The two, as well as Lacaba, are staff of the International Committee of the Red Cross (ICRC).
"I'm really very elated. I'm so happy and had a good cry," Senator Richard Gordon, head of the Philippine Red Cross, said.
He also urged the hostage-takers not to harm the remaining captives.
"I'm appealing to them not to harm them and I also appeal to the military also to take it slowly and let's not act if it's dangerous."
Abu Sayyaf, which is alleged to have al-Qaeda links, had earlier said it would behead one of the ICRC workers if Philippine troops did not retreat from Jolo by Tuesday.
The military made a partial withdrawal from five towns, but there has been no word, so far, from the group on whether they have carried out the threat.
"She is being attended to by doctors and she was able to talk to a colleague at the International Committee of the Red Cross and to her husband"
Lieutenant-General Nelson Allaga,
The three were kidnapped while heading to a local airport after visiting an ICRC water-sanitation project at the provincial jail.
Footage of Lacaba, shown on GMA-7 television on Thursday, showed her being pushed in a wheelchair to a trauma clinic in the Jolo military camp.
"Right now she is resting," Lieutenant-General Nelson Allaga, the Philippine military commander for the region, said.
"She is being attended to by doctors and she was able to talk to a colleague at the International Committee of the Red Cross and to her husband."
Al Jazeera's Marga Ortigas, reporting from the capital Manila, said: "The government is actually feeling rather hopeful that the pressure it has been putting on the group over the last few weeks is possibly bearing fruit and they are beginning to crack.
"They have been coming out in the media here and saying that they believe that one of the senior leaders of the group has been seriously injured in a firefight and the leadership of the group is breaking down.
"The Abu Sayyaf, from what the military has said, has actually run away from one of its camps heading deeper into the jungle."
State of emergency
Earlier in the week, Abdusakur Tan, the governor of southern Sulu province, said the group and the hostages were on the run as the government redeployed troops around a hilly area on the island close to their camp.
Tan had declared a state of emergency on Tuesday, hours after the beheading deadline set by the captives lapsed.
Abu Sayyaf has beheaded hostages in the past, including an American in 2001 and seven Filipinos in 2007.
The group, which is also said to have links to the regional Jemaah Islamiyah group, has been blamed for the worst attack in the Philippines' history, in which a ferry in Manila Bay was bombed in 2004, killing 100 people.
The US government has placed the group, which is believed to have about 400 fighters, on its list of terrorist organisations.