That would account for his cane and his limp.

Someone imitated the Doctor's limp, and like all imitators, overdid it.

The faithful who sit idle, other than those who are disabled, are not equal to those who fight in the way of God with their wealth and lives.

Such believers as sit at home unless they have an injury are not the equals of those who struggle in the path of God with their possessions and their selves.

Not equal are the holders back among the believers, save those who are disabled, and the strivers in the way of Allah with their riches and their lives.

Not equal are those of the believers who sit (at home), except those who are disabled (by injury or are blind or lame, etc.), and those who strive hard and fight in the Cause of Allah with their wealth and their lives.

Not equal are the inactive among the believers except the disabled and the strivers in the cause of God with their possessions and their persons.

Those believers who sit at home, unless they do so out of a disabling injury, are not the equals of those who strive in the way of Allah with their possessions and their lives.

Those of the believers who sit still, other than those who have a (disabling) hurt, are not on an equality with those who strive in the way of Allah with their wealth and lives.

Not equal are those of the faithful who sit back excepting those who suffer from some disability and those who wage jihad in the way of Allah with their possession and their persons.