement was linked to improved emotional well-being; it could strengthen people's self-confidence and restore their interest in social justice and the environment. Many trauma victims have a poor self-image and low self-esteem. Organising or taking part in a demonstration, a strike or a human rights rally allows participants to share and release their feelings of stress and frustration, to express their anger in a collective voice, and to bond with others and create alliances. Participation can empower the victims and thus improve their emotional well-being. These interactions demonstrate the complexity of the factors that determine emotional well-being; on the one hand, the patterns of political or social participation affect the emotional well-being of trauma victims, but, on the other hand, their emotional well-being also determines the personal, social, and behavioural competence in relationships and the capacity to deal constructively with a challenging or difficult situation [45, 46].
Limitations and strengths
Our findings concerning perpetrators and years of perpetrations were consistent with reports from other international institutions [11, 12, 25, 26] and also from a local human rights organisation, Odhikar. A medical examination that found traces of injury is also a validation of the oral reports. We used simple physical tests to confirm the reliability of subjective difficulty in walking reported by the study participants.
One limitation was that owing to logistical and political constraints, we did not recruit people without prior TCIDTP experience as a healthy control group while taking into account neighbourhood effect on OPV or human rights violations. In addition, there was inevitably some risk of bias in the recruitment of the study group. The health-seeking behaviour of the individuals concerned is one possible source of bias. We do not know why some who had vouchers decided not to come to the mobile clinic. Some of them may have been so severely depressed that they lacked any motivation to come - and others may have seen no need to interrupt their work to come to the clinic. It is also possible that there was some bias because a few participants exaggerated their injuries and pain experiences in order to receive more treatment. Memory bias does exist, but the main increase in OPV and human rights violations in this area took place within the last 10 years, and ten-year recall is considered reliable .
We had hoped to use the results as a baseline for a large-scale intervention in this community, and to repeat the measurements afterwards to monitor the quality and outcome of rehabilitation. We had already developed plans for various interventions including setting up a platform, Victim Association, where the survivors can talk about their fears and stigmas and re-construct their self-images, and which will also serve as a place for social participation and political empowerment. The members should assist the Victim Association to raise the community awareness and spread knowledge about human rights by organising various community activities. Unfortunately, these cannot immediately be realised for unexpected reasons